A simple and highly reliable laser system with microwave generated repumping light for cold atom experiments

The increasing complexity of cold atom experiments puts ever higher demands on the stability and reliability of its components. We present a laser system for atom cooling experiments, which is extremely reliable yet simple to construct and low-cost, thus forming an ideal basis for ultracold atom experiments such as Bose–Einstein condensation and degenerate Fermi gases. The extended cavity (master) diode and slave lasers remain locked over a period of months with a drift in absolute frequency well below 1 MHz with a line-width of less than 300 kHz. We generate the repumper light by modulating the current of an injection locked slave laser at a frequency of 6.6 GHz. The construction of the laser is simple and largely based on off-the-shelf electronic and optomechanical components.