Metal-semiconductor-metal photodetectors of finger spacing and width as small as 100 nm have been fabricated on bulk and low-temperature grown GaAs, and tested using a femtosecond pulse laser and high-speed electro-optic sampling. The fastest photodetectors have a measured full width at half maximum impulse response and a 3-dB bandwidth of 0.87 ps and 510 GHz, respectively, for low-temperature grown GaAs limited by carrier recombination time; and of 1.5 ps and 295 GHz for bulk GaAs, limited by the RC time constant. To our knowledge, they are the fastest detectors of their kinds reported to date.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)