Pump Laser Diode Module

The object of this proposal is to demonstrate that flight-hardened laser diode pump modules with superior reliability can be produced by use of advanced composite materials and proven high-reliability packaging methods. Our approach relies on use of novel metal matrix composites (MMC), such as aluminum silicon carbide (AlSiC), that combine superior mechanical properties of ceramics with high heat conductivity of CVD diamond. We show that using new processing techniques developed at PD-LD, Inc. these materials can be prepared for direct die bonding with no less success than regular metal substrates. Using proper package design can reduce the thermal resistance to the die by 70% XX over conventional high-power laser diode packages. As a result, laser junction temperature can be reduced by 20 to 30 C in otherwise identical operating conditions. Such reduction in junction temperature alone is sufficient to increase the expected laser lifetime by close to an order of magnitude. Judicious attention to die mounting and optics mounting techniques is also necessary to avoid premature laser failures.