Photonic crystal surface emitting semiconductor laser

Surface-emitting lasers (SEL) are advantageous for high power laser applications due to their unique properties of circular beams, the absence of catastrophic optical damage (COD), and their suitability for 2D integration for power scaling. Ideally, these lasers should be monolithic, electrically pumped (EP), with single mode emission and close to diffraction limited optical beam output. Recently it has been discovered that high quality-factor (Q-factor) cavities can be achieved through the use of a single defect-free photonic crystal (PC) slab which is evanescently coupled to a neighboring gain region. In these devices, coined photonic crystal surface-emitting lasers (PCSELs), the lasing state corresponds to a single, high-Q point in the PC band structure which exists above the light line. Due to the lateral cavity size scalability, high power single mode large area PCSELs are possible with high brightness and diffraction limited beams. Since the principle of the PCSEL can be applied to all frequency ranges of electromagnetics, it is feasible to scale the wavelengths from deep UV all the way to midwave- and far- infrared (MWIR, FIR) and THz. Many different material systems can be explored for high power laser applications. The objective of this SBIR Phase I project is to formulate the trade-space towards the design and development of high-power high-beam quality photonic crystal surface emitting laser (PCSEL) through a modeling and simulation (M&S) approach. The simulation tool consists of four different modules for the electrical, optical, and mechanical designs of PCSELs at high power levels. The model will also be validated with experimental development.  By the end of Phase I base period, we will complete PCSEL modeling and simulation (M&S) tool which include four major modules. The tool is capable of design of PCSELs from visible to infrared based on at least two or three different material systems (GaAs, InP, GaSb). The tool is also capable of PCSEL performance evaluations in terms of threshold current, output power, efficiency, beam quality, and thermal management, etc. By the end of Phase I option period, we will have at least one (or two) PCSEL  designs based on InP and/or GaSb materials, depending on the feedback and request from the Army. We will also carry out some preliminary experiments by completing one set of devices runs, from material growth and regrowth, to device fabrication and characterization. A Phase II proposal will also be submitted during this period. By end of Phase II, PCSEL prototypes will be delivered in a package considering thermal management for evaluations on laser mode quality, coherence, efficiencies, thermal stability, etc.