  High speed mid-wave infrared (MWIR) photodetectors have applications in the
areas such as free space optical communication and frequency comb spectroscopy.
However, most of the research on the MWIR photodetectors is focused on how to
increase the quantum efficiency and reduce the dark current, in order to
improve the detectivity (D*), and the 3dB bandwidth performance of the
corresponding MWIR photodetectors is still not fully studied. In this work, we
report and characterize a MWIR interband cascade photodetector based on
InAs/GaSb type-II superlattice with a 50% cutoff wavelength at ~5.3 um at 300
K. The 3 dB cutoff frequency is 2.4 GHz at 300 K, for a 40 {\mu}m circular
diameter device under -5 V applied bias. Limitations on the detector high speed
performance are also discussed.High speed mid-wave infrared (MWIR)
photodetectors have applications in the areas such as free space optical
communication and frequency comb spectroscopy. However, most of the research on
the MWIR photodetectors is focused on how to increase the quantum efficiency
and reduce the dark current, in order to improve the detectivity (D*), and the
3dB bandwidth performance of the corresponding MWIR photodetectors is still not
fully studied. In this work, we report and characterize a MWIR interband
cascade photodetector based on InAs/GaSb type-II superlattice with a 50% cutoff
wavelength at ~5.3 um at 300 K. The 3 dB cutoff frequency is 2.4 GHz at 300 K,
for a 40 um circular diameter device under -5 V applied bias. Limitations on
the detector high speed performance are also discussed.
