Wavelength tunable tapered diode lasers at 1180 nm with high spectral radiance

GaAs-based semiconductor structures for laser emission at 1180 nm are challenging due to the quantum well strain required. However, significant progress has been made in recent years, in particular through the development of a highly efficient asymmetric epitaxial layer structure for a super-large optical resonator. In 2024, reliable emission of more than 7 W at 1180 nm from a distributed Bragg reflector tapered diode lasers (DBR-TPL) was reported. That enables the use of these laser devices for frequency doubling to 590 nm in order to address medical applications, the manipulating of sodium ions or fluorescence spectroscopy. In this paper, we will recap the development of DBR-TPL emitting at 1180 nm as well as featuring high spectral radiance and reliability. We will show the concept, technological details as well as electro-optical properties and discuss the possibility to tune the wavelength via grating period, injection current, temperature and a resistive DBR-grating heater. Therefore, spectral investigation will be shown and discussed in detail.