SBIR Phase II: Strained Layer Avalanche Photodiodes for Long Wavelength Applications

Olsen小型企业创新研究第二阶段项目将设计、优化并交付一种高性能雪崩光电二极管（APD），用于1.0-2.2 um光谱区域，作为高性能电信和激光雷达接收器。应变外延层将与多量子阱（MQW） InGaAsP/InP层结合。应变层扭曲了倍增（增益）区的价带，以减小发生电离的场。这降低了器件的工作电压，也降低了空穴/电子电离系数的比率（与非应变情况相比），从而降低了噪声。在第一阶段，设备被制作并测试了拉伸和压缩应变。测量到的雪崩增益为100，空穴/电子增益比为0.2-0.4，最终证明了概念的可行性。第二阶段将制造和优化一个可靠的平面结构，光响应到1.65 um，实现低电压（10-20v），低噪声工作，高增益（50）和高良率的优点。然后，这些概念将应用于InAsP/InGaAs材料系统，以及使用三元InAsP基板，以实现2.2um的低噪声雪崩增益。该项目将产生高性能、低成本、用于光纤通信、人眼安全测距和光谱的红外探测器。该装置也适用于波长超过2微米的设备，这将开辟其他商业可能性，如气体传感和风切变检测。由于apd的高噪声特性，目前在商用长波长光纤通信系统中尚未得到广泛应用。第二阶段计划的成功完成将使低噪音设备商业化，从而打开市场，目前估计每年超过5000万美元。＊＊＊

*** 9629778 Olsen This Small Business Innovation Research Phase II project will design, optimize, and deliver a high-performance avalanche photodiode (APD) for use in the 1.0-2.2 um spectral region as a high performance telecommunications and LIDAR receiver. Strained epitaxial layers will be combined with multi-quantum-well (MQW) InGaAsP/InP layers. The strained layer distorts the valence band of the multiplying (gain) region to reduce the field at which ionization occurs. This reduces device operating voltage and also decreases the ratio of hole/electron ionization coefficients (compared to the unstrained case), and thus decreases noise. In Phase I devices were fabricated and tested with tensile and compressive strain. Feasibility of concept was conclusively demonstrated with measured avalanche gains 100 and hole/electron gain ratios of 0.2-0.4. Phase II will fabricate and optimize a reliable planar structure for light response out to 1.65 um which realizes the advantages of low voltage (10-20v), low noise operation, high gain (50) and high yield. These concepts will then be applied to the InAsP/InGaAs materials system, along with the use of ternary InAsP substrates, to achieve low-noise avalanche gain at 2.2um. The project will result in a high performance, low cost, infrared detector for fiber optic communications, eye-safe range-finding and spectroscopy. This device would also be viable for wavelengths beyond 2 um which would open up other commercial possibilities such as gas sensing and windshear detection. APDs are not yet widely used in commercial long-wavelength fiber optic communication systems because of their high-noise properties. Successful completion of a Phase II program would enable commercialization of a low-noise device which would open up a market, presently estimated at over $50 million per year. ***