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High-quality, in-plane semiconductor lasers exhibit improved performance over a wide range of emission wavelengths from ultraviolet into the THz range. Devices are finding an ever-increasing number of applications in, for example, telecommunications, printing, spectroscopy, displays, and medical diagnostics and therapy.

Well-developed GaAs- and InP-based lasers operating from the 0.8 to 2-μm are achieving multi-watt output powers with beams of high spatial and spectral purity. Lasers made from material systems, such as dilute nitride-antimonides, bismides or quantum-dot active regions, are pushing performance and spectral coverage. Mode-locked diode lasers are demonstrating improvements such as reduced pulse length and timing jitter. Applications in communication are pushing advances in laser dynamics, including the use of coupled and/or chaotic semiconductor lasers. The GaN based laser field continues to innovate and make progress in terms of e.g. power, reliability and to extend operation deeper into the orange and the ultraviolet parts of the spectrum. In the infrared, Sb-based quantum well lasers display high performance at wavelengths up to ~ 5 μm, and quantum cascade lasers operate at wavelengths from just below 3 μm to almost 300 μm. Emerging applications in the mid/far-infrared stimulate the development of high-efficiency, high-power quantum cascade lasers operating at an ambient temperature and with new functionalities such as ultrashort pulse generation, frequency combs, injection locking, and beam control. Novel laser sources utilize recent advances in plasmonics, nanophotonics, topological photonics, and nonlinear optics for efficient generation and manipulation of light. A variety of approaches for silicon-based lasers, including hybrid structures by local area growth or wafer bonding are yielding advancing performance. Laser sources based on novel two-dimensional and topological materials are showing promise.

This conference provides a forum for the most recent breakthroughs in device design and performance. We solicit papers describing novel designs that achieve higher performance levels and unique operational characteristics, as well as papers describing the technical limitations of the current in-plane laser technology and lasers tailored to particular applications such as heat-assisted magnetic recording or neuromorphic computing. We are interested in new methods of fabrication or new methods of characterization that are necessary for improved performance. Papers of experimental and/or theoretical nature are welcome.

Examples of in-plane laser types of interest include, but are not limited to: ;
In progress – view active session
Conference 12021

Novel In-Plane Semiconductor Lasers XXI

In person: 25 - 27 January 2022
View Session ∨
  • 1: DFB and DBRs
  • 2: Materials and Structure Development
  • 3: Advances in QCL Frequency Combs
  • 4: QCLs and Other Mid-IR Lasers: New Physics
  • 5: Lasers for Integration
  • 6: THz QCL Frequency Combs
  • 7: THz Lasers
  • 8: Mid-IR Lasers and Integrated Systems
  • Posters-Wednesday
  • 9: High Brightness
  • 10: Mid-IR QCLs: Modeling and New Architectures
  • 11: Mid-IR QCLs and Applications


  • Submissions are accepted through 06-December
  • Notification of acceptance by 20-December

View Call for Papers PDF Flyer
Session 1: DFB and DBRs
Session Chair: Johann Peter Reithmaier, Univ. Kassel (Germany)
Author(s): Shenghong Ye, Ming Che, Takeshi Kuboki, Kazutoshi Kato, Kyushu Univ. (Japan)
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To realize a high-speed high-reliability wavelength switching at a future WDM networks, we proposed the injection current/temperature cooperative control method of the tunable-distributed-feedback (DFB) laser array (TLA) for reducing the large injection current which is the primary cause of laser degradation. We successfully demonstrated a full-c-band wavelength switching within a short time of 124 ms and following injection current reduction from 420 to 63 mA. Compared to the conventional control method, the mean time to failure of the TLA in the proposed method is estimated to be extended by 44 times.
Author(s): Takahiko Shindo, Yuta Ueda, NTT Device Innovation Ctr. (Japan); Makoto Shimokozono, NTT Device Technology Labs. (Japan); Wataru Kobayashi, Tomonari Sato, NTT Device Technology Labs. (Japan); Shigeru Kanazawa, Mingchen Chen, NTT Device Innovation Ctr. (Japan); Hideaki Matsuzaki, NTT Device Technology Labs. (Japan)
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We demonstrated a 2-μm wavelength InGaAs-InGaAs superstructure grating (SSG-) distributed Bragg reflector (DBR) laser with stable single-mode operations across a 53-nm tuning range. We adjusted the wavelength detuning to make the lasing performance uniform across the tuning range. As a result, side-mode suppression ratios (SMSRs) exceeding 30 dB were achieved for all 40 consecutive wavelength channels with 100 GHz spacing from 1978.4 to 2031.0 nm. The fluctuation of the light intensity during wavelength tuning was also suppressed to less than 6.5 dB, which is much lower than that in the previous report (>15 dB).
Author(s): André Müller, Martin Maiwald, Bernd Sumpf, Ferdinand-Braun-Institut (Germany)
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An electrically wavelength tunable DBR ridge-waveguide laser suitable for multi-wavelength excitation Raman spectroscopy near 785 nm is presented. The 3 mm long device consists of a 2.2 µm wide ridge waveguide and a 10th order DBR surface grating. Resistors implemented near the grating enable flexible wavelength tuning by Joule heating. At 25°C heat sink temperature, laser emission with 100 mW optical output power and a spectral width of 20 pm is obtained. A current of 0.6 A applied to the resistors results in 2.2 nm wavelength tuning. Single emission wavelengths can be adjusted with time constants of about 500 ms.
Author(s): Freddie Castillo, Maryam Dezfuli, Weida Zhang, Scott McWilliams, Southern Methodist Univ. (United States); Ralph Johnson, Photon Sciences Inc. (United States); Nai-Hsiang Sun, I-Shou Univ. (Taiwan); Jerome K. Butler, Gary A. Evans, Southern Methodist Univ. (United States)
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A low index layer between the boundary of a first-order grating combined with a high index cover layer provides significantly higher reflected power per unit length and reduces losses at the waveguide-grating interface compared to conventional gratings in III-V waveguides. The dependence of the peak and spectral width of the reflected power for Enhanced Coupling Strength (ECS) gratings is analyzed for two different ECS grating geometries. These properties of ECS gratings allow integration of optical components such as high-speed modulators with short horizontal cavity lasers that can operate without temperature control over wide temperature and wavelength ranges.
