Coherent Inc., Semiconductor Group, has developed aluminum-free laser diodes that operate at more than 60 °C. These InGaAsP bars, which maintain high electrical-to-optical efficiency, have narrow spectral emission and low beam divergence, making them suitable for diode-pumped solid-state avionics platform lasers and medical and industrial applications. They were tested at 50 W in quasi-continuous-wave mode at 808 nm in temperatures up to 75 °C. Results showed <9% degradation after 109 400-µs pulses at 55 W peak power. At 60 W, the 30% fill-factor bar had a spectral width of 2.2 nm full width half maximum (FWHM) and fast axis beam divergence at <36° FWHM. The company says the advantages of the aluminum-free active area diodes include resistance to dark-line and spot defects, sudden failures, gradual degradation and oxidation.