High-power broad-area diode lasers for laser cooling

This work describes an experimental investigation on the applicability of an injection-locked broad-area diode laser for laser cooling, which requires narrow-linewidth light. Unlike diode laser arrays, injection locked broad-area lasers have so far not been demonstrated to operate on a linewidth below 1 MHz. Using a heterodyne technique, we show that the frequency of the master laser is tracked by the locked broad-area laser to within 2 kHz. This implies that when a narrow-linewidth laser is used as a master, an equally narrow-linewidth output can be obtained. Furthermore, we investigated practical aspects like ease of alignment, and tuning behavior. We conclude that an injection-locked broad-area laser can be an excellent laser source for applications requiring high-power narrow-linewidth laser light, like non-linear spectroscopy and laser cooling.