Author(s): David Childs, Calum Hill, Jon Orchard, Vector Photonics Ltd. (United Kingdom); Katherine Rae, Daehyun Kim, Neil Gerrard, Zijun Bian, Jingzhao Liu, Aye Kyaw, James Grant, Ben King, Stephen Thoms, Paul Reynolds, Univ. of Glasgow (United Kingdom); Adam McKenzie, Univ. of Glasgow (United Kingdom), Sivers Photonics Ltd. (United Kingdom); Richard Taylor, Vector Photonics Ltd. (United Kingdom); Richard Hogg, Univ. of Glasgow (United Kingdom), Vector Photonics Ltd. (United Kingdom)
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In this paper we present for the first-time high-speed modulation results for Photonic crystal surface emitting lasers (PCSELs) emitting at 940 nm, a 3dB bandwidth of 4.2 GHz was measured at a drive current of 2.2 x Ith for a device not optimised for high-speed operation. Extracting the ‘K factor’ from the measurements yields a damping limit to device operation of approximately 25GHz. We go on to show that careful optimization of device design, namely increasing differential gain and decreasing mode volume, can yield PCSEL devices with direct modulation bandwidths of 50-100 GHz.
Author(s): Nils Surkamp, Alexandra Gerling, Ruhr-Univ. Bochum (Germany); Martin Honsberg, Sebastian Schmidtmann, Sacher Lasertechnik GmbH (Germany); Uttam Nandi, Sascha Preu, Technische Univ. Darmstadt (Germany); Joachim Sacher, Sacher Lasertechnik GmbH (Germany); Carsten Brenner, Martin R. Hofmann, Ruhr-Univ. Bochum (Germany)
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A slotted Y-branch laser providing two-color emission in the 1550 nm region with an optical beat frequency of 1 THz is characterized and used as a photonic source for thickness measurements of high resistive silicon wafers with continuous wave Terahertz radiation. Frequency tuning is obtained through segment current tuning of the individual branches. Determination of the refractive index and thickness is obtained by MSE fitting of the theoretical etalon transmission to the experimental measurements without additional knowledge.
Session 2: Materials and Structure Development
Session Chair: Peter M. Smowton, Cardiff Univ. (United Kingdom)
Author(s): Vinayakrishna Joshi, Institute of Nanostructure Technologies and Analytics (Germany); Sven Bauer, Vitalii Sichkovskyi, Florian Schnabel, Anna Sengül, Institute of Nanostructure Technologies and Analytics (Germany); Johann Reithmaier, Institute of Nanostructure Technologies and Analytics (Germany)
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InP-based quantum dot (QD) laser devices emitting at 1.3 µm were realized by incorporating a GaAs nucleation layer underneath the InAs QD layers. A good carrier confinement while retaining the waveguiding properties is achieved by embedding the QDs in In0.528Al0.371Ga0.101As. Length dependent P-I characteristics yielded static parameters, which were comparable to static parameters obtained for InP-based lasers emitting at 1.55 µm. Additionally, temperature dependent measurements were conducted and evaluated. The lasers show ground mode lasing up to high operation temperatures with good temperature stability of the threshold current density and external quantum efficiency.
Author(s): Cody Hammack, Levon V. Asryan, Virginia Polytechnic Institute and State Univ. (United States)
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The parasitic electron-hole recombination outside of a quantum-confined active region still presents a challenge in conventional injection lasers. The use of asymmetric barrier layers (ABLs) (one on each side of the active region) should efficiently suppress this recombination. However, even in lasers with ABLs, excited states may be present in the active region in addition to the ground state. Excited states may strongly affect delivery of charge carriers to the lasing ground state. In this work, dynamic properties of quantum dot (QD) lasers with ABLs are studied in the presence of excited states in QDs. The situation is considered when the carrier capture into the lasing ground state in QDs is excited-state-mediated. It is shown that the modulation bandwidth of the ABL QD laser can be considerably impacted by excited-to-ground state relaxation delay in QDs. Hence a strict control of the intradot relaxation time will be required to enhance the modulation bandwidth in ABL QD lasers.
Author(s): Lydia K. Jarvis, Ben Maglio, Samuel Shutts, Zhibo Li, Cardiff Univ. (United Kingdom); Huiwen Deng, Mingchu Tang, Huiyun Liu, Univ. College London (United Kingdom); Peter Smowton, Cardiff Univ. (United Kingdom)
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The performance of O-band InAs/GaAs quantum-dot (QD) lasers grown by molecular beam epitaxy with three different doping strategies are investigated in a temperature range 17 °C – 97 °C. We demonstrate lasers with a reduced threshold current using direct n-doping (during the dot formation) in the active region compared lasers with a nominally undoped active region. We explain results using calculations of the dot and wetting layer potentials and the electron and hole energy levels.
Author(s): Manuel Fregolent, Matteo Buffolo, Carlo De Santi, Univ. degli Studi di Padova (Italy); Sho Hasegawa, Junta Matsumura, Hiroyuki Nishinaka, Masahiro Yoshimoto, Kyoto Institute of Technology (Japan); Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini, Univ. degli Studi di Padova (Italy)
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In this paper we analyze the deep levels within bandgap in n-type GaAsBi Schottky Barrier Diodes by means of capacitive deep level transient spectroscopy. We proved that in the probed semiconductor region are present four majority and two minority traps with concentration below 10^14 cm^-3. Moreover, the carrier capture kinetic of the defects indicate that the dominant electron trap and hole traps are associated respectively to a dislocation and a point defect with capture barrier. By comparing our results with other literature reports, we also found that only one trap may be associated with the presence of bismuth.
