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

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.