Theoretical design of high responsivity and high output power sub-THz MUTC-PDs from vertical to waveguide configurations

Abstract

We demonstrate novel configurations for sub-THz modified uni-traveling-carrier photodetectors (MUTC-PDs) with high responsivity and output power, transitioning from vertical to waveguide-based designs. At 100 GHz, the vertical MUTC-PD demonstrates an output power ranging from 8.07 dBm to 14.89 dBm, while at 140 GHz, the output power varies from 5.94 dBm to 13.2 dBm, under bias voltages between 0 V and -2 V. The proposed waveguide MUTC-PD, featuring a 3D configuration with a dimension of 4 μm × 7 μm, achieves a responsivity of 0.79 A/W. This design exhibits a maximum 3-dB bandwidth of 152.83 GHz and a bandwidth efficiency product of 96.58 GHz. The well-optimized sub-THz MUTC-PD operates at low bias voltages, while the transformation from vertical to waveguide configurations offers the flexibility to choose the most suitable photodetector type based on specific requirements. This approach enables optimized performance across various use cases and holds significant potential for applications in the terahertz regime.