Author(s): Jonathan R. C. Woods, Jon Gorecki, Jake Daykin, Stephen Richardson, Univ. of Southampton (United Kingdom); Michael Jetter, Univ. Stuttgart (Germany); Roman Bek, Twenty-One Semiconductors GmbH (Germany); Emelia Branagan-Harris, Grace Hooper, Univ. of Southampton (United Kingdom); James S. Wilkinson, University of Southampton (United Kingdom); Anne C. Tropper, Vasilis Apostolopoulos, Univ. of Southampton (United Kingdom)
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Optically pumped waveguide coherent laser arrays are demonstrated in an 1-micron-thick-semiconductor-membrane-InGaAs-quantum-well laser transferred on a silicon carbide heat spreader emitting at 1010 nm. We employ a real and Fourier space imaging setup to study the emission of single and arrays of laser cavities. We are able to create waveguide laser arrays with modal widths of approximately 5-10 μm separated by 5-10 μm which maintain their mutual coherence while operating on either single or multiple longitudinal modes. This laser geometry can be accurately controlled by the laser pump and they offer a new high gain laser platform that permits integration with photonic structures.
Session 3: Advances in QCL Frequency Combs
Session Chair: Giacomo Scalari, ETH Zurich (Switzerland)
Author(s): Jérôme Faist, ETH Zurich (Switzerland)
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Quantum cascade laser combs enable the generation of high average power coherent optical frequency combs. Combination of RF injection in specially designed devices enable the recompression of the emission into high peak power pulses for non-linear optics applications. A combination of techniques are used to analyse the temporal profile of the emission.
Author(s): Benedikt Schwarz, Maximilian Beiser, Florian Pilat, Nikola Opacak, Sandro D. Cin, Johannes Hillbrand, Technische Univ. Wien (Austria); Dmitry Kazakov, Marco Piccardo, Federico Capasso, Harvard Univ. (United States)
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Frequency combs are ideal candidates to realize miniaturized spectrometers without moving parts and hence are of great interest for integrated photonics. Most comb research is focused on the generation of pulses. However, frequency combs can also exhibit a very different behavior that is characterized by a continuous output intensity – the frequency modulated (FM) combs. The two states are characterized by in-phase or anti-phase couplings. Here, an overview on our experimental investigations on semiconductor frequency combs to identify the key roles of parameters such as the linewidth enhancement factor and how the bandwidth of such combs can be optimized is given.
Author(s): Dmitry Kazakov, Harvard Univ. (United States); Maximilian Beiser, Nikola Opacak, Technische Univ. Wien (Austria); Yiyang Zhi, Case Western Reserve Univ. (United States); Massimo Brambilla, Politecnico di Bari (Italy); Lorenzo Columbo, Politecnico di Torino (Italy); Benedikt Schwarz, Technische Univ. Wien (Austria); Alexey Belyanin, Texas A&M Univ. (United States); Marco Piccardo, Istituto Italiano di Tecnologia (Italy), Harvard Univ. (United States); Federico Capasso, Harvard Univ. (United States)
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The recent generalised theory of frequency comb generation in externally pumped cavities with and without population inversion suggested an intimate link between quantum cascade lasers (QCLs) and Kerr resonators. In this talk we overview recent experimental developments in chip-scale ring cavity QCLs with and without output coupling ports, that allow operation in self-pumped and externally pumped configurations, and their ability to support cavity solitons.
Session 4: QCLs and Other Mid-IR Lasers: New Physics
Session Chair: Benedikt Schwarz, Technische Univ. Wien (Austria)
Author(s): Lorenzo Luigi L. Columbo, Politecnico di Torino (Italy); Marco Piccardo, Ctr. for Nano Science and Technology, Istituto Italiano di Tecnologia (Italy); Massimo Brambilla, Politecnico di Bari (Italy), CNR-Istituto di Fotonica e Nanotecnologie (Italy); Franco Prati, Univ. degli Studi dell'Insubria (Italy); Carlo Silvestri, Mariangela Gioannini, Politecnico di Torino (Italy); Alessandra Gatti, Luigi Lugiato, Univ. degli Studi dell'Insubria (Italy); Federico Capasso, Harvard John A. Paulson School of Engineering and Applied Sciences (United States)
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We report on self-organization phenomena in a coherently driven unidirectional ring Quantum Cascade Laser. In particular our simulations based on a generalized Lugiato-Lefever equation show the existence in the intracavity field profile of Cavity Solitons (CSs) and Turing patterns previously identified in Kerr micro-resonators. In the perspective of applications in e.g. information processing, high precision spectroscopy and wireless communications, we demonstrate the external addressing of one or more CS and we investigate the possibility to exploit their universal properties as dissipative localized structures to manipulate the spectral content of the associated optical frequency combs.
Author(s): Nikola Opacak, Sandro Dal Cin, Technische Univ. Wien (Austria); Johannes Hillbrand, ETH Zurich (Switzerland); Gottfried Strasser, Benedikt Schwarz, Technische Univ. Wien (Austria)
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Optical frequency combs are perfectly periodic waveforms of light. These waveforms can be formed due to optical nonlinearities, which provide coherent coupling of the amplitude and phase of the light. We show that Bloch gain serves as the physical origin of the linewidth enhancement factor and yields a giant Kerr nonlinearity, which plays an essential role in the formation of quantum cascade laser combs. We develop a laser master equation to self-consistently include the Bloch gain. Our results explain the generation of self-starting combs in Fabry-Perot QCLs, and the emission of localized structures in ring resonators, akin to dissipative Kerr solitons.
Author(s): Alexey Belyanin, Texas A&M Univ. (United States); Mikhail Tokman, Institute of Applied Physics of the RAS (Russian Federation); Yongrui Wang, Qianfan Chen, Texas A&M Univ. (United States); Leon Shterengas, Stony Brook Univ. (United States)
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We propose and design a high-brightness, ultra-compact electrically pumped GaSb-based laser source of polarization-entangled photons generated by intracavity parametric down-conversion of lasing modes. We develop a nonperturbative quantum theory of parametric down-conversion of waveguide modes which takes into account the effects of modal dispersion, group and phase mismatch, propagation, dissipation, and coupling to noisy reservoirs. We provide convenient analytic expressions for interpreting experimental results and predicting the performance of monolithic quantum photonic devices based on nonlinear wave mixing of laser modes.
