Temperature Compensation for Threshold Current and Slope Efficiency of 1.3µm InAs/GaAs Quantum-Dot Lasers by Facet Coating Design

We demonstrate a technique of temperature compensation for 1.3 µm InAs/GaAs quantum-dot (QD) lasers by facet coating design. The key point of the technique is to make sure that the mirror loss of the lasers decreases as the temperature rises. To realize this, we design a type of facet coating by shifting the central wavelength of the facet coating from 1310 nm to 1480 nm, whose reflectivity increases as the emission wavelength of the lasers red-shifts. Consequently, the laser with the new facet coating exhibits a characteristic temperature doubled in size and a more stable slope efficiency in the temperature range from 10°C to 70°C, compared with the traditional one with a temperature-independent mirror loss.