Optimax (United States)

To unlock the potential of space, there is a push for better optical imaging, including for larger parabolic on and off-axis mirrors. Costs and lead times have prohibited many programs from scaling. To answer this call, Optimax is developing manufacturing capabilities using a Lean Cell approach, where generation, polishing, smoothing, final figuring, and core metrology are centrally located and tightly controlled. This approach, and its adaptability, will allow lead time reduction from 60+ weeks to eight weeks for 0.5 m optics. Because all components are contained in one cell, ownership of results is carefully monitored by engineers and technicians from start to finish, increasing the quality and decreasing the decision-making time between steps. Finally, advances in the coating capabilities allow for a variety of customized, 0.5 m optic size coating formulations to finish the process. Data from recent projects will be shared to highlight the process and capabilities.

High-quality aspherical and freeform surfaces are in high demand, and the high-accuracy form measurement of such surfaces is a challenging task. To explore the current status of form measurement systems for complex surfaces such as aspheres and freeforms, interlaboratory comparison measurements are performed. This study presents the pseudonymized results obtained using three different surfaces (metal asphere, glass asphere, toroidal surface) in a total of six different round robins. These results were taken from a total of 13 different measurement instruments based on 9 different measurement principles and operated at 12 different laboratories. They were analyzed using a sophisticated procedure that was first developed in 2018 and then refined and tested on simulated data in 2022 to address the challenges of such a comparison at this level of accuracy. In the current study, we applied these refined methods to data acquired from tactile and optical point measurements as well as from optical areal measurements. As there are no absolutely measured and very well characterized reference standard aspherical and freeform surfaces available at the accuracy level of a few tens of nanometers root-mean-square, the approximated true forms of the surfaces were derived from the measurements and indicate the manufacturing accuracy of the surface forms. Then, the measurement’s differences to the approximated true forms were analyzed, which directly indicate the systematic measurement errors of the instruments. By also comparing the approximated true forms from the two different round robins for each surface, additional insights into the reliability and stability of these so-called virtual reference topographies were gained.

BackgroundPopulation size and structure have a huge impact on health indicators. In countries with a high proportion of expatriates, there are some limitations in estimating, aggregating and reporting of the health indicators, and corrections may be required in the established estimation methodologies. We review the case of Qatar to see how its specific population characteristics affect its health indicators.MethodsWe used routinely collected data and reviewed and calculated a selected list of health indicators for Qatari and non-Qatari populations residing in Qatar. Mortality and cancer incidence rates, stratified by nationality, were used for this purpose. Also, a direct method was used to estimate completeness of the death registry, compared to the mortuary data.ResultsAge and sex distribution of Qatari and non-Qatari populations are completely different. Compared to the mortuary data, completeness of death registration for the total population was estimated at 98.9 and 94.3%, with and without considering overseas deaths, respectively. Both estimates were considerably higher than estimates from the indirect methods. Mortality patterns were different even after standardization of age and stratification of sex groups; male age-standardized mortality rates were 502.7 and 242.3 per 100,000 individuals, respectively for Qataris and non-Qataris. The rates were closer in female populations (315.6 and 291.5, respectively). The leading types of cancer incidents were different in Qataris and non-Qataris.ConclusionsExpatriates are a dynamic population with high-turnover, different from Qatari population in their age-sex structure and health status. They are more likely to be young or middle-aged and are less affected by age related diseases and cancers. Also, they might be at higher risks for specific diseases or injuries. Aggregating indicators of Qatari and non-Qatari populations might be mis-leading for policy making purposes, and common estimation correction approaches cannot alleviate the limitations. High-proportion of expatriate population also imposes significant errors to some of the key demographic estimates (such as completeness of death registry). We recommend a standardized approach to consider nationality in addition to age and sex distributions for analysis of health data in countries with a high proportion of expatriates.

