Show all abstracts
View Session
- Front Matter: Volume 7941
- Waveguide Engineering I
- Amplifiers and Lasers
- Photonic Integration
- Modelling and Design
- Sensors I
- Sensors II
- Waveguide Engineering II
- Plasmonic
- Subwavelength/Diffractive Photonics
- Poster Session
Front Matter: Volume 7941
Front Matter: Volume 7941
Show abstract
This PDF file contains the front matter associated with SPIE Proceedings Volume 7941, including the Title Page, Copyright Information, Table of Contents, Conference Committee listing, and Introduction.
Waveguide Engineering I
Large-scale planar lightwave circuits
Show abstract
By leveraging advanced wafer processing and flip-chip bonding techniques, we have succeeded in hybrid integrating a
myriad of active optical components, including photodetectors and laser diodes, with our planar lightwave circuit (PLC)
platform. We have combined hybrid integration of active components with monolithic integration of other critical
functions, such as diffraction gratings, on-chip mirrors, mode-converters, and thermo-optic elements. Further process
development has led to the integration of polarization controlling functionality. Most recently, all these technological
advancements have been combined to create large-scale planar lightwave circuits that comprise hundreds of optical
elements integrated on chips less than a square inch in size.
Characterization of irradiance effects on curing of siloxane for embedded waveguide applications
Show abstract
In order to maintain the overall optical performance in a step index rectangular waveguide, the complex index of
refraction of the core and cladding material must be maintained throughout the cycle of the lithographic fabrication
process. The percentage of the core and cladding material that is cured and the irradiance that cure took place directly
affects the complex index of refraction of these materials. Siloxanes produced by Dow Corning have been selected to
meet the requirements for embedded waveguides for circuit board applications due to their optical performance
characteristics and their compatibility with current manufacturing techniques. The required total dose for a 50 μm thick
layer of siloxane is 1200 mJ at an irradiance of 30 mW/cm2. In order to utilize lower irradiance levels the total dose of
the ultraviolet exposure must be characterized and calibrated. By measuring the changes in the absorption peaks of the
materials using transmission data from ellipsometric techniques it is possible to define the percentage cure of the
siloxane from different curing profiles. Ellipsometric techniques were also utilized to measure the complex refractive
index of the materials cured using different profiles. It was found that the total dose required for a complete cure and the
complex refractive index of these materials drastically changes with different irradiances and the profile for the total
dose compared to the curing of the siloxane materials at all irradiances is logarithmic.
Monolithic integration of chalcogenide glass/iron garnet waveguides and resonators for on-chip nonreciprocal photonic devices
Show abstract
We report monolithic integration of chalcogenide glass(ChG)/iron garnet waveguides and racetrack resonators on silicon
for on-chip nonreciprocal photonic devices applications. Using a two step growth strategy, we successfully integrated
phase pure Bi0.8Y2.2Fe5O12 (Bi0.8YIG), Bi1.8Y1.2Fe5O12 (Bi1.8YIG) and Ce1Y2Fe5O12 (CeYIG) polycrystalline thin films
on silicon with low fabrication thermal budgets. Strip-loaded ChG/Iron garnet waveguides and racetrack resonators were
fabricated by thermal evaporation and lift off. The waveguide loss was systematically characterized by cutback and
paperclip methods. For the first time, the optical transmission loss of polycrystalline Bi or Ce doped garnets were
evaluated at communication wavelengths in waveguides. Polycrystalline CeYIG films show a saturation Faraday rotation
of -830deg/cm and transmission loss of ~40dB/cm at 1550nm, which is promising for on-chip nonreciprocal photonic
device applications. Such waveguide structures were successfully incorporated in GeS2/Bi0.8YIG racetrack resonators
which show well defined resonance spectrum at near infrared wavelength. The nonreciprocal phase shift (NRPS) and
device figure of merit of the ChG/Garnet waveguides were simulated by numerical methods. Possible improvements and
applications of such devices for integrated optical isolator applications are analyzed and discussed.
