我們展示了一種新型具有高功率性能在THz regime的超快速光偵測器（PD）。藉由基於在InP的單載子傳輸光偵測器（UTC-PD）結構中使用type-II GaAs0.5Sb0.5（p）/ In0.53Ga0.47As（i）混合吸收層，其響應性可以被提升由於窄帶隙和光吸收過程的增強在type-II界面的GaAs0.5Sb0.5和In0.53Ga0.47As吸收層之間。此外，電流阻塞效應通常是UTC-PD輸出功率的主要限制因素之一，但在這裡可以被忽略，由於從GaAs0.5Sb0.5層到InP based collector被注入光電子的過剩能量。覆晶式鍵合封裝在3 m直徑的主動區元件，顯示適當響應度（0.11A / W）和記錄寬的3dB optical-to-electrical（OE）帶寬為0.33THz，以上所量測的波長在長波長（ 1.3-1.55 m）PDs。在具有正弦的光信號和PD激發的〜63％調製深度下，在0.32THz的工作頻率下，13mA的飽和電流和連續波（CW）輸出功率高達-3dBm。;We demonstrate a novel type of ultra-fast photodiode (PD) with high-power performance at THz regime. By using type-II GaAs0.5Sb0.5 (p)/In0.53Ga0.47As (i) hybrid absorber in a InP based uni-traveling carrier photodiode (UTC-PD) structure, its responsivity can be improved due to the narrowing of bandgap and an enhancement of photo-absorption process at the type-II interface between GaAs0.5Sb0.5 and In0.53Ga0.47As absorption layers. Furthermore, the current blocking effect, which is usually one of the major limiting factors in output power from UTC-PDs, can be minimized due to the high-excess energy of photo-generated electron injected from GaAs0.5Sb0.5 layer to InP based collector. The flip-chip bonding packaged device with a 3 um active diameter shows a moderate responsivity (0.11 A/W) and a record wide 3-dB optical-to-electrical (O-E) bandwidth as 0.33 THz among all the reported long wavelengths (1.3-1.55 um) PDs. Under the optical signal with a sinusoidal envelope and a ~63% modulation depth for PD excitation, a 13 mA saturation current and a continuous wave (CW) output power as high as -3 dBm at an operating frequency of 0.32 THz is successfully demonstrated.
