SBIR Phase I: Low Cost High Brightness Photonic Crystal Lasers with Integrated Non-Linear Crystals

该小型企业创新研究（SBIR）第一阶段项目的目标是开发一种在900至1070 nm波长范围内工作的高度相干表面发射光子晶体（SEPC）半导体激光器。需要高亮度激光器来有效地泵浦非线性晶体以获得倍频的绿色（~532 nm）和蓝色（~470 nm）光。最初的原型将在976 nm波长附近工作，以产生488 nm的倍频输出，作为氩离子激光器的替代品。为了实现高亮度，SEPC激光器概念在外延结构内包括反射堆叠，以最大限度地减少由于SE光子晶体的双向外耦合而导致的朝向外延（p侧）金属接触的光损失。倍频SEPC激光器的广泛应用包括投影显示、生物仪器、半导体晶片检测和化学传感。此外，SEPC二极管激光器将直接替代光纤激光器。此外，SEPC激光器阵列将用作高功率激光源，具有高光束质量，适用于包括机械加工、材料加工和医疗应用在内的市场。表面发射使完整的晶圆加工和测试成为可能，由于硅IC工业的规模经济，其优点允许提高可靠性和显着降低成本。表面发射还消除了对刻面涂层的需要，并防止灾难性的光学损伤（COD）以及刻面退化。因此，这种SEPC器件具有极低成本和接近50%的电光效率的潜力。与用于泵浦应用的常规宽面积二极管激光器相比，具有高相干、高亮度、单瓣远场的单频操作提供了额外的有效效率。此外，SEPC激光器的输出孔径尺寸可以被设计成在没有外部光学器件的情况下产生圆形输出光束，从而进一步降低激光器封装的成本。

This Small Business Innovation Research (SBIR) Phase I project goal is to develop a highly coherent surface-emitting photonic crystal (SEPC) semiconductor laser operating in the 900 to 1070 nm wavelength range. High brightness lasers are required to efficiently pump non-linear crystals to obtain frequency doubled green (~532 nm) and blue (~470 nm) light. Initial prototypes will operate around wavelength of 976 nm to produce frequency doubled output at 488 nm as replacement for argon-ion lasers. To achieve high brightness the SEPC laser concept includes within the epitaxial structure a reflecting stack to minimize loss of light towards the epitaxial (p-side) metal contact caused by the bi-directional outcoupling of the SE photonic crystal.A broad set of applications for the frequency-doubled SEPC lasers include projection display, bioinstrumentation, semiconductor wafer inspection and chemical sensing. In addition, SEPC diode lasers will find application as direct replacement for fiber lasers. Furthermore, arrays of SEPC lasers will be used as high power laser sources with high beam quality in markets that include machining, material processing, and medical applications. Surface-emission makes possible complete wafer processing and testing, advantages that permitted improved reliability and significant reductions in cost due to the economy of scale for the silicon IC industry. Surface emission also eliminates the need for facet coating and prevents catastrophic optical damage (COD) as well as facet degradation. As a result, this SEPC device has potential for extremely low cost and electrical to optical efficiencies approaching 50%. The single frequency operation with a highly coherent, high brightness, single-lobe far-field provides an additional effective efficiency compared to conventional broad area diode lasers for pump applications. In addition, the output aperture size of the SEPC laser can be engineered to produce circular output beam without external optics further reducing the cost of the laser package.