Dilute nitride resonant cavity enhanced photodetector with internal gain for the λ ∼ 1.3 μm optical communications window

We report on a novel dilute nitride-based resonant cavity enhanced photodetector (RCEPD) operating at 1.286 μm. The RCEPD was fabricated using 21 pairs top and 24 pairs bottom GaAs/AlGaAs distributed Bragg reflectors for mirrors and 7 nm thick nine GaAs/Ga 0.65 In 0.35 N 0.02 As 0.98 quantum wells as the absorption region. For a 15 μm diameter window, the photocurrent at 1.286 μm is 27 μA and 42 μA, at V = 0 and −1 V, respectively, whereas the dark current is as low as 1.7 nA at −1 V. At the operating wavelength, an excellent wavelength selectivity with a full width at half maximum (FWHM) of 5 nm, and a high quantum efficiency of 43% are demonstrated. The device exhibits significant internal gain at very small reverse bias voltages of V ⩾ −2 V with an overall quantum efficiency of 67%. These are the best ever recorded values for a dilute nitride RCEPD.