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Conference 13134
Optical Manufacturing and Testing 2024
20 - 22 August 2024 | Conv. Ctr. Room 16A (Tue-Wed); Room 11A (Thu)
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Poster Session
19 August 2024 • 5:30 PM - 7:00 PM PDT | Conv. Ctr. Exhibit Hall A
Conference attendees are invited to attend the poster session on Monday evening. Come view the posters, enjoy light refreshments, ask questions, and network with colleagues in your field. Authors of poster papers will be present to answer questions concerning their papers. Attendees are required to wear their conference registration badges to the poster sessions.
Poster Setup: Monday 10:00 AM - 4:30 PM
Poster authors, view poster presentation guidelines and set-up instructions at https://spie.org/OP/poster-presentation-guidelines
Poster Setup: Monday 10:00 AM - 4:30 PM
Poster authors, view poster presentation guidelines and set-up instructions at https://spie.org/OP/poster-presentation-guidelines
13134-36
19 August 2024 • 5:30 PM - 7:00 PM PDT | Conv. Ctr. Exhibit Hall A
Show Abstract +
The precision fabrication of x-ray mirror substrates is crucial to achieving a lightweight, high resolution and large effective area x-ray telescope mirror system for observational astronomy. Ultrafast Laser Stress Figuring (ULSF) is a promising figuring technique, useful even after assembly and coating, but requires a smooth substrate whose figure is accurate to within tens of microns. Moldless slumping is a potential technique to provide these substrates, by avoiding contact with a mold that introduces mid-spatial frequency error. This study investigated the mid- and low-spatial frequency errors introduced by moldless slumping of Corning Eagle XG glass into cylindrical shapes. We varied the temperature and time of slumping on a predesigned frame, afterwards mapping the curved substrate surface using interferometry to assess these spatial frequencies of the surface through Zernike terms, enabling the repeatability from substrate to substrate, and for spatial frequency error correction through ULSF. In this case, we concluded that the curved substrate surfaces are smooth and that the RMS height error over 50 mm aperture is 2.03 microns with a mid-spatial RMS of 0.0075 microns.
13134-37
19 August 2024 • 5:30 PM - 7:00 PM PDT | Conv. Ctr. Exhibit Hall A
Show Abstract +
We conducted a mechanical processing experiment on a grid pattern to use Si material, which has low mechanical processing properties, as a grating spectroscopic device. Cutting was performed using ultra-precision grooving equipment with the shape of the tool, feed speed, and depth of cut as variables. The quantitative indicator is the surface roughness of the pattern surface, and each measurement area was measured repeatedly using a white light interferometer. As a result of these results, we analyzed the tendency of surface roughness according to processing conditions.
13134-38
19 August 2024 • 5:30 PM - 7:00 PM PDT | Conv. Ctr. Exhibit Hall A
Show Abstract +
This study shows a novel approach for the optical finishing method using a gas cluster ion beam (GCIB).
13134-39
19 August 2024 • 5:30 PM - 7:00 PM PDT | Conv. Ctr. Exhibit Hall A
Show Abstract +
This paper describes a process for measuring a thin film of MgF2 using an LCD to compensate for experimental interferograms in a Twyman-Green arrangement. The process involves generating different gray levels to display a controlled distribution on an LCD pixel by pixel. Each gray level has been calibrated and associated with a phase value. The objective is to obtain contiguous bands in all interferograms, which can be achieved by sectioning the screen into several gray levels. The proposal can also be used to compensate for the profile of an arbitrary surface with manufacturing errors.
13134-40
19 August 2024 • 5:30 PM - 7:00 PM PDT | Conv. Ctr. Exhibit Hall A
Show Abstract +
As wavefront quality demands tighten on space systems for applications such as astronomy and laser communication, mounting small optics such that the wavefront is undisturbed, positioning is adjustable and the design is producible, while surviving harsh space environments, is a continuing challenge. We designed multiple candidate flexure mounts to support small optics (up to 50 mm diameter, and over 100 grams) to survive the qualification and acceptance tests of small spacecraft and units as defined in ISO 19683 and a mounting structure which is adjustable in decenter [+/-0.5mm], tip/tilt +/-0.5deg, and piston [+/-0.25mm]. . We will present design details along with measurements showing less than approximately lambda/10 wavefront contribution from the optic bonding process, along with thermal and multi-axis vibration test data showing the mounted optics survived the acceptance testing loads and are suitable for operation in a wide range of harsh environments.