Fully compatible magneto-optical sol-gel material with glass waveguides technologies: application to mode converters
Show abstract
To overcome the difficult problem of the integration of magneto-optical materials with classical technologies, our group
has developped a composite magneto-optical material made of a hybrid organic-inorganic silica type matrix doped by
magnetic nanoparticles. Thin films of this material are obtained through a soft chemistry sol-gel process which gives a
full compatibility with an integration on glass substarte. Due to an interesting magneto optical activity (Faraday rotation
of 310°/cm) several magneto-optical functionnalities have been realized. A thin film of such composite material coated
on a pyrex™ substrate acts as non-reciprocal TE/TM mode converter. An hybrid stucture made of a composite film
coated on an ion-exchanged glass waveguide has been realized with a good propagation of light through a hybrid mode.
Finally, the sol gel process has been adapted in order to obtain 3D inverse opals which should behave as magnetophotonic
crystals. Transmittance curves reveal the photonic band gap of such opals doped with magnetic nanoparticles.
Amplifiers and Lasers
Synthesis and tailoring of CdSe core@shell heterostructures for optical applications
Show abstract
The successive ion layer deposition reaction (SILAR) technique has been applied to CdSe based systems to develop
Type 1 heterostructures . In such structures, the CdSe core is covered by wider band gap semicondutors to improve the
emission properties. Cores of different dimensions has been synthesised and two different shell structures have been
addressed.
The obtained particles have been characterised by TEM technique, while UV-Vis absorption and photoemission
spectroscopy were used to characterise the optical properties of the particles in the colloidal solution.
The obtained particles were also introduced in a ZrO2 sol-gel matrix to fabricate photoluminescent waveguides, which
were characterised also by spectroscopic ellipsometry.
Integrated optics dissipative soliton mode-locked laser on glass
Show abstract
Mode-lock lasers have been studied a lot in the past years for producing pulses as short as possible. These
devices have mostly been realized in bulk optics and they are consequently cumbersome and sensitive to
vibrations. There are only a few studies on integrated optics mode-lock lasers, though this technology is very
promising because of its stability, compactness and the possibility to integrate several functions on a single chip.
In this paper, we present an ion-exchange passively mode-locked laser in dissipative soliton operation. One of
the key characteristics of this structure is its mechanical stability. Indeed, no bulk optics is needed because the
saturable absorber is hybridized on the top of the waveguide in order to interact with the evanescent part of the
guided mode. Indeed, the device that has been obtained is composed of an ion-exchanged single mode
waveguide realized in a Neodymium doped phosphate glass. The laser feedback is produced by a Fabry-Perot
cavity realized with two multilayers dielectric mirrors stuck on the waveguides facets. We implemented a bis(4-
dimethylaminodithiobenzil)nickel (BDN) dye included in a cellulose acetate thick film, which presents a
saturable absorber behaviour around 1.06 μm. With this structure, pulses with repetition rates of 3.3 GHz and a
single mode output have been measured. Moreover, the use of an autocorrelation set-up allowed us measuring
picosecond pulse durations.
Photonic Integration
Hybrid photonic integrated circuits for faster and greener optical communication networks
Show abstract
We present current development efforts on hybrid photonic integration for new generation "faster and greener" Tb/scapacity
optical networks. On the physical layer, we present the development of a versatile, silicon-based photonic
integration platform that acts as a technology "blender" bringing together different material systems including III-V and
silicon-based semiconductors. The platform is also used to implement the so-called O-to-O (optical-to-optical)
functionalities by patterning low-loss passive components such as MMI couplers and delay interferometers. With these
passive building blocks as well as the ability for hybrid assembly of active material, we demonstrate the fabrication of
key optical transport and routing devices such as optical demodulators and all-optical wavelength converters. These
devices can now be used to fabricate chip-scale 100 GbE transceiver PICs and Tb/s-capacity wavelength switching
platforms.
Light-bullet routing and logic in planar waveguide arrays
Show abstract
The manipulation and routing of light-bullets in a VCSEL-like planar waveguide array is studied numerically. By
partitioning the gold contact layer used for current injection into discrete and individually addressable segments,
an electronically controllable and non-uniform gain profile is created. Light-bullets typically follow the gradient
of the gain and are therefore completely controllable by manipulating the gain profile. In addition, by exploiting
gain-mediated interactions between nearby light-bullets, the NAND and NOR gates are also constructed. Therefore,
planar waveguide arrays with addressable gain profiles appear to be an ideal technology for optical routing
applications as well as for photonic logic devices.