Session 5: Lasers for Integration
Session Chair: Haisheng Rong, Intel Corp. (United States)
Author(s): Jonathan Klamkin, Si Zhu, Bei Shi, Lei Wang, Bowen Song, Univ. of California, Santa Barbara (United States)
Author(s): Matteo Buffolo, Michele Zenari, Carlo De Santi, Univ. degli Studi di Padova (Italy); Justin Norman, Quintessent Inc. (United States); John E. Bowers, Univ. of California, Santa Barbara (United States); Robert W. Herrick, Intel Corp. (United States); Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini, Univ. degli Studi di Padova (Italy)
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This work investigates on the impact of temperature and of diffusion processes on the optical degradation of 1.3 um InAs quantum-dot lasers epitaxially grown on silicon. By means of a series of constant-current stress experiments carried out at different temperatures we were able to ascribe the peculiar temperature activation of the detected threshold current degradation process to a recombination-enhanced diffusion process, driven by the escape of carriers from the InAs QDs. The comparison of the experimentally-determined diffusion coefficient with the literature ultimately allowed us to relate the Ith degradation to the p-dopant Be, or to defects determining its diffusivity.
Author(s): Cristina Rimoldi, Politecnico di Torino (Italy); Lorenzo L. Columbo, Politecnico di Torino (Italy); Jock Bovington, Cisco Systems, Inc. (United States); Sebastian Romero-Garcia, Cisco Systems, Inc. (Germany); Dominic Siriani, Cisco Systems, Inc. (United States); Mariangela Gioannini, Politecnico di Torino (Italy)
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We study the stability of a hybrid laser source consisting of a III-V RSOA edge-coupled to a SiN Mach-Zehnder interferometric mirror, loaded by two high-Q microring resonators, providing a narrow band effective reflectivity. We simulate the laser dynamics through a model of time-delayed algebraic equations accounting for the frequency-selective mirror reflectivity and identify the best regions of CW operation in terms of bias current, mirror bandwidth, and laser detuning with respect to the reflectivity peak. Finally, we test the CW laser stability with respect to optical feedback, mimicking the effect of spurious back-reflections from the passive parts of the circuit.
Author(s): Joel Hazan, Technische Univ. Eindhoven (Netherlands); Tancrede Couka, Ecole Nationale Supérieure d'Ingenieurs de Caen et Ctr. de Recherche (France); Rastko Pajkovic, Kevin Williams, Erwin Bente, Technische Univ. Eindhoven (Netherlands)
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In this work we present results of different control strategies with the aim to achieve single mode lasing wavelengths with 10 GHz spacing (90 pm) between 1480 and 1570 nm, on an InP monolithically integrated widely tunable laser system for optical coherence tomography (OCT) applications. To tune the laser, we apply 8 reversely bias voltage control settings on electro-refractive modulators which are responsible for the laser wavelength selection, with low thermal dissipation. The OCT requirements of a 1 GHz resolution and stable calibration are addressed, and two different strategies to select the lasing wavelengths, over its tuning range, are discussed.
Author(s): Laurent Cerutti, Daniel A. Diaz-Thomas, Jean-Baptiste Rodriguez, Marta Rio-Calvo, Alexei N. Baranov, Eric Tournié, Univ. de Montpellier (France)
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We report a type-II interband cascade laser grown on an on-axis silicon substrate. We demonstrate continuous-wave lasing operation at temperatures up to 50°C at 3.5µm with a threshold current of 45 mA at room temperature and 20 mW/facet output power. We extrapolate a mean time to failure of at least 300,000 h, which we attribute to the design of the active region eliminating the non-radiative recombination process.
Session 6: THz QCL Frequency Combs
Session Chair: Nikola Opacak, Technische Univ. Wien (Austria)
Author(s): Giacomo Scalari, Andres Forrer, Urban Senica, ETH Zurich (Switzerland); Guido Torrioli, Sara Cibella, CNR-Istituto di Fotonica e Nanotecnologie (Italy); Paolo Micheletti, Mattias Beck, Jerome Faist, ETH Zurich (Switzerland)
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In this work present high performance QCL-based THz combs operating on fundamental and harmonic comb states operating up to 110 K in the spectral region from 2 to 4 THz . We employ double-metal, Copper- based laser resonators planarized with a polymer allowing high performance with CW operation up to 118 K . Such waveguide layout allows as well optimized RF coupling facilitating injection of high RF power. We analyze the laser emission by means of SWIFTS technique employing an Hot-Electron-Bolometer based on NbN. Different regimes are observed as the RF injection power is increased, going from FM emission to a pure AM. Spectral bandwidths as large as 700 GHz are observed corresponding to a fully coherent laser operation. For specific waveguide geometries and injection conditions pulses as short as 4 ps are observed. We present as well SWIFTS measurements for THz QCL combs operating on harmonic states under RF injection at the harmonic frequency of 17.6 GHz.
Author(s): Sukhdeep S. Dhillon, Lab. de Physique de l'Ecole Normale Supérieure (France)
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Millimeter wave (mmWave) generation using photonic techniques has so far been limited to the use of near-infrared lasers that are down-converted to the mmWave region. However, such methodologies do not currently benefit from a monolithic architecture and suffer from the quantum defect. Here we show how miniaturized terahertz (THz) quantum cascade lasers (QCLs) can open up the possibility of ntegrating both laser action and mmWave generation in a single device. We demonstrate intracavity mmWave generation within THz QCLs over the unprecedented range of 25 GHz to 500 GHz using their inherent giant nonlinearities.
Author(s): Miriam S. Vitiello, Istituto Nanoscienze (Italy)
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INVITED TALK This talk will review our recent developments in engineering and devising novel highly efficient broadband QCL resonators, behaving as frequency combs at THz frequencies, with > 100 μW optical powers per mode and a record dynamic range. Novel architectures, exploiting exotic device technologies, advanced materials and/or physical phenomena will be discussed, highlighting the promising role of THz frequency combs in quantum science, hyper-spectral imaging and dual-comb spectroscopy.