Session 1:
Optical Testing I
20 August 2024 • 8:40 AM - 10:10 AM PDT | Conv. Ctr. Room 16A
Session Chair:
Heejoo Choi, Wyant College of Optical Sciences (United States)
13134-1
20 August 2024 • 8:40 AM - 9:10 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Confocal probes, which consists of a point light source and a point detector, have been widely used in the manufacturing industry for a surface profile measurement of a measurement target object. In recent years, a mode-locked laser, which has advantages; high-stable optical frequency and wide-range optical frequency, and high-stable intensity, has been employed as a light source of the confocal probes, enabling to non-scanning and precise height measurement. However, a non-smoothness of the optical spectrum of the mode-locked laser affects a confocal response curve, which is utilized for the target position measurement, and leads to loss of the measurement accuracy. Therefore, a dual-detection chromatic confocal probe has been proposed and researched to reduce the effects of the non-smoothness optical spectra. In this paper, a review about the dual-detection chromatic confocal probe is summarized.
13134-2
20 August 2024 • 9:10 AM - 9:30 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Optical aspherical surfaces have become more widely used as they offer advantages such as improved image quality, compact design, increased light gathering, and reduced distortion. However, measuring aspherical surfaces presents challenges due to their non-spherical shapes. The primary difficulties include the complexity of surface geometries and the need for specialized metrology equipment. These challenges require advanced measurement techniques to ensure accurate characterization and quality control of aspherical surfaces in various applications. This paper introduces an innovative, AI-driven solution for the measurement of aspherical surfaces within the image space, offering a flexible optical metrology tool for measuring aspherical surfaces. This approach is characterized by its ability to deliver rapid and cost-effective integration without the need for custom, complex optics.
13134-3
20 August 2024 • 9:30 AM - 9:50 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Surface roughness measurement is essential for ensuring optical components, semiconductor substrates, and similar surfaces meet quality and performance standards. Precise characterization and control of surface irregularities enhance overall efficiency and performance. This paper introduces an AI-driven solution for surface roughness measurement in the image space, offering a versatile optical metrology tool. It offers a rapid, cost-effective integration, eliminating the need for scanning in most applications. AI algorithms initially determine the fundamental surface figure. They then extract higher spatial frequencies related to surface roughness using AI-driven phase retrieval techniques. This approach enables comprehensive surface roughness profiling and estimation of statistical parameters like Ra and Rq, crucial for quality control. The solution is ideal for high-throughput applications, ensuring precise surface quality assessment. In conclusion, this AI-driven solution revolutionizes surface roughness measurement, benefiting industries working with optical components, semiconductor. This paper introduces the method and results using a Point Source Microscope (PSM) from OPG.
13134-41
20 August 2024 • 9:50 AM - 10:10 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Spaced-based mirrors that operate in cryogenic temperatures have a decreased gravity sag value than their phase maps at 293k. To characterize how the gravity sags changes at cryogenic temperatures a 1.2m aluminum mirror made of 5083 had a horizontal rotation test done for N=3 rotations (0°, 120°, 240°) for multiple temperatures ranging from 293k to 35K.
Break
Coffee Break 10:10 AM - 10:40 AM
Session 2:
Optical Testing II
20 August 2024 • 10:40 AM - 12:10 PM PDT | Conv. Ctr. Room 16A
Session Chair:
Jonghan Jin, Korea Research Institute of Standards and Science (Korea, Republic of)
13134-4
20 August 2024 • 10:40 AM - 11:10 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
In optical metrology, the growing demand for high-quality digital twins of surface measurement technologies, driven by increased applications of three-dimensional microscopy and imaging, is met through the development of virtual instruments (VIs). A VI replicates an optical instrument, allowing for enhanced understanding, optimisation and uncertainty evaluation of measurements. Coherence scanning interferometry (CSI), a common technique for accurate surface topography measurement, can be modelled using both approximate and rigorous scattering models. While approximate models are computationally efficient, rigorous models based on Maxwell’s equations offer high-accuracy solutions for complex light-matter interactions. Our study employs virtual coherence scanning with both model types, comparing their results, and proposing a procedure for uncertainty evaluation.
13134-5
20 August 2024 • 11:10 AM - 11:30 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Multi-wavelength interferometer is one of the most widely used methods for measuring absolute distances with high precision, which typically uses more than three frequency-stabilized lasers to solve the phase ambiguity problem. However, despite its high measurement precision, it is practically not easy to install and maintain several frequency-stabilized lasers. In this work, we proposed and realized a multi-wavelength interferometer using an electro-optic comb with a wide frequency mode spacing, which is enough to consider each frequency mode as a single laser. Absolute distance was measured using the proposed method, and measurement uncertainty was estimated for performance evaluation.