Modelling and Design
Fast online simulation of 3D nanophotonic structures by the reduced basis method
Show abstract
We present algorithmic details and applications of the reduced basis method as efficient Maxwell solver to
nanophotonic applications including examples from mask optimization in photolithography and parameter retrieval
in inverse problems, e.g., in optical metrology. The reduced basis method is a currently studied approach
to the multiple solution of problems depending on a number of geometrical, material and source parameters.
Such problems occur frequently in optimization tasks where parameters have to be adjusted in order to minimize
some error functionals or in production environments where deviations from ideal structures have to be
controlled.
Far field scattering by a waveguide-coupled nanowire
Show abstract
We study both experimentally and numerically far-field radiation patterns of single metallic nanowires coupled
to weak confined optical waveguides. The radiation pattern resulting from the interaction of the nanowire and
the optical mode depends strongly on the mode properties (polarization and wavenumber) and on the antenna
properties (material and size). To investigate these phenomena we compare the electric far-field distributions
computed with different numerical methods (Green's tensor technique, rigourous coupled wave method, Fourier
modal method). We also compare simulated results to experimental measurements obtained over a large spectral
domain ranging from 400 nm to 1000 nm. This study should be useful for optimizing nanostructured photonic
circuits elements.
Sensors I
Photonic crystal slot waveguide spectrometer for the detection of methane
Show abstract
Defect engineered photonic crystals, with sub-micron dimensions have demonstrated high sensitivity to trace volumes of
analytes; however exact identification of analyte through spectroscopic signatures had not been demonstrated. We
demonstrate a 300micron long photonic crystal slot waveguide device which combines slow light phenomenon in
photonic crystal waveguides with large optical field intensity in a low index narrow slot at the center of the photonic
crystal waveguide for highly sensitive spectroscopic detection of methane on-chip at 100 parts per million (ppm) or
0.2% permissible exposure limit. Photonic crystal slot waveguide provides a factor of 1000 reduction in interaction
length compared to free-space infrared spectroscopy leading to enhanced optical absorption by analytes in the optical
path. By measuring absorption differences in presence and absence of methane, near-infrared absorption spectrum of
methane is determined.
Optimization of waveguide structure for local evanescent field shift detection
Show abstract
The waveguide structure for the local evanescent array coupled (LEAC) biosensor is optimized theoretically
with Beam Propagation Method (BPM) simulations. The LEAC biosensor has successfully demonstrated
experimental results of a sensitivity of 16% /nm and a metrology limit of 14 pm. Considering the waveguide
thickness detector position used in previous experiments are far from optimized values, the detection performance of
the LEAC sensor can be significantly improved with the simulated optimal structure. With the optimized
parameters, when the upper cladding is air the estimated metrology limit is 0.8 pm; with water as the upper cladding
for real-time measurements in an intigrated microfluidic channel, the estimated metrology limit is 1.6 pm.
Carbon nanotubes coated fiber optic ammonia gas sensor
Show abstract
We report, intrinsic fiber optic carbon nanotubes coated sensor for the detection of ammonia gas at room temperature.
Multimode step index polymethyl methacrylate (PMMA) optical fiber passive cladding is partly replaced by an active
coating of single and multi-walled carbon nanotubes following the dip coating technique and the reaction with ammonia
is studied by measuring the change in output intensity from the optical fiber under various ammonia gas concentrations
in the range 0-500 ppm in step of 50 ppm. The sensitivity is calculated for different wavelengths in the range 200-1100
nm both for single and multi-walled carbon nanotubes coated fiber. Higher sensitivities are obtained as 0.26 counts/ppm
and 0.31 counts/ppm for single-walled (average diameter 1.3 nm, 30 wt.% purity) and multi-walled (average diameter
10-15 nm, 95 wt.% purity) carbon nanotubes respectively. The role of diameter and purity of carbon nanotubes towards
the ammonia sensing is studied and the results are discussed.
Sensors II
Hydrogen absorption effects on the transmittance of sub-wavelength palladium hole arrays with different thicknesses
Etsuo Maeda,
Sho Mikuriya,
Ichiro Yamada,
et al.
