External Cavity Mid-Infrared Semiconductor Lasers

Sb mid-IR laser can be used in external configuration to achieve wide wavelength tuning range. At low temperature, gain media with band-edge wavelengths between 3.3 to 4 pm have been demonstrated with wavelength tuning up to ∼9% of the center wavelength. Power output from few tens of mW to 0.2-W peak, 20-mW average was achieved. Type-II Sb laser promises the possibility of such performance at higher temperature, e. g. 200 K. However, significant trade-off must be considered between tuning range and power and efficiency. Optimization requires consideration of both basic wafer design and cavity geometry.