Session 7: THz Lasers
Session Chair: Dmitry Kazakov, Harvard John A. Paulson School of Engineering and Applied Sciences (United States)
Author(s): Benedikt Limbacher, Michael Jaidl, Marie Ertl, Martin Kainz, Sebastian Schönhuber, Juraj Darmo, Aaron M. Andrews, Gottfried Strasser, Karl Unterrainer, Technische Univ. Wien (Austria)
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The study of high Al containing barriers in Terahertz Quantum Cascade lasers has led to the improvement of operation temperature and of the quantum efficiency. This is mainly caused by the reduction of transport channels through higher states. In consequence, the electron transport in these new devices is dominated by photon assisted tunneling. The originating non-linearity provides a huge potential for different operation modes. We try to further study this by coupling distributed QCL devices on a chip which has led to the observation of bi-stable operation and THz switching. We use the non-linear behavior for the control of the emission spectra of surface emitting random laser structures. Furthermore, ring structures can be realized which can be tuned from single mode to frequency comb operation.
Author(s): Sushil Kumar, Lehigh Univ. (United States)
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Different phase-locking schemes are developed for surface-emitting terahertz quantum-cascade lasers (QCLs) with watt-level output power and radiating in symmetric single-lobed beams. In the first-scheme, multiple metallic microcavities are coupled through surface-plasmon-polaritons traveling in surrounding medium of cavities, that leads to peak-power output of 2.03W for a single-mode 3.3THz QCL with a slope-efficiency of 1.57W/A. In the second-scheme, a phase-locking scheme with hybrid second- and fourth-order Bragg gratings is demonstrated to realize a multi-mode surface-emitting THz QCL with 2.13W output power. Both QCLs operate at ~60K. Preliminary data for a scheme to achieve electrical tunability of such lasers is also reported.
Author(s): Paul Chevalier, Arman Amirzhan, Harvard Univ. (United States); Jeremy Rowlette, H. Ted Stinson, Michael Pushkarsky, Timothy Day, DRS Daylight Solutions (United States); Henry Everitt, Duke Univ. (United States); Federico Capasso, Harvard Univ. (United States)
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The THz region of the electromagnetic spectrum has been underutilized due to the lack of proper sources. The quantum cascade laser pumped molecular laser uses QCLs to pump a molecular gain medium in order to obtain laser emission at discrete THz frequencies separated by twice the rotational constant of the molecule. Following an initial proof of concept of a quantum cascade laser pumped molecular laser,in 2019, we now report significantly improved power levels while maintaining multi-line lasing spanning from 250 GHz up to 5 THz depending on the chosen gain medium.
Author(s): Yu Wu, Univ. of California, Los Angeles (United States); Sadhvikas Addamane, John L. Reno, Sandia National Labs. (United States); Benjamin S. Williams, Univ. of California, Los Angeles (United States)
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A terahertz quantum-cascade VECSEL is demonstrated to exhibit multi-mode operation, despite the fact that spatial-hole burning is nominally suppressed within the amplifying metasurface. A specially designed output coupler mirror is used such that large numbers of modes have nearly identical lasing thresholds. Up to nine lasing modes with a FSR of approximately 21 GHz are demonstrated – a significant increase from previous QC-VECSELs in which only 2 or 3 modes have been observed to lase at once. This work is an intermediate step towards eventually demonstrating THz QC-VECSELs as broadband incoherent emitters or frequency combs.
Session 8: Mid-IR Lasers and Integrated Systems
Session Chair: Miriam S. Vitiello, Istituto Nanoscienze (Italy)
Author(s): Leon Shterengas, Ruiyan Liu, Gela Kipshidze, Stony Brook Univ. (United States); Aaron Stein, Brookhaven National Lab. (United States); Wonjae Lee, Stony Brook Univ. (United States); Dmitri N. Zakharov, Kim Kisslinger, Brookhaven National Lab. (United States); Gregory Belenky, Stony Brook Univ. (United States)
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Photonic crystal surface emitting lasers emitting up to 2.6 µm have been designed and fabricated. A high-index-contrast photonic crystal layer was incorporated into the laser heterostructure by air-hole-retaining epitaxial regrowth. Transmission electron microscopy studies demonstrated uniform and continuous regrowth of the nano-patterned GaSb surface with AlGaAsSb alloy until air-pockets start being formed. The photonic crystal surface emitting lasers based on diode laser and cascade diode laser heterostructures generated narrow spectrum low divergence beams with mW-level output power. The angle-resolved electroluminescence analysis demonstrated well resolved photonic subbands corresponding to Γ2 point of square lattice and photonic gaps of several meV.
Author(s): Etienne Giraud, Pierre Demolon, Tobias Gresch, Loïc Urio, Antoine Müller, Richard Maulini, Alpes Lasers SA (Switzerland)
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We report wide tuning of external cavity interband cascade lasers (EC-ICLs) in continuous-wave operation at room temperature. The antireflection coated ICL gain chips were tuned with a diffraction grating in the Littrow configuration. A tuning of range of 313 cm-1 (360 nm) from 2789 cm-1 to 3102 cm-1 (3.22 to 3.58 μm) in continuous wave at 20oC was demonstrated with a 5 μm-wide, 1.5 mm-long gain chip. A maximum output power of 13 mW and a minimum threshold current of 62 mA were measured at the peak gain. The heat dissipation of the chip was 0.2 W at threshold and 0.8 W at the maximum current of 200 mA.
Author(s): Hedwig Knötig, Technische Univ. Wien (Austria); Robert Weih, nanoplus Nanosystems and Technologies GmbH (Germany); Nikola Opacak, Technische Univ. Wien (Austria); Johannes Koeth, nanoplus Nanosystems and Technologies GmbH (Germany); Gottfried Strasser, Benedikt Schwarz, Technische Univ. Wien (Austria)
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We present our recent results on the impact of intersubband absorption in the valence band on the performance of interband cascade lasers (ICLs). We observe a clear performance dependence on the thickness and composition of the Ga_(1-x) In_x Sb hole-quantum well (QW), reflecting in the characteristic temperature T_0 and the threshold current density J_(th). By carefully adjusting the design of the active W-QW the intersubband absorption in the valence band can be tailored and even completely avoided, allowing us to enhance ICL performance outside of the sweet spot 3-4 μm region, paving the way towards higher cw operating temperatures and output powers.