Show abstract
The far-field extraordinary optical transmission (EOT) of palladium (Pd) sub-wavelength hole arrays in the infrared
region is used to detect hydrogen near the lower flammability threshold in air. Upon exposure to hydrogen, the Pd layer
of the hole array expands, causing changes in the hole structure, and the Pd permittivity decreases. These two effects
shift the main EOT transmittance peak of the Pd hole array to longer wavelengths. In this report, the effect of the Pd
layer thickness on the redshift is analyzed by the rigorous coupled wave analysis technique and experimental observation.
Our computational and experimental results show that the hole structural effect on the peak shift is dominant in the
opaque region of the Pd layer transmission, whereas the Pd permittivity effect is dominant in the semi-transparent region.
The optimum Pd layer thickness for hydrogen sensing is found to be at the boundary between the semi-transparent and
the opaque regions of the Pd layer.
Consideration of sensitivity with respect to diaphragm thickness and waveguide position in silicon-based guided-wave optical accelerometer
Yusuke Miura,
Hideto Endo,
Takuya Oshima,
et al.
Show abstract
Our group has developed a silicon-based guided-wave optical accelerometer with a proof mass centered on a diaphragm.
For this type of accelerometer, it is strongly suggested that sensitivity is related to waveguide position, diaphragm
dimensions, and size and weight of proof mass. In this study, sensitivity dependences on waveguide position and
diaphragm thickness were considered experimentally. Experimental results demonstrated that the highest sensitivity
could be obtained for the waveguide at the diaphragm edge and is inversely proportional to the square of the diaphragm
thickness.
Waveguide Engineering II
New tracks toward 3D light harnessing: high Q slow Bloch mode engineering and coupling to 0D nanophotonic structures
Show abstract
We will show in this paper that a new approach combining Photonic crystal (PC) and nano-antennas (NA's) allows for an efficient addressing of NA using a wide Gaussian beam. First, we will present results from a phenomenological approach (coupled mode theory in the time domain) of this mixed device. We derive the key factors that govern the coupling processes and show that high Q PC structures are required for efficient coupling. The design rules for high Q PC structures providing resonant slow Bloch modes above the light line are presented, on the basis of FDTD simulation results. We will end the presentation with FDTD simulations of the mixed structure (PC+NA), confirming the prediction of the coupled mode theory. Preliminary technological realization will be presented, together with a discussion on potential applications for optical trapping.
GaAs-SOI integration as a path to low-cost optical interconnects
Show abstract
We present a concept where GaAs chips with dilute nitride and quantum dot optoelectronics are hybrid integrated on a
silicon-on-insulator (SOI) waveguide platform and packaged into low-cost modules using silicon as the packaging
material. The approach aims to offer high energy efficiency, low cost and high bandwidth for optical interconnects
operating at 1.2-1.3 μm wavelengths. It presents technologies that could bridge the gap between long and short range
optical communication, which are presently based on incompatible wavelength ranges and waveguiding technologies
(single vs. multimode).
Coupling of lithium niobate disk resonators to integrated waveguides
Show abstract
Whispering gallery mode (WGM) disk resonators fabricated in single crystals can have high Q factors within their
transparency bandwidth and may have application both in fundamental and applied optics. Lithium niobate (LN)
resonators thanks to their electro-optical properties may be used in particular as tunable filters, modulators, and delay
lines. A critical step toward the actual application of these devices is the implementation of a robust and efficient
coupling system. High index prisms are typically used for this purpose. In this work we demonstrate coupling to high-Q
WGM LN disks from an integrated optical LN waveguide. The waveguides are made by proton exchange in X-cut LN.
The disks with diameters of about 5 mm and thickness of 1 mm are made from commercial Z-cut LN wafers by core
drilling a cylinder and thereafter polishing the edges into a spheroidal profile. Both resonance linewidth and cavity
photon lifetime measurements were performed to calculate the Q factor of the resonator, which is in excess of 108.
Plasmonic
Rigorous characterization of surface plasmon modes by using the finite element method
Show abstract
Vectorial modal field profiles and the complex propagation characteristics of Surface Plasmon modes in optical and THz
guided wave structures are presented by using a H-field based finite element method. It is shown here that by
engineering the metal electrode mode selectivity in a Quantum cascade laser can be enhanced. Additionally, it is also
shown that by introducing Teflon coating, the propagation loss of a hollow-core rectangular waveguide can be
significantly reduced.
