Compact, High Intensity, Low Cost, Free Standing Illumination Sources

The Army needs high power light sources for high speed photography. The cameras with frame rates of million frames/sec are increasingly being used for recording of fast events such as the impact of an explosion on an MRAP(Mine Resistant Ambush Protected) vehicle. Princeton Optronics proposes a solid-sate IR laser illuminator design based on the VCSEL (Vertical Cavity Surface Emitting Laser) technology to record such events. In phase I of the SBIR we developed an illuminator to demonstrate the feasibility of developing a compact, high intensity illuminator using VCSEL technology. We propose to develop a low cost and free standing illumination source emitting>2kW total power around 808nm in phase II. Its unique design, packaging and output laser beam would satisfy the Army requirements for application of MRAP vehicle illumination. The package design developed for the phase I prototype will be scaled up for the phase II higher power prototype. We have also performed the design optimization in terms of VCSEL chip size, the number of VCSEL chips, beam delivery optics and thermal management, etc. We have completed the fabrication and demonstration of the illuminator prototype. The output beam shows a uniform light intensity distribution and divergence of 82 degree full angle. The prototype is capable delivering over 150W of power at room temperature (~20C) and over 100W at the elevated temperature (46C). The performance exceeds the Army"s power specification of 70W for the early version of the prototype. In Phase II, we will complete the design and fabrication of the illuminator as well as its battery powered control and driver circuit. We will develop a novel high gain quantum well technology for the VCSELs arrays to be used in the illuminator to improve its power performances. We will also deploy a new method of thermal management to efficiently dissipate the heat. At the end of Phase II project, a live demonstration will be performed at Army testing facility. The illuminator will be operated at Army specified conditions to enable high speed filming at 1us exposure.