A long-wavelength, annular In0.53Ga0.47As p-i-n photodetector

We describe a novel, annular In 0.53 Ga 0.47 As p-in photodiode sensitive to λ = 1.7 µm for use as a fiber tap or front-face laser monitor. The diode has a 150 µm diameter, straight-walled hole through the diode cross-section formed by photochemical etching. The hole is concentric with the 430 µm diameter mesa. A dark current of I = 90 nA at 5 V and a breakdown voltage of 33 V indicate that the hole formation process does not result in significant degradation of the device operating characteristics. Measurements of photoresponse as a function of position across the diode surface give further evidence that the hole does not effect overall device performance.