Development and spectral characterisation of ridge DFB laser diodes for Cs optical pumping at 894 nm

Optical pumping on the cesium (Cs) D1 transition at 894 nm, as compared to the Cs D2 line at 852 nm, can present advantages for e.g. Cs thermal beam atomic clocks or other atom-based sensors and instrumentation, due to its simpler hyperfine structure, larger atomic level splitting, and absence of cycling transitions. Here we report on the realisation and spectral characterisation of custom-made narrow-band DFB laser diodes emitting at 894 nm.