Discuss Performance of Corner-Cube Prism for Modulating Retro-Reflector Terminal in Free-Space Laser Communication
Modulating Retro-reflector terminal does not need capture, tracking, targeting(ATP) sub-system .The key unit of this type structure is corner- cube prism,its performance will cause the light beam intensity distribution and light beam divergence angle .There are several factors ,such as effective area , right-angle accuracy, surface-type errors .Those errors caused loss of light power result in communication fail,so in this paper we made a precise analysis as a supplement.
Optical communications development for spacecraft applications
Free-space optical communications systems for deep space and near-terrestrial space environments are now poised for deployment aboard spacecraft. Although many fundamental technical problems have been solved, detailed engineering development is still needed to make space-worthy optical communications terminals. Very high bandwidths (10 Gbps or higher) and fine (1-to 10-μrad accuracy) pointing systems are needed for near-terrestrlal space. For deep space applications, optical links at competitive bandwidths relative to RF systems (e.g., 30 Mbps) with very fine pointing accuracies (<1 μrad) are planned. Deep space applications also require very sensitive receivers and large ground receiving apertures, while minimizing mass and prime power penalties for the added capability, especially for smaller spacecraft. Recent efforts at APL focusing on these issues are summarized in this article.
High-Performance Chirped Electrode Design for Cat's Eye Retro-Reflector Modulators
Modulating retro-reflector (MRR) systems typically use large area surface-normal modulators with large lateral current flow. Frequency response is limited by the resistance capacitance time constant. In cat's eye MRRs, only a small percentage of the modulator area is illuminated at a time. Uniform resistance to each part of the modulator is desired to decrease location dependence of frequency response. A novel "chirped" grid electrode was designed to balance semiconductor sheet resistance and metal line resistance components of the series resistance. Measured rise/fall times across the device showed good uniformity