Broadband (0.1-12 GHz) fiber-optical photoelectric detector with low level of reflected signal for high-speed digital and analog microwave systems of information transfer

This paper presents experimental results of original design of ultrahigh frequency fiber optic InGaAs/InP photodetector for 0.95-1.7 mkm spectral region with high return optical loss. Reflected light in fiber optic link (caused by fiber optic connectors and receiver end-fiber cleaved end, photodiode chip surfaces) can produce output power fluctuation, phase noise, pulse distortion of laser transmitter. Optical discontinuities lead to occurrence of additional optical resonator in fiber optic transmission line and parasitic amplitude modulation of transmitted signal, which decreases S/N or RIN volume. The photo-detector demonstrates return loss as high as 50-55 dB in the wide band (0.1-12 GHz).