High brightness diodes and 600W 62% efficient low SWaP fiber-coupled package

In this paper, we show results of further brightness improvement and power-scaling enabled by both the rise in chip brightness/power and the increase in number of chips coupled into a given numerical aperture. We report a new chip technology using new extra Reduced-mode (x-REM) diode design providing a record ~363 W output from a 2×12 nLIGHT element® in 105 μm diameter fiber. There is also an increasing demand for low size, weight and power-consumption (SWaP) fiber-coupled diodes for compact High Energy Laser (HEL) systems for defense and industrial applications. Using thirty single emitters that were geometricallyand polarization-combined, we have demonstrated 600 watts and 62% efficiency at in 225 μm/0.22 NA fiber resulting in specific mass and volume of 0.44 kg/kW and of 0.5 cm³/W respectively. Furthermore, we have increased the number of chips to forty and increased the output power to 1kW and 52% in the same fiber diameter and numerical aperture. This results in a fiber-coupled package with specific mass and volume of <0.18 kg/kW and <0.27 cm³/W, respectively.