Femtosecond-Laser-Based Welding for the Fabrication and Integration of Lidar Lasers

This proposal innovates an ultrafast laser welding (UFLW) system and processes that provide epoxy-free bonding of optical and mechanical components suitable for lidar sources in the space environment. This proposal responds to SBIR subtopic S1.01 Lidar Remote Sensing Technologies, aiming at improving instrumentsrsquo; compactness, reliability, lifetime, and long-term performance. It will develop the UFLW technology from the theoretical and experimental standpoints with three objectives: (I) Theoretically investigate the physical mechanism of UFLW to predict weld geometry and thermal stress. (II)Experimentally investigate the impact of focusing conditions and inter-substrate gap height on weld geometry and bond strength. (III) Demonstrate effective UFLW of glass-to-glass/crystal and glass/crystal to metal. The simulations on ultrafast laser propagation, nonlinear absorption, plasma generation, heat accumulation, and melt zone formation will be conducted, predicting welding geometry. The effect of focusing conditions, scanning speed, and gap height on weld geometry and bond strength will be experimentally investigated. Optimum processing parameters for bonding the proposed glass/metal/crystal materials will be determined. Bond strength and weld geometry will be characterized and reported. UFLW will enable monolithic lasers and increase the integrity and durability of space-borne instruments. It will also benefit commercial sensors and advance very high Speed datacom amp; communications links via advanced electronics/photonics integration. The success of this project has high potential to enable the US to become the international leader of the emerging digital manufacturing sector enabled by ultrafast lasers. The offeror, Aktiwave LLC, is exceptionally well aligned with the goals and aspirations of the SBIR program, possessing leading expertise and capability in lasers and ultrafast-laser-based welding, polishing and structuring of optical materials.