This SBIR project will develop and deliver revolutionary driver technology with intelligent fault protection for driving long-pulse (> 2msec), quasi-CW laser diode arrays (LDAs) at high power with improved performance and lifetime. A critical issue with operating LDAs for long discharge pulses is localized diode heating leads to current and optical instabilities, which irrevocably damage emitters resulting in LDA failure. SRL has demonstrated that diode instabilities can be detected and eliminated. As a result, integrating SRL's proprietary fault diagnostics into diode drivers increases laser diode lifetimes by more than a factor-of-40 over unprotected drivers. In addition, in Phase 1, SRL will acquire data demonstrating that our fault-mode circuitry can be used as a diagnostic to a priory determine which LDA's will have long lifetimes. In Phase 2 we will deliver a fully engineered compact driver for powering NASA LDAs and screening their suitability for use in flight hardware. The Phase 2 driver will have specific power ratings up to 7 kW/liter, which is 4 times higher than existing laser diode drivers. The combination of fault diagnostics for increased laser diode performance and lifetime and compact packaging, makes the SRL driver an important technology for powering LDAs for NASA flight systems.