Author(s): Andres Remis, Institut d'Électronique et des Systèmes, Univ. de Montpellier (France); Laura Monge, Institut d'Électronique et des Systèmes, Univ. de Montpellier (France); Guilhem Boissier, Jean-Baptiste Rodriguez, Laurent Cerutti, Eric Tournié, Institut d'Électronique et des Systèmes, Univ. de Montpellier (France)
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The integration on silicon of light sources emitting in the 2-5 µm wavelength range for sensing applications is currently under the focus of attention. In this work we have studied the influence of the quantum well number (from 1 to 4 QWs) on the performances of GaSb-based laser diodes grown on silicon and emitting at 2.3 µm. We have observed that – somewhat counterintuitively – the best performances in terms of threshold current and internal losses are achieved with 1 QW. The results will be discussed in comparison with similar laser diodes grown on native GaSb substrates.
Author(s): Georg Marschick, Mauro David, Technische Univ. Wien (Austria); Alexandre Delga, III-V Lab. (France); Nikola Opacak, Benedikt Schwarz, Technische Univ. Wien (Austria); Mathurin Lagree, Thomas Poletti, Axel Evirgen, Bruno P. Gerard, III-V Lab. (France); Gottfried Strasser, Borislav Hinkov, Technische Univ. Wien (Austria)
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We present a novel InGaAs/InAlAs/InP quantum cascade detector (QCD) operating in the long wave infrared (LWIR) range, crucial for the exploitation of new free-space optical telecommunication channels at wavelengths between 8-12 µm. The comparison of differently sized detector ridges, processed on substrates with a 15-period as well as a single-period design, allows a characterization of the spectral photocurrent and a comparison of their performance in terms of sensitivity, spectral responsivity, detector noise etc. The goal is to distinguish design guidelines for the best candidate to establish a monolithic-integrated heterodyne detection system, able to secure high-speed and low-noise free-space data transmission.
In person: 26 January 2022 • 6:00 PM - 8:00 PM PST
Conference attendees are invited to attend the OPTO poster session on Wednesday evening. Come view the posters, enjoy light refreshments, ask questions, and network with colleagues in your field.

Poster Setup: Wednesday 10:00 AM – 5:00 PM
View poster presentation guidelines and set-up instructions at
Author(s): Rei Hashimoto, Kei Kaneko, Tsutomu Kakuno, Shinji Saito, Toshiba Corp. (Japan); Yuanzhao Yao, Naoki Ikeda, Yoshimasa Sugimoto, Takaaki Mano, Takashi Kuroda, Kazuaki Sakoda, National Institute for Materials Science (Japan)
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Surface emitting quantum cascade lasers (QCLs) are the attractive mid-infrared light source candidates for many laser-based applications. The vertical cavity surface-emitting laser structure cannot be applied to QCLs in principle, therefore using photonic crystals (PCs) is the remarkable solution to enable precise control of light behavior, such as wavelength selection and light extraction angle. Since the PCs are formed by lithography and dry etching, there is a difference between the design value and the finished dimensions. We observed the finished dimensions of InGaAs PCs after InP buried process, and evaluated the deviation from the design value.
Author(s): Maryam Dezfuli, Freddie Castillo, Weida Zhang, Scott McWilliams, Jerome K. Butler, Southern Methodist Univ. (United States); Ralph Johnson, Photon Sciences Inc. (United States); Nai-Hsiang Sun, I-Shou Univ. (Taiwan); Gary A. Evans, Southern Methodist Univ. (United States)
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Enhanced Coupling Strength (ECS) outcoupler gratings theoretically provide an order of magnitude reduction of grating length compared with conventional outcoupler gratings in III-V photonic waveguides. The dependence of the magnitude and spectral width of the outcoupled power of ECS outcoupling gratings is analyzed using a Floquet-Bloch space-harmonic approach for two different ECS grating geometries. ECS outcoupler gratings allow near-surface normal emission of integrated optical devices such as laser transmitters consisting of short horizontal cavity lasers combined with high-speed modulators that can operate without temperature control over a wide temperature and wavelength ranges.
Session 9: High Brightness
Session Chair: Gary M. Smith, MIT Lincoln Lab. (United States)
Author(s): Seval Arslan, Hans Wenzel, Jörg Fricke, Andreas Thies, Arnim Ginolas, Christoph Stölmacker, Andre Maassdorf, Bernd Eppich, Ferdinand-Braun-Institut (Germany); Rebecca B. Swertfeger, Susant K. Patra, Robert J. Deri, Matthew C. Boiselle, David L. Pope, Lawrence Livermore National Lab. (United States); Paul O. Leisher, Lawrence Livermore National Lab. (United States), Freedom Photonics LLC (United States); Günther Tränkle, Paul A. Crump, Ferdinand-Braun-Institut (Germany)
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High-power diode lasers use long resonators and asymmetric facet reflectivities, leading to longitudinally varying photon density (recombination rate) and early power saturation due to spatial-hole-burning. We summarize recent experimental studies into the relation between device geometry and local current and carrier densities to high powers (10W per 90µm stripe) and compare these to simulation. We use custom devices with segmented contacts (local current density) or back-side window (carrier density and temperature). Strong non-uniformity is observed that increases with bias, above prediction. Local heating at the front facet induces non-saturating carrier accumulation at the stripe edges, a key source of non-uniformity.