13134-6
20 August 2024 • 11:30 AM - 11:50 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
In a multi-wavelength interferometer using an electro-optic comb with a wide frequency mode spacing, the phase of each frequency mode, or wavelength, can be determined through phase shifting with the reference mirror scanning at constant intervals. Since each frequency mode has a different wavelength, the phase change for the same controlled mirror displacement varies. Therefore, a model-based analysis of phase shifting data was employed for phase determination at each wavelength. In this study, we aim to estimate the phase determination uncertainty according to the number of phase shifts through numerical simulations in the model-based analysis approach.
13134-7
20 August 2024 • 11:50 AM - 12:10 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
Development of the dynamic null lens that generate wide range of aberration yields flexible and effective interferometric testing method. In this research, Offner null lens which employ two spherical plano-convex lenses have been used to create variable spherical aberration by changing lens position. Thanks to zoomable two spherical plano-convex lenses, it has been shown different aspheric surfaces can be tested with just one test equipment while keeping manufacturing, verification and alignment error at low level.
Break
Lunch/Exhibition Break 12:10 PM - 1:40 PM
Session 3:
Optical Testing III
20 August 2024 • 1:40 PM - 3:00 PM PDT | Conv. Ctr. Room 16A
Session Chair:
Heidi Ottevaere, Vrije Univ. Brussel (Belgium)
13134-8
20 August 2024 • 1:40 PM - 2:00 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
This on-axis deflectometry design utilizes a pattern on a liquid crystal display reflected by a parabolic mirror into a CMOS camera at the mirror's focal point. An initial image is taken in this null configuration and then a second image is taken when a test lens is placed between the mirror and camera. These differences in the two images are used to determine the lower order spatial frequency information about the test sample’s through wavefront error (WFE). The reconstructed WFE maps from the system measurements are compared to the reconstructed WFE maps of the same test sample using a Zygo Verifire interferometer. The placement of the camera at the focal length of the parabolic mirror creates collimated light conditions between the parabolic mirror and the monitor. This removes the local slope calculation dependency on the axial position of the monitor and reduces height-slope ambiguities found in traditional deflectometry systems.
13134-9
20 August 2024 • 2:00 PM - 2:20 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
Modulation transfer function (MTF) is a critical optical measurement that represents the image resolution available from a single lens or an optical system. Although a critical measurement, MTF measurements are in urgent need of improved standardization. To address this critical technical issue, the U.S. Army and Peak Nano Optics, LLC. have executed a Gauge R&R (repeatability and reproducibility) study between lens metrology equipment measuring a common group of lenses at different facilities. The Gauge R&R study was designed to sort out the variations in a measurement process attributable to the equipment operators, the measurement procedures, the metrology equipment, and variation in the samples being measured.
13134-10
20 August 2024 • 2:20 PM - 2:40 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
Traditional surface metrology mainly focuses on measuring distances between the sensor and the workpiece to gain insights into the geometric properties of the workpiece. Surface texture parameters however may not always offer a comprehensive understanding of a surface's functional aspects. For certain applications that require highly sensitive process monitoring, the distribution of the surface gradient can serve as a crucial measure.
The presented study aims to establish a direct correlation between the angular resolved scattering light distribution and the functional characteristics of surfaces. A direct measurement of the angular distribution does not exhibit the potential deviations that occur during the numerical derivation of measured topography data. While the sensor principle is commonly used for process monitoring, the relationship between the angular distribution and functional characteristics like wear, friction, and lubrication has not been widely described. We compare topography measurements and associated surface texture parameters with information derived from angular resolved scattering light measurements. Cylinder liner surfaces serve as a case study.
Break
Coffee Break 3:00 PM - 3:30 PM
Optical Engineering Plenary
20 August 2024 • 3:30 PM - 5:35 PM PDT | Conv. Ctr. Room 6A
Session Chairs: Alexander M. J. van Eijk, TNO Defence, Security and Safety (Netherlands) and Jeremy P. Bos, Michigan Technological Univ. (United States)
3:30 PM - 3:35 PM:
Welcome and Opening Remarks
3:30 PM - 3:35 PM:
Welcome and Opening Remarks
13138-501
Sense making from multi-source, electro-optical, remote sensing constellations
(Plenary Presentation)
20 August 2024 • 3:35 PM - 4:15 PM PDT | Conv. Ctr. Room 6A
Show Abstract +
With 140+ petabytes of historical data holdings, 3.8 million square kilometers of daily multi-spectral collection, integration of Synthetic Aperture Radar and newly launching assets every quarter, the opportunities to develop insight from sense making technologies at Maxar are ever growing. During this discussion, we will cover the challenges of collecting, organizing, and exploiting multi source electro-optical remote sensing systems at scale using modern machine learning architectures and techniques to derive actionable insights.
