High-performance 1.55 μm low-temperature-grown GaAs resonant-cavity-enhanced photodetector

摘要

A 1.55 μm low-temperature-grown GaAs (LT-GaAs) photodetector with a resonant-cavity-enhanced structure was designed and fabricated. A LT-GaAs layer grown at 200℃ was used as the absorption layer. Twenty- and fifteen-pair GaAs/AlAs-distributed Bragg reflectors were grown as the bottom and top mirrors. A responsivity of 7.1 mA/W with a full width at half maximum of 4 nm was obtained at 1.61 μm. The dark current densities are 1.28 X 10~(-7) A/cm~2 at the bias of 0 V and 3.5 X 10~(-5) A/cm~2 at the reverse bias of 4.0 V. The transient response measurement showed that the photocarrier lifetime in LT-GaAs is 220 fs.