Method of continuous tuning in certain types of semiconductor lasers

One of the main disadvantages of free-running semiconductor lasers in spectroscopy is gaps in their tuning ranges. Due to these gaps only part (about 30%) of the spectrum can be covered in a typical temperature tuning. A method of avoiding such gaps in a multiple quantum well type STC LT50A-03U laser is reported in this contribution. One can expect that the results may be extended to the whole class of MQW lasers. In other types of diode lasers spectrum coverage of about 45% (instead of typical 30%) can be obtained in the proposed way. Furthermore, a qualitative relationship between wavelengths available this way and parameters of a laser junction can be derived within a simple model of mode-hopping behavior.