13131-501
Freeform optics: applications and challenges
(Plenary Presentation)
20 August 2024 • 4:15 PM - 4:55 PM PDT | Conv. Ctr. Room 6A
13145-501
The Roman Space Telescope Observatory build, test, and verification status
(Plenary Presentation)
20 August 2024 • 4:55 PM - 5:35 PM PDT | Conv. Ctr. Room 6A
Show Abstract +
The Nancy Grace Roman Space Telescope (“Roman”) was prioritized by the 2010 Decadal Survey in Astronomy & Astrophysics and is NASA’s next astrophysics flagship observatory. Launching no earlier than 2026, it will conduct several wide field and time domain surveys, as well as conduct an exoplanet census. Roman’s large field of view, agile survey capabilities, and excellent stability enable these objectives, yet present unique engineering and test challenges. Roman comprises a Spacecraft and the Integrated Payload Assembly (IPA), the latter of which includes the Optical Telescope Assembly (OTA), the primary science Wide Field Instrument, a technology demonstration Coronagraph Instrument, and the Instrument Carrier, which meters the OTA to each instrument. The Spacecraft supports the IPA and includes the Bus, Solar Array Sun Shield, Outer Barrel Assembly, and Deployable Aperture Cover. It provides all required power, attitude control, communications, data storage, and stable thermal control functions as well as shading and straylight protection across the entire field of regard. This paper presents the Observatory as it begins integration and test, as well as describes key test and verification activities.
Lens Design Technical Event
20 August 2024 • 8:00 PM - 10:00 PM PDT | Marriott Marquis, Catalina
View Full Details: spie.org/lens-design
Session Chair: Scott Lerner
"Let's Give 'Em Something to Talk About!"
Lens designers! Join us for our annual gathering to meet and discuss…lens design! This year's featured speakers will be Dave Aikens and Mary Turner.
Co-sponsored by: Photon Engineering
Light refreshments sponsored by: The Optical Solutions Group at Synopsys
Session 4:
Telescope System I
21 August 2024 • 9:00 AM - 10:00 AM PDT | Conv. Ctr. Room 16A
Session Chair:
Heejoo Choi, Wyant College of Optical Sciences (United States)
13134-12
21 August 2024 • 9:00 AM - 9:20 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Precise characterization of deformable mirrors (DMs) is crucial for optimizing wavefront sensing/control systems. This study employs a 4D PhaseCam 6000 interferometer to analyze the temporal behavior of a 97-actuator ALPAO DM under varying aberration levels. Measurements of RMS difference, peak-to-valley difference, and the first 37 Zernike polynomials change reveal a strong correlation between applied aberration and temporal variation. A trend of higher standard deviation is noticed in the applied aberration to the DM over time.
13134-13
21 August 2024 • 9:20 AM - 9:40 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Large Aperture Mirrors (LAMs) are critical components of space- and ground-based telescopes and surveillance systems. The need exists in assessing temporal multiple modality dynamics of various types of LAMs, including recently developed mirrors with membrane support structure and 3D printed mirrors. This presentation discusses practical results for Whole-Field Laser Doppler Vibrometer (WF-LDV) - a newly developed instrument capable of instantaneous characterization of LAM’s vibrational spectra. Contrary to typical single beam scanning LDV or laser-beam array matrix LDV, the whole-field LDV used in this study operates in global mirror illumination mode while pixilation of the data is performed at the receive. Given the capacity of the WF-LDV to capture and characterize structural vibration in real time with negligible latency, it is possible to adaptively excite and probe the LAM allowing rapid convergence on resonant modes combined with Dynamic Mode Decomposition of the dynamics of the mode evolution.
13134-14
21 August 2024 • 9:40 AM - 10:00 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Optics manufactured in a gravitational field are made with inherent internal stresses. When these optics are removed from the gravitational field (I.E., put into space) these stresses release. This is referred to as G-release. Theory offers methods of predicting the resulting 0-G shape of these optics. The intent of this paper is to compare results of real data measured on the same mirror from two separate methods; the ‘N-1 rotation test’ and the ‘face up/face down test’.
