Characteristics of thermal drift of the emission frequency of a stripe-geometry semiconductor laser

An investigation was made of tuning of the emission frequency of a stripe-geometry semiconductor laser as a result of heating of the active region during a pump pulse or when the pump current was varied. It was found that the rate of thermal drift of the emission frequency of a stripe-geometry laser changes abruptly on transition from lasing in one transverse mode to lasing in another. It is shown that as the pump current increases, the frequency can either increase or decrease and, for a certain current, the rate of frequency tuning may fall to zero. These characteristics are due to the waveguide confinement of the field in the active region of a semiconductor laser.