Ultrafast frequency tuning in diode lasers based on InAsSb/InAsSbP heterostructures operating in the 3–4 μm spectral range

We have studied the quality of frequency of tuning in a diode laser based on a double heterostructures of the n -InAsSbP/ n -InAsSb/ p -InAsSbP type driven by short current pulses with positive ramp top. It is established that a monotonic increase in the tuned mode frequency with the time is retained during the first 30-µs-long period of current growth. Then, the dependence of the frequency on the current weakens because of the appearance of nontunable modes. The maximum range of monotonic single-frequency tuning is achieved at a small pulse duration (< 30 μs), which shows prospects for the development of ultrafast-response laser diode spectroscopy.