Record High-Temperature Long-Pulse Operation of 8xx-nm Diode Laser Bar with Aluminum-Free Active Region

We report on the first demonstration of long-pulse (milliseconds) operation of aluminum-free active-region 8xx-nm diode laser bar at heat-sink temperature of 180 °C. This is, to the best of our knowledge, the highest published operating temperature for a long-pulse 8xx-nm laser bar with Al-free active region. The laser bars have very robust performance at 130 °C without any active cooling. At this high temperature, the laser bars provide both high peak power (60 W at 100 A) and good pulse shape for tens of milliseconds pulse width, maintaining high energy per pulse. The dependence of laser output pulse shape on the pulse width and pump current is experimentally investigated at 130 °C. We find that the transient output power of the laser bar follows P(t) = A exp(-t /t₀) + Bt + C, where A, B, C, and t ₀ are fitting parameters that are pulse width and current dependent. We have also investigated the transient thermal behavior of the laser bar at high temperature and high pump current.