Break
Coffee Break 10:00 AM - 10:30 AM
Session 5:
Telescope System II
21 August 2024 • 10:30 AM - 12:00 PM PDT | Conv. Ctr. Room 16A
Session Chair:
James P. Hamilton, Photonic Cleaning Technologies (United States)
13134-15
21 August 2024 • 10:30 AM - 11:00 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Photonic lanterns are a powerful emerging technology with critical applications in wavefront sensing, ultra-resolution hyperspectral imaging, telecommunications, adaptive optics for deep turbulence, LIDAR, directed energy, and astronomical investigations of extrasolar planets. A photonic lantern is a monolithic optical fiber device consisting of a smooth, continuous 3-D waveguide transition that implements spatial transformations. The lantern effectively decomposes the input light into eigenmodes of the lantern, with each mode corresponding to an output SMF. Thus, we can measure the distribution of intensities among the output single-mode beams to reconstruct the incoming optical field. Our group has pushed lanterns to high coupling efficiencies, with demonstrated broadband (400-700nm) transmission >91%, with efficiency rising to >97% for wavelengths approaching 1000nm and beyond. A rapidly expanding application of photonic lanterns is in the area of wavefront sensing. We will present our recent developments for Photonic Lantern WaveFront Sensors (PLWFS), with particular emphasis on their potential applications for optical system metrology and aberration control.
13134-16
21 August 2024 • 11:00 AM - 11:20 AM PDT | Conv. Ctr. Room 16A
Show Abstract +
Continuous wavefront sensing benefits space observatories in on-orbit optical performance maintenance. Phase retrieval is an attractive technique to collect phase of a wavefront without additional metrology systems nor complicated calibration. In this study, we tested the performance of the phase retrieval algorithm on broadband under various cases. We investigated the effect of bandwidth and signal-to-noise ratio to the accuracy of the algorithm. We also investigated the effect of the amount of defocus in dynamic range and the accuracy. Finally, we simulated the continuous wavefront sensing and correction with a range of statistically generated representative telescope disturbance time series to test for edge cases. data that is generated based on the operation circumstances.
13134-18
21 August 2024 • 11:40 AM - 12:00 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
We are developing a Hybrid Wavefront Sensor (HyWFS) which combines the high dynamic range of a Shack-Hartmann wavefront sensor and the high sensitivity of an unmodulated pyramid wavefront sensor. In our prototype light is focused on a crossed roof prism and subsequently passed through a lenslet array creating four arrays of focal points corresponding to each of the four pupils. This allows us to simultaneously perform both Shack-Hartmann and pyramid wavefront sensing analyses on aberrated wavefronts. This hybrid method would allow continuous wavefront corrections using a deformable mirror during turbulent events that would saturate an unmodulated pyramid wavefront sensor functioning alone. Experimental results confirm the HyWFS has high sensitivity to weak aberrations while maintaining robustness against stronger aberrations due to the amalgamation of wavefront sensing techniques.
Break
Lunch/Exhibition Break 12:00 PM - 1:30 PM
Session 6:
Telescope System III
21 August 2024 • 1:30 PM - 3:00 PM PDT | Conv. Ctr. Room 16A
Session Chair:
Jessica DeGroote Nelson, Edmund Optics Inc. (United States)
13134-19
Integration and testing of off-axis freeform three-mirror system K-DRIFT Generation 1
(Invited Paper)
21 August 2024 • 1:30 PM - 2:00 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
We are under testing the KASI Deep Rolling Imaging Fast Telescope Generation 1 (K-DRIFT G1) using an interferometer and flat mirror at 633 nm. The telescope is a confocal off-axis freeform three-mirror system designed for the detection of extremely low surface brightness structures in the sky. The optical specifications of the K-DRIFT G1 are as follows: the entrance pupil diameter is 300 mm, the focal ratio is 3.5, and the field of view is 4.43° × 4.43°. During the integration stage, we used a coordinate measuring machine to measure the positions of the mirrors, flexures, and bezels within a tolerance range. Following the system integration, we are currently measuring wavefront errors at several edge fields using an interferometer at 633 nm. In this paper, we briefly present the current status of the K-DRIFT G1 and the future plans for the project.
