A Geiger mode planar InGaAs/InP avalanche photodiode （APD） with a cascade peripheral junction structure to suppress edge breakdowns is designed by finite-element analysis. The photodiode breakdown voltage is reduced to 54.3V by controlling the central junction depth, while the electric field distribution along the device central axis is controlled by adjusting doping level and thickness of the lnP field control layer. Using a cascade junction structure at the periphery of the active area, premature edge breakdowns are effectively suppressed. The simulations show that the quadra-cascade structure is a good trade-off between suppression performance and fabrication complexity, with a reduced peak electric field of 5.2 × 10^5 kV/cm and a maximum hole ionization integral of 1. 201. Work presented in this paper provides an effective way to design high performance photon counting InGaAs/InP avalanche photodiodes.
A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode （Geiger-mode） single-photon detection are intuitionally demonstrated for the first time. The performance of the detector as a gated-mode single-photon counter at wavelengths of 1310 and 1550nm is investigated. At the operation temperature of 203K,a quantum efficiency of 52% with a dark count probability per gate of 2.4 × 10 ^-3 ,and a gate pulse repetition rate of 50kHz are obtained at 1550nm. The corresponding parameters are 43%, 8.5 × 10^-3 , and 200kHz at 238K.