Plasmon-induced transparency in subwavelength metal-dielectric-metal waveguides
Show abstract
Plasmonic devices, based on surface plasmons propagating at metal-dielectric interfaces, have shown the potential to
guide and manipulate light at deep subwavelength scales. In addition, slowing down light in plasmonic waveguides leads
to enhanced light-matter interaction, and could therefore enhance the performance of nanoscale plasmonic devices such
as switches and sensors. In this paper, we introduce slow-light subwavelength plasmonic waveguides based on a
plasmonic analogue of electromagnetically induced transparency (EIT). Both the operating wavelength range and the
slowdown factor of the waveguides are tunable. The structure consists of a periodic array of two metal-dielectric-metal
(MDM) stub resonators side-coupled to a MDM waveguide. The two cavities in each unit cell have a resonant frequency
separation which can be tuned by adjusting the cavity dimensions. We show that in the vicinity of the two cavity
resonant frequencies, the system supports three photonic bands, and the band diagram is similar to that of EIT systems.
The middle band corresponds to a mode with slow group velocity and zero group velocity dispersion in the middle of the
band. Decreasing the resonant frequency separation, increases the slowdown factor, and decreases the bandwidth of the
middle band. We also find that metal losses lead to a tradeoff between the slowdown factor and the propagation length of
the supported optical mode. We use a single-mode scattering matrix theory to account for the behavior of the
waveguides, and show that it is in excellent agreement with numerical results obtained with the finite-difference
frequency-domain method.
Linear and nonlinear resonant effects in metallic arrays of sub-wavelength channels filled with GaAs
Show abstract
We investigate on the interaction of surface plasmon modes with TEM, Fabry-Perot-like cavity modes in arrays of subwavelength
slits filled with GaAs. A full control on the transmission process, which is mostly dictated by the
geometrical parameters of the array, such as the slit length and width as well as the separation between the slits, is
achieved and explained. The effects of the interaction of pure cavity modes and surface modes lead to the formation of
an energy band gap, i.e. a spectral band where a drastic inhibition of transmission is induced by the coupling and backradiation
of the smooth-interface, unperturbed surface plasmon. Strong field localization in sub-wavelength regions
boosts also the nonlinear response of the structure. The mere assumption that the metal is nonlinear via Coulomb and
Lorentz contributions, and the introduction of high-index, nonlinear media, such as III-V semiconductors, in the subwavelength
channels opens a cross-coupling of TE and TM polarizations for both pump and harmonic signals and makes
it possible to generate both TE- and TM-polarized fields. These fields are generated even under high-absorption
conditions, and survive thanks to a phase locking mechanism that sets in between the pump and its harmonics.
Characteristics and applications of rectangular waveguide in sensing, slow light, and negative refraction
Show abstract
Rectangular waveguide is a very promising structure for different applications. It has some unique characteristics that
allow for wide range of application including slow and fast light, metamaterial, low loss energy transmission, and
sensing. The resemblances and differences between this waveguide configuration and metal-insulator-metal (MIM) are
discussed in this paper. A Description of the guided modes and their operating band is also given. We also studied the
characteristics of the fundamental TM-like mode of this structure for the first time. Its potential application in sensing
and low loss energy transporting is also demonstrated. The effect of the design parameters on the performance of the
rectangular waveguide is illustrated for different application. Slow light and negative refraction effects using this
waveguide design using TE-like mode is also demonstrated. Different designs are proposed using this structure for these
different applications. Square shape design allow for polarization insensitive applications which is one of the unique
characteristics of the configuration.
Subwavelength/Diffractive Photonics
Subwavelength and diffractive waveguide structures and their applications in nanophotonics and sensing
Show abstract
We review recent advances in subwavelength and diffractive structures in planar waveguides. First, we present a new
type of microphotonic waveguide, exploiting the subwavelength grating (SWG) effect. We demonstrate several
examples of subwavelength grating waveguides and components made of silicon, operating at telecom wavelengths. The
SWG technique allows for engineering of the refractive index of a waveguide core over a range as broad as 1.5-3.5
simply by lithographic patterning using only two materials, for example Si and SiO2. This circumvents an important
limitation in integrated optics, which is the fixed value of the refractive indices of the constituent materials in the absence
of an active tuning mechanism. A subwavelength grating fibre-chip microphotonic coupler is presented with a loss as
low as 0.9 dB and with minimal wavelength dependence over a broad wavelength range exceeding 200 nm. It is shown
that the SWG waveguides can be used to make efficient waveguide crossings with minimal loss and negligible crosstalk.
