Wavelength tuning of type-II “W” quantum well of interband cascade laser

We report the wavelength tuning of type-II “W” quantum well of interband cascade laser. By changing the thickness of the InAs electron well, the wavelength of the active region is adjusted. We found that the whole 3-4 μm spectra can be realized and the intensity was basically the same by measuring the photoluminescence (PL) of the active region. It showed that the type-II “W” quantum well of interband cascade laser can achieve 3-4 μm range without attenuation. In addition, we calculated the wavelength of quantum well of different InAs thickness by the 8-band k·p method. And we found that the wavelength of the active region varies with the thickness of the InAs electron well, which is consistent with the theory. In addition, the measured wavelength was different from the theoretical wavelength, which may be due to the As incorporation. The incorporation of As into the InGaSb layer will lead to blue shift in the wavelength.