Abstract

Low-temperature-grown GaAs (LTG-GaAs) based photodetectors (PDs) merit a lot of attentions due to their short response lime, high electrical bandwidth, high output saturation current, and low dark current. However the wide absorption band gap (~800 nm) of LTG-GaAs restricts its applications from long wavelength (1300 ~ 1550 nm) optical communications. Recently, several research groups had demonstrated LTG-GaAs based p-i-n, MSM PDs^1,2 in this wavelength regime by utilizing mid-gap defect stale to conduction band transitions. However, these PDs usually suffered extremely low quantum efficiency (~0.6 mA/W)² or serious electrical bandwidth degradation due to long device absorption length for higher saturation power¹ and quantum efficiency purpose. In this paper, we demonstrated ultrahigh speed and high saturation power performances of ITG-GaAs based MSM TWPD in the telecommunication wavelength regime (~1300 nm). Due to short carrier trapping time of ITG-GaAs layer and superior microwave guiding structure in MSM TWPD, record ultra-high peak power bandwidth product performance has been obtained in long absorption length devices.

© 2002 Optical Society of America