We also present a diffractive surface grating coupler with subwavelength nanostructure, that has been implemented in a
Si-wire evanescent field biological sensor. Furthermore, we discuss a new type of planar waveguide multiplexer with a
SWG engineered nanostructure, yielding an operation bandwidth exceeding 170 nm for a device size of only 160 μm ×
100 μm.
Long period and fiber Bragg gratings written within the same fiber for sensing purposes
Show abstract
Long period gratings (LPGs) have been recently proposed as sensing elements of chemical/biological compounds,
exploiting their sensitivity to the refractive index changes in the surrounding environment. One of the difficulties of their
utilization for this purpose is their strong dependence also to strain and temperature effects. An intrinsic optical feedback
able to eliminate these effects was developed by manufacturing on the same fiber the LPG and a fiber Bragg grating
(FBG) which is immune from external refractive index changes and is influenced by strain and temperature. An accurate
temperature measurement system is utilised to eliminate or in any case to reduce to a minimum the interferences coming
from temperature changes. A KrF excimer laser is used to write both the gratings into the same photosensitive fiber. The
period of the LPG and FBG gratings are 615 μm and 530 nm, respectively and the attenuation at their resonance
wavelengths (1570 nm for LPG and 1534 nm for FBG) was of the order of 15-20 dB. The same source, a broadband
superluminescent diode with emission peak at 1550 nm, is used to interrogate both the gratings. The transmission spectra
is acquired by means of an optical spectrum analyzer (OSA) controlled by a PC and an in-house software identifies the
attenuation band in the FBG and LPG transmission spectra and calculates the minimum values. A suitable thermostabilized
flow cell with a volume of 50 μL containing the fiber with the two gratings, has been developed and
characterized.
Pixelated resonant subwavelength grating filters for greenhouse gas monitoring
Show abstract
We describe the design of pixelated filter arrays for hyperspectral monitoring of CO2 and H2O absorption in the
midwave infrared (centered at 4.25μm and 5.15μm, respectively) using resonant subwavelength gratings (RSGs), also
called guided-mode resonant filters (GMRFs). For each gas, a hyperspectral filter array of very narrowband filters is
designed that spans the absorption band on a single substrate. A pixelated geometry allows for direct registration of
filter pixels to focal plane array (FPA) sensor pixels and for non-scanning data collection. The design process for
narrowband, low-sideband reflective and transmissive filters within fabrication limitations will be discussed.
High-sensitive nonlinear detection of steroids by resonant double grating waveguide structures-based immunosensors
Alejandro Muriano,
J.-Pablo Salvador,
Roger Galve,
et al.
Show abstract
We report the non linear fluorescence real-time detection of methylboldenone, an androgenic anabolic steroid used
illegally as growth promoter based on a resonant sensing chip: a double grating waveguide structure. The limit of
detection of this synthetic steroid is two orders of magnitude lower than the Minimum Required Performance Limit
required by the World Anti-Doping Agency. The immunoreagents have been have been immobilized onto the surface of
the resonant sensor after being activated with phosphonohexanoic acid spacers. The developed immunosensor presents
great potential as a robust sensing device for fast and early detection of illegal dopants and food contaminants.
Photonic nanojet engineering: focal point shaping with scattering phenomena of dielectric microspheres
Show abstract
We experimentally engineer Nanojets produced by dielectric spheres by varying the illumination and observe the effect
with a high-resolution interference microscope (HRIM). Converging and diverging spherical wavefronts and Bessel-
Gauss beams are considered. We find that the diverging wavefront pushes Nanojets away from the surface of the sphere
without change of the spot size. This allows earning several micrometers of working distance contrary to the Nanojet
confined at the sphere's surface. When the radius of curvature of the incident wavefront is greater than about 5 times the
sphere size, the Nanojet moves back to the sphere surface like it is found for plane wave incidence. On-axis Bessel-
Gauss beam illumination with the central lobe covering the whole sphere leads to the same results as the plane wave
case. Off-axis Bessel beam illumination can generate multiple-spot Nanojets. We demonstrate the separation of such
spots of about 220 nm at 642 nm. This separation is smaller than the feature sizes defined by the diffraction limit at this
wavelength. We discuss briefly applications of engineered Nanojets for nano-lithography and near-field sensing.
