The need for smaller form factor and more spectrally precise lasers is a basic demand across commercial markets. The key parameter for stable lasers is the linewidth and this is extremely important for sensitive sensing applications such as advance timekeeping and atomic cooling. Many of these sensing applications also require wavelengths operating around 689 nm.
In this paper we report on a stable, single-mode (both transverse and longitudinal), semiconductor laser packaged in a small-form factor 14-pin butterfly package operating at 689 nm wavelength with fibre coupled output power of ∼ 1 mW. We demonstrate for the first time a stable, small form-factor, lightweight, packaged semiconductor laser operating at 689 nm; and this packaged laser enables the use of such devices to create compact sensors in the 689 nm window.