9360378 Tidwell In an effort to reach higher powers, laser researchers have developed larger and increasingly complex devices. An alternate scaling approach is to combine the output power of many simple low-power lasers in an array. Microlasers are the perfect array elements because they are mass-producible and have polarized, singlefrequency, diffraction-limited outputs. Aculight has developed a unique microlaser array based on the desire for coherent operation. A coherent array with N elements produces an output beam that is N times more powerful on a distant target or N times smaller at the focus of a lens than an incoherent N-element array. Since microlaser arrays can easily contain several hundred elements, the benefit of coherent operation is great. Coherent operation opens applications in machining and processing of advanced materials such as composites and ceramics. It also enables applications requiring the output wavelength to be converted to other parts of the spectrum using nonlinear optics. Coherent operation is also the next step toward electronic beam steering for military and commercial applications. These opportunities are possible only with the previous development of the Aculight mircolaser array hardware. The objective of the proposed Phase I program will be to demonstrate coherent operation of the Aculight microlaser array. We will fabricate servo control electronics for the array and integrate the circuitry into the existing computer. We will test the sensitivity of the laser to variations in power, cooling, and other variables to determine the ultimate commercial feasibility. The anticipated result is a compact, scalable laser with high beam quality and single-frequency output.