Feng Ning-Ning, Dong Po, Zheng Dawei, Liao Shirong, Liang Hong, Shafiiha Roshanak, Feng Dazeng, Li Guoliang, Cunningham John E, Krishnamoorthy Ashok V, Asghari Mehdi
Kotura Inc., 2630 Corporate Place, Monterey Park, CA 91754, USA.
Opt Express. 2010 Jan 4;18(1):96-101. doi: 10.1364/OE.18.000096.
We report a vertical p-i-n thin-film germanium photodetector integrated on 3microm thick large core silicon-on-insulator (SOI) waveguides. The device demonstrates very high external responsivity due to the low fiber coupling loss to the large core waveguides. The germanium width and thickness are carefully designed to achieve high responsivity yet retain high-speed performance. Even with fiber coupling loss included, the device has demonstrated greater than 0.7A/W external responsivity at 1550nm for TM polarization and 0.5A/W for TE polarization. A low dark current of 0.2microA at -0.5V bias is reported. 3dB bandwidths of 12GHz and 8.3GHz at -2.5V bias are also reported for 100microm and 200microm long devices, respectively. The device can cover the communication wavelength spectrum up to 1620nm with a relatively flat responsivity of >0.5A/W. Further studies suggest that with a modified design the device is capable of achieving 1A/W external responsivity for both TE and TM polarizations and greater than 30GHz bandwidth.
我们报道了一种集成在3微米厚的大芯绝缘体上硅（SOI）波导上的垂直p-i-n薄膜锗光电探测器。由于与大芯波导的光纤耦合损耗低，该器件表现出非常高的外部响应度。锗的宽度和厚度经过精心设计，以实现高响应度并保持高速性能。即使包括光纤耦合损耗，该器件在1550nm处对于TM偏振的外部响应度也已证明大于0.7A/W，对于TE偏振为0.5A/W。据报道，在-0.5V偏压下暗电流低至0.2μA。对于100微米和200微米长的器件，在-2.5V偏压下的3dB带宽分别为12GHz和8.3GHz。该器件能够覆盖高达1620nm的通信波长光谱，响应度相对平坦，大于0.5A/W。进一步的研究表明，通过改进设计，该器件能够实现TE和TM偏振的1A/W外部响应度以及大于30GHz的带宽。