13134-20
21 August 2024 • 2:00 PM - 2:20 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
In 2017, the European Southern Observatory (ESO) awarded a contract for the Polishing, integration and final figuring of the Segment Assemblies of the primary mirror (M1) for the Extremely Large Telescope (ELT) to Safran Reosc. Since then, the design and commissioning of a production unit dedicated to ELT M1 has been accomplished and the plant has been producing many mirrors since spring 2022. We will introduce the smart factory, its processes and their automation that enabled reaching the current throughput of one mirror per day. We will then present the status of the project, some lessons learned and highlight the successes that have been achieved so far.
13134-21
21 August 2024 • 2:20 PM - 2:40 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
UVO to Far-IR (UVO-FIR) mirror technology development project is a multiyear effort initiated in Fiscal Year 2022 to mature the Technology Readiness Level of critical technologies required to enable ultra-stable telescope of the Habitable Worlds Observatory (HWO) mission. This paper will summarize 2023/24 accomplishments.
13134-22
21 August 2024 • 2:40 PM - 3:00 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
When a telescope doesn’t reach a reasonable point spread function on the detector or detectable wavefront quality after initial assembly, a coarse phase alignment on-sky is crucial. Before utilizing a closed loop adaptive optics system, the observatory needs a strategy to actively align the telescope to align the telescope sufficiently for fine wavefront sensing (WFS). This paper presents a method of early-stage alignment using stochastic parallel-gradient-descent (SPGD) which performs random perturbations to the TMA telescope optics. The SPGD algorithm will drive the telescope until the wavefront error is below the acceptable range of the fine AO system to hand the telescope over. The focused spot size over the field is adopted as a feed parameter to SPGD algorithm and wavefront peak-to-valley error values are monitored to directly compare our mechanical capabilities to our alignment goal of diffraction limited imaging and fine wavefront sensing.
Break
Coffee Break 3:00 PM - 3:30 PM
Session 7:
Telescope System IV
21 August 2024 • 3:30 PM - 4:40 PM PDT | Conv. Ctr. Room 16A
Session Chair:
Heidi Ottevaere, Vrije Univ. Brussel (Belgium)
13134-23
21 August 2024 • 3:30 PM - 4:00 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
Optical alignment of the Coronagraph Instrument (CGI) was completed in time to begin its full-functional and environmental testing in late 2023 and its integration into the Roman Space Telescope (RST) in summer 2024. The optics of the CGI relay the optical pupil of the RST five times so that science operations, such as coronagraphy and wavefront control, can be conducted in the different internal pupil and image planes. Within the pupil relays, the CGI has multiple active optical assemblies, including a fast-steering mirror, a focus-control mirror, two deformable mirrors, and six precision alignment mechanisms that articulate different masks and apertures into the beam.
This paper details the many alignment steps required to successfully achieve the performance criteria of the CGI.
13134-24
21 August 2024 • 4:00 PM - 4:20 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
As part of the Decadal recommended Great Observatories Maturation Process (GOMaP) NASA has setup Working Groups and Sub-Working Groups to assess technology gaps and define technology development roadmaps for the potential Habitable Worlds Observatory. The Telescope Mirror Assembly and Structure Technology Sub-Working Group is analyzing technology to enable a large (6-m class) telescope with dynamic and thermal ultra-stable wavefront. The sub-group’s charter includes everything from material properties to sub-systems. Mirror assembly (primary and secondary) includes: material properties, substrate geometry, mounting and mechanisms, thermal sense and control, backplane structure, and secondary mirror support structure. Paper will review first year progress including technology gap assessment and draft TRL-5 technology roadmaps.
13134-25
21 August 2024 • 4:20 PM - 4:40 PM PDT | Conv. Ctr. Room 16A
Show Abstract +
The success of the James Webb Space Telescope (JWST) ignited the scientific
community to research a new era of telescope development. Furthermore, it is reasonable to
assume that there will be more missions of a similar nature and purpose in the future. From now
until the time the JWST is retired from service, updates in telescope, mounting, deployment, and
even launch technology capabilities will be realized. This thesis outlines the opto-mechanical
packaging of an Off-Axis -Three Mirror Anastigmat (OA-TMA). This optical system is designed
to have an entrance pupil diameter of 150 mm, a focal length of 407.185 mm, and a 2.10
x2.050
Field of View (FOV). The operational imaging waveband for this system is in the mid-wave
infrared band. The selected camera for this system is the Teledyne Neutrino QX1
. Because the
optical system is obscuration free, it results in a different packaging solution for space operation
than that of the JWST. The primary requirement of this system is to fold into a smaller volume
than its deployment configuration. The novel packaging method in this study resulted in a 66.7%
reduction of volume.