Author(s): Susumu Noda, Shumpei Katsuno, Masahiro Yoshida, Koki Izumi, Menaka De Zoysa, Kenji Ishizaki, Takuya Inoue, Kyoto Univ. (Japan)
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Photonic-crystal surface-emitting lasers (PCSELs) are an unprecedented type of semiconductor laser that have the potential of operating in a single longitudinal and lateral mode over a broad area. Recently, we achieved 10-W continuous wave (CW), high-beam-quality (M2~2) operation using a single-chip PCSEL with a circular resonator diameter of 1 mm. Very recently, we have succeeded in further increase of the output power to ~30W under CW condition by constructing a single chip PCSEL with a circular resonator diameter of 2 mm. In this conference, we will review such rapid progress of PCSELs.
Author(s): Philipp Hildenstein, Ferdinand-Braun-Institut (Germany)
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Tapered diode amplifiers feature an intrinsic astigmatism for vertical and horizontal beam axis. Additionally, the magnitude of astigmatism changes for different device working points. This work investigates the optical behaviour of tapered diode structures at different states of operation by means of an advanced theoretical model. It focuses on devices at an emission wavelength of 980 nm and a tapered section length of 4 mm. The theoretical model is based on a beam propagation method which is coupled to a thermal and an electrical model. The simulation outcomes are necessary for an advanced understanding of experimental outcomes.
Author(s): Bernd Sumpf, Lara Sophie Theurer, Martin Maiwald, André Müller, André Maaßdorf, Jörg Fricke, Peter Ressel, Günther Tränkle, Ferdinand-Braun-Institut (Germany)
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4 mm long DBR tapered diode lasers at 785 nm with three different lateral layouts will be presented. The devices consist of an unpumped DBR section, a ridge waveguide section, and a tapered section with a full taper angle of 6°. The impact of different lengths of the 10th order surface DBR gratings on the spectral behavior and the beam parameters at different RW currents will presented. With the best layout, the devices reach up to 7 W of optical output power together with a narrow spectral width smaller than 19 pm and a beam parameter M2 below 3 (1/e2 level).
Session 10: Mid-IR QCLs: Modeling and New Architectures
Session Chair: Hedwig M. Knötig, Technische Univ. Wien (Austria)
Author(s): Irena Knezevic, Univ. of Wisconsin-Madison (United States)
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We present a quantum-mechanical model for photon-driven transport in QCLs that is computationally inexpensive, requires no phenomenological parameters, and is conducive to intuition building. The model stems from a rigorous theoretical framework with a positivity-preserving Markovian master equation of motion for the density matrix. The equation of motion is solved self-consistently and nonperturbatively, and used to compute the steady-state and frequency response of a previously published midinfrared QCL. Our results show how PA tunneling alters electron transport around and above lasing threshold, and explain why the changes are pronounced in diagonal QCLs. With the inclusion of PA tunneling, the calculated curves for current density versus field and output power versus current density are in close agreement with experiment.
Author(s): Suraj Suri, Benjamin Knipfer, Jeremy D. Kirch, Luke J. Mawst, Univ. of Wisconsin-Madison (United States); Thomas Grange, nextnano GmbH (France); Dan Botez, Univ. of Wisconsin-Madison (United States)
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Accurate simulation of V-I characteristics for mid-IR quantum cascade lasers (QCLs) with photon-induced carrier transport (PICT) is achieved by using the non-equilibrium Green’s function method coupled with the interface-roughness scattering formalism taking into account graded interfaces and axial correlation lengths. Analysis of 4.9 µm- and 8.3 µm-emitting, buried-heterostructure (BH) QCLs reveals that PICT action reduces the differential resistance by a factor of 2.5 and increases the maximum-current density by ~ 30 % compared to conventional BH QCLs, which explains their record-high, single-facet wall-plug efficiency values (i.e., 27 % and 17 %). Interface grading allows obtaining emission wavelengths close to experiment.
Author(s): Shinji Saito, Rei Hashimoto, Kei Kaneko, Tsutomu Kakuno, Shinji Ookuma, Ryuichi Togawa, Toshiba Corp. (Japan); Yuanzhao Yao, Naoki Ikeda, Yoshimasa Sugimoto, Takashi Kuroda, National Institute for Materials Science (Japan); Hirotaka Tanimura, Shigeyuki Takagi, Tokyo Univ. of Technology (Japan); Kazuaki Sakoda, National Institute for Materials Science (Japan)
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We report on the surface emitting quantum cascade lasers (QCL) using a two-dimensional photonic crystal (PC) at 4μm. The quantum well of the light-emitting layer was a strain-compensated system, and the crystal regrowth for buried PC was achieved while maintaining the crystal quality under thermal budgets of high-temperature regrowth. PC-QCLs lasing was realized on the single-mode vertical-emission at 77K under pulse operation. The threshold current density is 760 A/cm2. The far-field radiation pattern showed a very small divergence angle of less than 2°
Author(s): Mikolaj Janczak, Robert P. Sarzała, Włodzimierz Nakwaski, Tomasz G. Czyszanowski, Lodz Univ. of Technology (Poland)
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Quantum-cascade lasers (QCL) enable emission in a broad range of infrared radiation unavailable for convectional quantum well bipolar lasers. However in-plane geometry of QCLs hinders achieving properties required in numerous applications which are inherently possessed by vertical-cavity surface-emitting lasers (VCSELs). In proposed design of QC-VCSEL the role of top mirror and element inducing component of electric field necessary to stimulated emission in quantum cascades is served by subwavelength monolithic high-refractive-index contrast grating (MHCG) in which quantum cascade active region is embedded. This paper based on numerical analysis presents influence of QC-VCSELs configuration details on threshold currents and mode distributions.
Session 11: Mid-IR QCLs and Applications
Session Chair: Kevin M. Oresick, DRS Daylight Solutions (United States)
Author(s): Kevin Lascola, Thorlabs Quantum Electronics (United States)
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Quantum Cascade Lasers (QCLs) are an ideal light source for many mid-infrared applications due their high power, small size and the ability to customize the output wavelength through quantum engineering, rather than material composition. For most applications, high output power and high efficiency should be achieved without compromising other key characteristics, such as beam quality, spectral brightness or reliability. These goals are often in conflict and this presentation will emphasize the production process control as well as engineering design choices that enable us to demonstrate reliable watt-level output powers across the mid-infrared.
