High-Speed Mid-Wave Infrared Uni-Traveling Carrier Photodetector Based on InAs/InAsSb Type-II Superlattice

High-speed photodetectors operating at mid-wave infrared are crucial for free-space optical communication and frequency comb spectroscopy. In this letter, we report a high-speed mid-wave infrared uni-traveling carrier photodiode based on InAs/InAsSb type-II superlattice at room temperature for the first time. The device exhibits a cut-off wavelength of around 5.5
$\mu \text{m}$
at room temperature. The responsivity of the device is about 0.6 A/W (at 4.5
$\mu \text{m}$
) under −1 V at room temperature. The frequency response of the device is characterized by an optical parametric amplification system generating mid-infrared femtosecond pulses. A device with a 20
$\mu \text{m}$
diameter has a 3-dB bandwidth of 12.8 GHz at −4 V. These promising results suggest that the device could be potential candidates to be employed in the emerging high-speed MWIR applications.