Featured Nobel Plenary
21 August 2024 • 5:00 PM - 5:45 PM PDT | Conv. Ctr. Room 6A
Session Chair: Jennifer Barton, The Univ. of Arizona (United States)
5:00 PM - 5:05 PM:
Welcome and Opening Remarks
5:00 PM - 5:05 PM:
Welcome and Opening Remarks
13115-501
The route to attosecond pulses
(Plenary Presentation)
21 August 2024 • 5:05 PM - 5:45 PM PDT | Conv. Ctr. Room 6A
Show Abstract +
When an intense laser interacts with a gas of atoms, high-order harmonics are generated. In the time domain, this radiation forms a train of extremely short light pulses, of the order of 100 attoseconds. Attosecond pulses allow the study of the dynamics of electrons in atoms and molecules, using pump-probe techniques. This presentation will highlight some of the key steps of the field of attosecond science.
Session 8:
Optical Manufacturing I
22 August 2024 • 9:00 AM - 10:20 AM PDT | Conv. Ctr. Room 11A
Session Chair:
Ray Williamson, Ray Williamson Consulting (United States)
13134-27
22 August 2024 • 9:00 AM - 9:20 AM PDT | Conv. Ctr. Room 11A
Show Abstract +
Fused silica is used in manufacturing optical components due to its excellent optical properties in the UV regions and low thermal expansion coefficient. A precision grinding machine with a finishing cup grinding wheel is used to grind spherical fused silica elements with a simultaneous three-axis controlled parallel grinding strategy. The study has two objectives: to identify the effects of feed speed and rotational speed ratio on the profile and waviness errors and to develop a machine learning framework to improve the prediction of profile errors. The experiment found that reducing the feed speed resulted in minimum waviness and profile errors at an RSR of 50.25. An ensemble learning regression framework was developed and demonstrated considerable predictive efficacy for the six unseen profile errors, with R-squared values from 0.74 to 0.98.
13134-28
22 August 2024 • 9:20 AM - 9:40 AM PDT | Conv. Ctr. Room 11A
Show Abstract +
Precision glass molding of optical lenses is similar to plastic injection molding, although a few fundamental differences exist between the two. One of the major disadvantages of the glass molding process over injection molding is the cycle time. The cycle time required for an injection-molded plastic lens can be less than 30 seconds, whereas an equivalent glass-molded lens may take anywhere from 15 to 30 minutes. Apart from the longer process times, the higher temperatures required by the glass molding process reduce the tool's lifetime thereby increasing the production costs. This paper presents a new glass press mold tooling that utilizes a multi-cavity approach with interchangeable mold pairs, enabling the production of multiple lenses in a single molding cycle. Further, the molding process as well as the tooling are optimized to achieve uniform accuracy and optical quality of the glass lenses across the mold plate.
13134-29
22 August 2024 • 9:40 AM - 10:00 AM PDT | Conv. Ctr. Room 11A
Show Abstract +
The measurement of mid-spatial frequency (MSF) in ultra-precision machining is crucial for assessing the quality and performance of machined surfaces. The sources which contribute to MSF errors during diamond turning are vibrations and dynamic instabilities, tool wear and deflection during cutting, inconsistent feed rates, variation in material properties, incorrect machine settings/process parameters, material removal mechanism employed. Controlling & measuring of mid-spatial frequencies in the diamond turning process is essential for meeting stringent optical specifications in various applications, such as lens manufacturing for imaging systems, telescopes, or laser systems etc. The inspection of MSF errors offline, or after the manufacturing process, is a common practice in quality control of optical surfaces. In this study, the influence of material properties and its impact on the mid-spatial frequencies during diamond turning is studied by using on-machine metrology (OMM).OMM provide real-time feedback which helps in adjusting machining parameters to correct deviations and maintain the desired mid-spatial frequencies.
13134-30
22 August 2024 • 10:00 AM - 10:20 AM PDT | Conv. Ctr. Room 11A
Show Abstract +
The OPTIMUS platform's laser-assisted technology has revolutionized ultra-precision diamond turning of tungsten carbide, employing a laser to enhance the diamond cutting tool's photon energy, thus minimizing mechanical energy dependence. This advancement builds on research into the tool rake angle's effect on cutting efficiency, exploring optimal rake angles combined with high laser power to maximize the Material Removal Rate (MRR). Preliminary findings indicate the ability to achieve a pre-polish ready optic with a 5 mm diameter aperture in just 20 minutes, significantly faster than the 2-3 hours required by traditional ultra-precision grinding, without compromising form irregularity and surface finish. Achieving an MRR nearly tenfold that of conventional methods, this technique represents a breakthrough for mass-producing tungsten carbide molds for glass optics. The study also provides a detailed comparison of the advantages and limitations of each technology, highlighting the potential of laser-assisted diamond turning in high-volume manufacturing settings.
