High-speed 1.3 μm GaAs internal photoemission resonant cavity enhanced photodetector

Resonant cavity enhanced (RCE) photodetectors offer the possibility of overcoming the low quantum efficiency limitation of conventional photodetectors. The RCE detectors are based on the enhancement of the optical field within a Fabry-Perot resonator. The increased field allows the use of a thin absorbing layer, which minimizes the transit time of the photogenerated carriers without hampering the quantum efficiency. Recently, we fabricated high-speed RCE p-i-n and Schottky photodetectors, where a 90% quantum efficiency along with a 3-dB bandwidth of 50 GHz has been reported. We used the transfer matrix method to design the epilayer structure and to simulate the optical properties of the photodiode. The samples were fabricated by a microwave-compatible process and high-speed measurements were made with an optical parametric oscillator.