Cascade Uni-Traveling-Carrier Photodetector Array for Terahertz Applications

A cascade array structure and depleted layer thickness design method of uni-traveling-carrier photodetector (UTC-PD) for terahertz applications is proposed. The cascade array structure can increase the 3dB bandwidth from 203 GHz to 255 GHz compared to the high-speed single UTC-PD with a diameter of 3 mu m by effectively reducing the overall device capacitance. The 3dB bandwidth can be further improved to 267 GHz by thickness optimization. The combination of cascade array structure and depleted layer thickness optimization can significantly improve the saturation output power of the device at 100, 200 and 300 GHz, which enables the design of cascade UTC-PD array to be applied in terahertz (THz) band.

Automated summary

A cascade array structure and depleted layer thickness design method for terahertz applications of uni-traveling-carrier photodetectors (UTC-PDs) is proposed. The cascade array structure effectively reduces overall device capacitance and increases the 3dB bandwidth from 203 GHz to 255 GHz, compared to a high-speed single UTC-PD with a diameter of 3 μm. Further improvement to 267 GHz is achieved through thickness optimization. The combination of cascade array structure and depleted layer thickness optimization significantly improves the saturation output power of the device at 100, 200, and 300 GHz, enabling the design of cascade UTC-PD array for terahertz band applications.