High-Efficiency And High-Reliability 9xx-Nm Bars And Riber-Coupled Devices At Coherent

Ongoing optimization of epitaxial design within Coherent device engineering has led to a family of high power-conversion-efficiency (PCE) products on conductively cooled packages (CCP) and fiber array packages (FA-P). At a 25 degrees C heat sink temperature, the PCE was measured at 71.5% with 75W CW output power on 30% fill-factor (FF) bars with passive cooling. At heat sink temperatures as high as 60 degrees C the PCE of these bars is still maintained above 60%. Powered by such high efficiency 9xx nm diodes, Coherent FAP products have consistently exceeded 55% PCE up to 50W power levels, with 62% PCE demonstrated out of the fiber.High linear-power-density (LPD) operation of 100 mu m x 7-ernitter bars at LPD = 80 mW/mu m was also demonstrated. Bars with 7-emitter were measured up to 140W QCW power before catastrophic optical mirror damage (COMD) occurred, which corresponds to a COMD value of 200mW/mu m or 2D facet power density of 29.4 MW/cm(2). Leveraging these improvements has enabled high power FAPs with > 90W CW from an 800 mu m-diameter fiber bundle.Extensive reliability testing has already accumulated 400,000 total real-time device hours at a variety of accelerated and non-accelerated operating conditions. A random failure rate < 0.5% per kilo-hours and gradual degradation rate < 0.4% per kilo-hours have been observed. For a 30% FF 50W CW 9xx nm bar, this equates to > 30,000 hours of median lifetime at a 90% confidence level. More optimized 30% FF 9xx nm bars are under development for power outputs up to 80W CW with extrapolated median lifetimes greater than 20,000 hours.