Break
Coffee Break 10:20 AM - 10:50 AM
Session 9:
Optical Manufacturing II
22 August 2024 • 10:50 AM - 12:40 PM PDT | Conv. Ctr. Room 11A
Session Chair:
Daewook Kim, The Univ. of Arizona (United States)
13134-31
22 August 2024 • 10:50 AM - 11:20 AM PDT | Conv. Ctr. Room 11A
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This presentation delves into the key aspects of achieving sub-nanometer level deterministic ion beam figuring (IBF) of optical surfaces. Five aspects, including metrology, dwell time optimization, velocity scheduling, positioning, and final inspection, are discussed. Our solutions for the challenges in each aspect are highlighted.
13134-32
22 August 2024 • 11:20 AM - 11:40 AM PDT | Conv. Ctr. Room 11A
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This study explores a novel approach for optical system surface finish using Gas Cluster Ion Beam (GCIB).
13134-33
22 August 2024 • 11:40 AM - 12:00 PM PDT | Conv. Ctr. Room 11A
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We discuss optical elements based on the sulfur monochloride copolymers (DSG: disulfide glass, poly(S2-TIC-Cl2)) for IR imaging applications. DSG copolymers show high refractive index, excellent transparency, low birefringence, and low dispersion compared with conventional optical polymer materials. The excellent thermomechanical properties allow for both molding and diamond-turning fabrication. The diffraction angle of a molded optical diffraction grating agreed well with the design and a diamond-turned plano-convex lens shows a 1.8 times larger imaging area compared to a BK-7 lens of the same dimensions.
13134-34
22 August 2024 • 12:00 PM - 12:20 PM PDT | Conv. Ctr. Room 11A
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We present a high-performance, miniaturized endoscopic water-immersion objective compactly designed for nonlinear imaging. Traditionally, miniature microscopic objectives have been prototyped using diamond turning or molding techniques. Here, a hybrid manufacturing method employing 2.5D lithography technology has been developed to achieve high numerical apertures and large fields of view within compact dimensions, thereby enhancing their effectiveness in clinical settings.
13134-35
22 August 2024 • 12:20 PM - 12:40 PM PDT | Conv. Ctr. Room 11A
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Structural design of optical components launched into space requires fracture mechanics properties. To perform component design of a calcium fluoride (CaF2) prism, the fracture toughness and slow crack growth parameters were measured on the {100}, {110} and {111} low index planes. The fracture toughness is lowest on the {111} plane at 0.35 ± 0.01 MPam with a very flat cleavage surface exhibited during both fracture toughness and strength testing. Slow crack growth was significant on the {111} plane with a power law exponent of n = 30 ± 8. For engineering purposes, slow crack growth was insignificant on the {100} and {110} planes with n > 75. The facture surfaces have distinct patterns that are indicative of the cleavage plane. Biaxial testing with disks implies that design for general multiaxial states should be based on {111} strength and crack growth properties.
Conference Chair
Wyant College of Optical Sciences (United States), Large Binocular Telescope Observatory (United States)
Program Committee
Photonic Cleaning Technologies (United States), Univ. of Wisconsin-Platteville (United States)
Program Committee
Korea Research Institute of Standards and Science (Korea, Republic of), Korea National Univ. of Science and Technology (Korea, Republic of)
Additional Information
POST-DEADLINE ABSTRACTS ACCEPTED UNTIL 20 June
New submissions considered for poster session, or oral session if space becomes available
Contact author will be notified of acceptance by 8-July
View Submission Guidelines and Agreement
View the Call for Papers PDF
New submissions considered for poster session, or oral session if space becomes available
Contact author will be notified of acceptance by 8-July
View Submission Guidelines and Agreement
View the Call for Papers PDF
What you will need to submit
- Presentation title
- Author(s) information
- Speaker biography (1000-character max including spaces)
- Abstract for technical review (200-300 words; text only)
- Summary of abstract for display in the program (50-150 words; text only)
- Keywords used in search for your paper (optional)