Electro-Optical Systems
I led the manufacturing integration, test infrastructure, and validation of a wedge-based optical sensing system designed to measure angular motion at micro- to nano-radian scales in space environments. The work focused on ensuring that passive optical components, sensors, and electronics could be assembled, aligned, and qualified to meet stringent performance and reliability requirements while minimizing mechanical complexity.
The system uses stacked optical wedges and position-sensitive detectors to convert extremely small angular changes into measurable lateral laser beam shifts, enabling stable and repeatable orientation sensing without moving parts. One application supports spacecraft attitude determination, including sun and star tracking, where controlled refraction maps incoming light onto sensors with high angular fidelity.
A second application uses internally referenced laser paths and wedge optics to measure relative angular motion within the spacecraft, detecting subtle structural or thermal distortions that impact optical alignment and pointing stability. Across both use cases, this approach provides high sensitivity, thermal stability, and long-duration mission reliability through mechanically simple, passive optics.
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High angular sensitivity and repeatability
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Strong thermal and environmental stability
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Compatibility with space qualification and long-duration missions
Electrochromic Smart Film as a Steady-State Optical Shutter
To protect the internal metrology optics and sensor electronics during non-measurement states, an electrochromic (EC) smart film was integrated into the optical path as a steady-state optical shutter. The EC film provides electrically controlled modulation of optical transmission, allowing the system to transition between a transparent measurement state and an attenuated or opaque protective state without introducing moving mechanical components. In its opaque state, the film shields the wedge prism and position-sensitive detector from prolonged laser exposure, stray light, and contamination during idle, launch, or non-operational phases. Once the system reaches thermal and mechanical steady state, the EC film is driven to a transparent state, enabling high-precision laser deflection measurements without disturbing optical alignment or introducing dynamic jitter.
This framing clearly communicates:
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Why it exists? Protection + system health
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What role does it plays? Acts as an optical shutter
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Why was EC chosen? No moving parts, stable, controllable and low power requirements.
Gravity Release Modeling and Validation for Large-Aperture Optics
Large-aperture optical systems are manufactured and tested under Earth’s 1g environment, but operate in microgravity once deployed in space. For optics ranging from roughly 2 to 6 meters in diameter, gravity-induced sag during manufacturing and test can introduce deformations that relax or redistribute under 0g conditions, altering the on-orbit optical figure and alignment. To account for this gravity release effect, structural and optical finite element models are used to predict deformation between 1g and 0g states. These models are validated during ground testing using flip or rotation methods, where the optic is measured in multiple orientations to isolate gravity-dependent deformation. Correlating measured deflections with FEA predictions ensures that the optical system will achieve the required figure and alignment once gravity loads are removed on orbit.
Thermally Actuated Optical Alignment Structure
This project focused on the testing and validation of a novel optical alignment architecture for large-aperture space telescopes, conceptually similar to segmented or strut-supported systems such as the James Webb Space Telescope. In this configuration, a large primary optical element is supported by three structural struts connecting the mirror assembly to downstream sensors and instruments.
Traditional alignment systems for these architectures rely on mechanical actuators, cables, gears, or pulley-driven mechanisms to achieve translational and rotational adjustment. In contrast, the system under evaluation used controlled thermal deformation to produce fine positional motion. Heating and cooling elements were embedded along each of the three support arms, allowing intentional thermal gradients to be introduced. These gradients produced small, predictable changes in strut length, enabling precise rotational and translational adjustment of the optical assembly without moving mechanical joints.
Validation testing was conducted on a full-scale structural assembly within a thermal-vacuum chamber to replicate the space environment. Testing characterized the total achievable rotational and translational motion, positioning accuracy, repeatability, and long-term stability. Life-cycle testing was also performed to ensure that repeated thermal actuation produced elastic, reversible deformation and did not introduce structural fatigue or performance degradation over the expected mission lifetime.