Author(s): Borislav Hinkov, Florian Pilat, Laurin Lux, Technische Univ. Wien (Austria); Patricia L. Souza, Pontifical Catholic Univ. of Rio de Janeiro (Brazil); Andreas Schwaighofer, Benedikt Schwarz, Hermann Detz, Aaron M. Andrews, Technische Univ. Wien (Austria); Bettina Baumgartner, Utrecht Univ. (Netherlands); Bernhard Lendl, Gottfried Strasser, Technische Univ. Wien (Austria)
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In this work we monolithically integrate a quantum cascade laser (QCL) and detector (QCD) addressing the same wavelengths lambda=1550-1650 cm-1 for liquid spectroscopy. QCL and QCD are combined using a 50-100 µm-long dielectric-loaded surface-plasmon-polariton (DLSPP) waveguide, which typically guides >>90% of the mode outside of the cavity. We show the analysis of the protein bovine serum albumin (BSA) and its denaturation process between 25°C-90°C in real time in a microfluidic cell (60 µl) for 20-60 mg/ml BSA-concentrations. To further test the sensor-robustness, we directly submerge it into a beaker and detect H2O up to 35%-40%, solved in isopropyl alcohol.
Author(s): Pierre Didier, Télécom Paris (France); Ke Yang, Institute of Semiconductors, Chinese Academy of Sciences (China); Olivier Spitz, Alice Guillaume-Manca, Télécom Paris (France); Junqi Liu, Institute of Semiconductors, Chinese Academy of Sciences (China); Frédéric Grillot, Télécom Paris (France)
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Long-wave infrared communication systems are poised to become one of the key wireless technologies in order to extend the current communication network, especially in areas where fiber deployment is rather difficult and expensive or when the emitter and receiver need to be mobile. We demonstrate a high-speed data transmission with a room-temperature quantum cascade laser emitting at 8.1 µm. The maximum data rate we can achieve is above 1 Gbits/s and allows broadcasting an uncompressed high-definition video on a remote screen. This proof-of-concept experiment is promising for long-distance free-space transmission because long-wave infrared wavelengths are almost immune to weather perturbations.
Author(s): Andrea Zifarelli, Raffaele De Palo, Pietro Patimisco, Marilena Giglio, Angelo Sampaolo, Univ. degli Studi di Bari Aldo Moro (Italy); Stéphane Blaser, Tobias Gresch, Olivier Landry, Antoine Müller, Alpes Lasers SA (Switzerland); Frank K. Tittel, Rice Univ. (United States); Vincenzo Spagnolo, Politecnico di Bari (Italy)
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Here we report on the multi-gas detection of carbon monoxide (CO), nitrous oxide (N2O), carbon dioxide (CO2), and water vapor (H2O) by using a quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor exploiting a Vernier-effect distributed-feedback quantum cascade laser as excitation source. This innovative laser behaves as a switchable, multi-color, electrically tunable light source with an extended tuning range, ranging from 2100 cm-1 to 2220 cm-1. The achieved detection limits were 4 ppb, 7 ppb, and 71.8 ppm for CO, N2O, and CO2, respectively, at 100 ms of integration time. Finally, QEPAS sensor was tested with laboratory air samples for two days.
Author(s): Mauro David, Alicja Dabrowska, Masiar Sistani, Technische Univ. Wien (Austria); Erik Hinkelmann, Brno Univ. of Technology (Czech Republic); Ismael C. Doganlar, Hermann Detz, Walter M. Weber, Bernhard Lendl, Gottfried Strasser, Borislav Hinkov, Technische Univ. Wien (Austria)
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Semiconductor-loaded plasmonic (SLSPP)-waveguides are a very efficient link for optoelectronic devices, facilitating miniaturized photonic integrated circuits. However, for long-wave infrared applications (8-12 µm), the material selection is challenging as most commonly used mid-IR materials absorb in this region. Therefore, we selected and investigated the properties of germanium in a hybrid semiconductor-metal-configuration to overcome these limitations. The experimental characterization of Si(substrate)-Au-Ge fabricated SLSPP-waveguides show very good agreement with FEM-simulations. Moreover, the realized devices offer low losses between 8.8 and 22 dB/mm (single device) and even within 8.8-15 dB/mm (multiple devices), respectively, for the entire investigated octave-spanning 5.6 – 11.2 µm range.
Conference Chair
Texas A&M Univ. (United States)
Conference Chair
Cardiff Univ. (United Kingdom)
Program Committee
Yasuhiko Arakawa
The Univ. of Tokyo (Japan)
Program Committee
Technische Univ. München (Germany)
Program Committee
Dan Botez
Univ. of Wisconsin-Madison (United States)
Program Committee
Harvard John A. Paulson School of Engineering and Applied Sciences (United States)
Program Committee
Gary A. Evans
Southern Methodist Univ. (United States)
Program Committee
Politecnico di Torino (Italy)
Program Committee
Technische Univ. Berlin (Germany)
Program Committee
Microsoft Research Cambridge (United Kingdom)
Program Committee
Kei-May Lau
Hong Kong Univ. of Science and Technology (Hong Kong, China)
Program Committee
Virginia Polytechnic Institute and State Univ. (United States)
Program Committee
NTT Device Technology Labs. (Japan)
Program Committee
Univ. of Wisconsin-Madison (United States)
Program Committee
U.S. Naval Research Lab. (United States)
Program Committee
Boston Univ. (United States)
Program Committee
Ferdinand-Braun-Institut (Germany)
Program Committee
Univ. of Cambridge (United Kingdom)
Program Committee
Johann Peter Reithmaier
Univ. Kassel (Germany)
Program Committee
Intel Corp. (United States)
Program Committee
MIT Lincoln Lab. (United States)
Program Committee
Nelson Tansu
The Univ. of Adelaide (Australia)
Program Committee
Istituto Nanoscienze (Italy)
Program Committee
Nanyang Technological Univ. (Singapore)
Program Committee
Wanhua Zheng
Institute of Semiconductors, Chinese Academy of Sciences (China)