An 850 nm InGaAs Modified Uni-Traveling-Carrier Photodiode Enhanced by Distributed Bragg Reflector

We report an 850 nm surface-illuminated InGaAs modified uni-travelling-carrier photodiode (MUTC-PD) with distributed Bragg reflector (DBR) bottom mirror. By adopting InGaAs as the absorber, which exhibits a higher absorption coefficient than GaAs, the absorption layer thickness can be reduced to 960 nm, so as to minimize the transit time of the photogenerated carriers. The fabricated MUTC-PD demonstrates a 3-dB bandwidth of 27.5 GHz and a responsivity of 0.51 A/W under a bias of -2 V at the wavelength of 850 nm.