Resonant-cavity-enhanced p-i-n photodiode with a broad quantum-efficiency spectrum by use of an anomalous-dispersion mirror

A resonant-cavity-enhanced photodiode with broad filter transmittance and high quantum efficiency was numerically designed and analyzed, fabricated, and validated experimentally. We show theoretically that the quantum-efficiency spectrum broadens because of anomalous dispersion of the reflection phase of a mirror in the device and describe conditions that allow maximal flatness of the transmitted spectrum to be achieved. To demonstrate the concepts we design, fabricate, and characterize a backilluminated In_0.47 Ga_0.53 As-based p-i-n photodiode upon a InP substrate. Experimental measurements of the fabricated devices demonstrate a peak quantum efficiency of 0.80 at 1550 nm and a FWHM of transmittance of 35.96 nm.