Poster Session
Waveguide integrated plasmonic platform for sensing and spectroscopy
Show abstract
We propose a waveguide integrated plasmonic platform in order to deliver excitation power to and collect signal
efficiently from a nanoantenna. The system consists of a silicon waveguide with an integrated nanoantenna and a fiber
spot size converter. The nanoantenna is designed to have a broad resonance around 1.5 microns with an estimated
surface enhanced Raman scattering (SERS) enhancement of 6 orders of magnitude and collection efficiency up to 80%.
The device is fabricated on a silicon-on-insulator (SOI) wafer. The proposed and fabricated device can be used in
applications such as on-chip SERS spectroscopy, infrared spectroscopy and gas sensing.
Analysis of surface plasmon resonance triangular-resonator sensor
Show abstract
In this paper, we propose an integrated photonic sensor structure using triangular ring resonator (TRR), in which
surface plasmon resonance (SPR) is combined for the enhancement of sensitivity. In our previous experimental work on
TRR without SPR, we have shown that the Q-factor and the sensitivity of the resonance shift were approximately 7×102and 8.4 nm/RIU, respectively, near 1550 nm. By employing a thin-metal layer for SPR at the total-internal-refection
mirror in TRR, we have obtained significantly enhanced sensitivity of the resonance shift up to 55 nm/RIU maintaining
similar Q-factor.
Enhanced light transmission through a metallic nanolens consisting of multiple nanorings
Show abstract
In this study, we investigated light transmission based on a metallic nano-lens for imaging applications. The nano-lens
consists of multiple nano-rings formed in a thin metal film. Four types of nano-lens structures in a 50-nm thick gold film
were simulated using rigorous coupled-wave analysis. Each nano-lens is designed to operate as a lens element that
focuses transmitted light. The results show the focal power increasing with the ring number and the enhancement of
achievable numerical aperture compared to that of conventional lenses.
Analytical modeling of plasmonic-waveguide-based devices for nanophotonic applications
Show abstract
The design and realization of chip-scale plasmonic devices have been considerably facilitated by computational
electromagnetic simulations and sophisticated nanofabrication techniques. For rapid device optimization, numerical
simulations should be supplemented by simple analytical expressions capable of providing a reasonable
estimate of the initial design parameters. In this paper, we develop an analytic approach and derive approximate
expressions for the transmittance of metal-dielectric-metal (MDM) waveguides coupled to single, double, and
periodic stub structures. Our method relies on the well-known analogy between MDM waveguides and microwave
transmission lines, and enables us to use standard analytical tools in transmission-line theory. The advantage of
our analytic approach over the previous studies is in accounting for the plasmon damping due to Ohmic losses
and reflection-induced phase shift at the stub end. We found that the analyzed waveguide configurations can
exhibit the characteristics of nanoscale filters and reflectors. We validate our analytical model by comparing
its predictions with numerical simulations for several MDM waveguides with different stub configurations. The
proposed theoretical results are particularly useful to reduce lengthy simulation times and will prove valuable in
designing and optimizing MDM-waveguide-based photonic devices.
Effects of amplitude and timing jitter on the performance of photonic sigma-delta modulators
Yean Wee Tan,
Chang Ho Nam,
Phillip E. Pace
Show abstract
Photonic sigma-delta modulators can directly digitize wideband signals with high resolution directly atthe antenna.
In our first-order, single-bit architecture, the antenna signal is applied to a pair of Mach-Zehnder interferometers and
oversampled using a CALMAR 10 GS/s mode-locked laser (MLL) with a pulse width of 10 ps. The measurements
of the MLL pulse-to-pulse sample time uncertainty (time jitter) and the laser pulse amplitude uncertainty (amplitude
jitter) are described. Considering the jitter to be the result of non-uniform random sampling we show that a normal
distribution is a good noise model for both jitter mechanisms. The sigma-delta modulator and the decimation
filtering process are described. Using asynchronous spectral averaging of the reconstructed signal's magnitude
spectrum, an expression for the noise floor without jitter is developed and compared to simulation results as a
function of the oversampling ratio (OSR) and record length using a 100 MHz signal bandwidth. The noise floor is
then evaluated as a function of the time jitter power and amplitude jitter power for several OSRs.