Bias dependent nonlinear responses of LTG-GaAs based p-i-n/n-i-n traveling-wave photodetectors under long wavelength excitation

Summary form only given. The application of LTG-GaAs based photodetectors at communication wavelength (1.3/spl sim/1.55 /spl mu/m) attracts lots of attentions due to their high speed high saturation power performances as well as its capability of integration with mature GaAs-based high speed IC technology. Recently, Chiu et al. had demonstrated the high-speed/high-sensitivity LTG-GaAs based n-i-n/p-i-n traveling-wave photodetectors (TWPDs) in the long wavelength (1.3-1.55 /spl mu/m) regime with high saturation power performance. In this paper, we report the observation of interesting new single-carrier-type photocurrent behaviors in these novel photodetectors under long wavelength excitation. Under high bias and long wavelength (/spl sim/1300 nm) excitation, strong nonlinear responses both in transit state (impulse response) and steady state (DC photocurrent) are observed. These interesting nonlinear behaviors open a new way in the application of photomixing devices.