Optical Characteristics of the Retroreflector in Space on the ADEOS Satellite in Orbit

Earth-to-satellite laser long-path absorption measurement of atmospheric trace gases

“…(1) The performance of the retroreflector having a curved mirror surface was demonstrated. The optical efficiency of RIS was evaluated by comparing the intensity of the reflected light at 532 nm with those of stars with known stellar magnitudes 9 . As the result, it was confirmed that the round-trip optical efficiency agreed well with the numerical simulation, and the efficiency at 10 µm was 10 -11 to 3×10 -9 depending on the location of RIS relative to the ground station when the transmitted beam divergence was 100 µrad and the diameter of receiver telescope was 1.5 m. (2) The active satellite tracking with an accuracy better than 30 µrad was achieved.…”

Switchable bifunctional metasurfaces: nearly perfect retroreflection and absorption at the terahertz regime

“…However, to the best of our knowledge, a single metasurface with dual functionalities of both perfect retroreflection and perfect absorber at the same operating frequency, has not reported yet. Retroreflection is a unique phenomenon that incident wave is reflected back by a surface or device to its source direction [20,21], which is strongly desired in laser tracking [22] or remote sensing [23]. In contrast with retroreflector used for signal detection, a perfect absorber can effectively eliminate the reflected signal, which could be used for anti-detection.…”