A document discusses an electro-optic sensor that consists of a collimator, attached to one segment, and a quad diode, attached to an adjacent segment. Relative segment-segment motion causes the beam from the collimator to move across the quad diode, thus generating a measureable electric signal. This sensor type, which is relatively inexpensive, can be configured as an edge sensor, or as a remote segment-segment motion sensor.
This work was done by Alex Abramovici of Caltech for NASA’s Jet Propulsion Laboratory. NPO-47528
This Brief includes a Technical Support Package (TSP).
Electro-Optic Segment-Segment Sensors for Radio and Optical Telescopes
(reference NPO-47528) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package from NASA, specifically focused on Electro-Optic Segment-Segment Sensors for radio and optical telescopes, referenced as NPO-47528 in NASA Tech Briefs. It aims to disseminate information about aerospace-related developments that have potential applications in various technological, scientific, or commercial fields.
Key highlights include the operational principles and variations of different sensor configurations, particularly emphasizing the use of photodiodes and quad diodes. The document discusses the sensitivity of these sensors to optical power variations and the methods employed to mitigate these effects. For instance, the split photodiode configuration is noted for its insensitivity to changes in optical power, achieved by using the ratio of difference and sum currents. This approach helps reduce measurement sensitivity to beam shape variations.
The document also introduces the Lateral Cell/Position Sensitive Detector (PSD) and quad diode configurations. The PSD is preferred for applications requiring small beam sizes and extended measurement ranges, while the quad diode configuration offers a balance between range and resolution, especially when dealing with Gaussian beams. The importance of protecting the beam against environmental factors, such as air flow and turbulence, is also highlighted, with suggestions for using protective measures like plastic tubes.
Additionally, the document provides contact information for further inquiries, directing readers to the Innovative Technology Assets Management at JPL for additional research and technology information. It emphasizes that the information is provided under the Commercial Technology Program and includes a disclaimer regarding liability and endorsement by the U.S. Government.
Overall, the document serves as a comprehensive resource for understanding the advancements in electro-optic sensor technology, their operational principles, and their applications in the field of astronomy and beyond. It reflects NASA's commitment to sharing knowledge and fostering innovation in aerospace technology.
