High-speed free-space traveling-wave photodetector

Summary form only given. Because of the large quantum efficiency and sensitivity of photodiodes, this increase in the dynamic range could only result from an improved saturation intensity of the photodetector. Several methods have been proposed to increase this intensity that are mostly related to traveling-wave structures. To benefit from a large detection volume, with independently optimized dimensions, we propose a new concept in which the synchronous propagation of the detected modulated light and of the photogenerated microwave signal is obtained through the use of a diffraction grating, providing time delays on the free-space propagating laser beam.