One third of the exchanged final turning mirrors on the National Ignition Facility have been laser damaged by 3ω (351nm) target backscattered light. The mirrors are spectrally complex hafnia and silica multilayer dichroic coatings with high 1ω reflection for the forward propagating beam and low 3ω reflection to suppress propagation of target backscatter. Alumina, a wider bandgap high index material than hafnia, was selected to improve the 3ω laser damage resistance despite a lower refractive index. A 2-4x improvement in 3ω LIDT was demonstrated with adequate 1ω laser damage resistance. Nodule ejection was the dominate laser damage morphology. An 18% decrease in the refractive index between alumina and hafnia results in coating designs that are 3x thicker. Similarly, a decrease in refractive index also decreases the angular bandwidth resulting in increasing the number of mirror types from two to six over an angular range of 16 degrees. The significant improvement in 3ω LIDT has justified beginning a scale up demonstration to full aperture (0.3m²).

As U.S. manufacturing works to overcome a technical skills gap, apprenticeship is gaining favor as a post-secondary educational path. Registered apprenticeship is a structured program that requires on the job training of an employee, accompanied by related instruction, and a progressive wage scale as the apprentice progresses through the program. This presentation describes how the Occupation Title for a Precision Optics Manufacturing Technician was defined for the industry, and approved by the US Department of Labor (USDOL). The occupation was later deemed apprenticeable by the DOL, and the apprenticeship was designed and registered with NY State. The program entails a three year (6,000 hour) rotation through every department of an optics manufacturing firm, with defined outcomes regarding hours of experience and competencies gained. In this program, structured, hands on technical training is combined with theoretical class room learning to develop highly skilled manufacturing technicians. This presentation will explain many of the details surrounding registered apprenticeship, including adjustments and results encountered during the first three years of the Optimax program.

Freeform optical systems are becoming increasingly common due to new design and manufacturing methods. We present an example compact freeform optical system and describe considerations for transfer of the prescription of freeform surfaces for fabrication.

Optimax uses a variety of different 3D printers in our manufacturing process that streamline many aspects of the process. Measurement fixtures, machine repair and slurry containment are areas where 3D printing helps streamline manufacturing.

Photo-alignment technology is important for liquid crystal (LC) device applications where both high resistance to incident optical energy and spatially distributed alignment states over the device clear aperture are required. Coumarin-based photo-alignment materials developed at the Laboratory for Laser Energetics (LLE) possess near-IR laser damage resistance approaching that of fused silica and have been employed in the development and fabrication of a wide variety of LC high-peak-power laser optics. One example is a photo-patterned LC beam shaper, developed for use in LLE’s four-beam, petawatt-peak-power OMEGA EP laser, that has demonstrated 1054-nm, 1 ns laser-damage thresholds approaching those of dielectric thin-film Brewster’s angle polarizers (30 to 40 J/cm2). Achieving similar performance levels in LC devices for near-UV applications is challenging due to a scarcity of both UV-transparent LC materials and polymer alignment layers that can withstand repeated exposure to intense pulsed- or CW UV irradiation without degradation. Previously-employed alignment materials for UV-LC devices such as buffed polyvinyl alcohol (PVA) or Nylon 6/6 have limited usefulness; buffing embeds particulates and scratches into the alignment layer that reduce its UV damage thresholds to only a few J/cm2 and is incapable of producing highly resolved and spatially-distributed LC alignment states. In recent experiments, we have found that coumarin photoalignment materials are remarkably more resistant to damage from both incident 351 nm, 1 ns high-energy laser pulses [~11.42 J/cm2 (1-on-1) and ~15.70 J/cm2.(N-on-1)] and broad-band, continuous wave (CW) UV-visible light than would be expected due to their highly conjugated aromatic electronic structures. This finding opens a new chapter in the development of LC devices for UV applications in high-peak-power lasers (e.g. wave plates, polarization rotators, radial polarization converters, photo-patterned beam shapers) and other areas of optics and photonics where UV stability is important (e.g., space-based applications).

This work briefly discusses the need for engineered and targeted optical cleaning processes to meet the specific demands of an application and how Optimax has addressed these concerns.

Freeform optical shapes or optical surfaces that are designed with non-symmetric features are gaining popularity with lens designers and optical system integrators. Tolerances on a freeform optical design influence the optical fabrication process. Case studies and soft tolerance limits for easier fabrication will be discussed. This paper will also give a high level overview of a freeform optical fabrication process that includes generation, high speed VIBE polishing, sub-aperture figure correction and testing of freeform surfaces.