Transient thermal analysis of semiconductor diode lasers under pulsed operation

Abstract

Self-heating in semiconductor lasers is often assumed negligible during pulsed operation, provided the pulses are ‘short’. However, there is no consensus on the upper limit of pulse width for a given device to avoid-self heating. In this paper, we present an experimental and theoretical analysis of the effect of pulse width on laser characteristics. First, a measurement method is introduced to study thermal transients of edge-emitting lasers during pulsed operation. This method can also be applied to lasers that do not operate in continuous-wave mode. Secondly, an analytical thermal model is presented which is used to fit the experimental data to extract important parameters for thermal analysis. Although commercial numerical tools are available for such transient analyses, this model is more suitable for parameter extraction due to its analytical nature. Thirdly, to validate this approach, it was used to study a GaSb-based inter-band laser and an InP-based quantum cascade laser (QCL). The maximum pulse-width for less than 5% error in the measured threshold currents was determined to be 200 and 25 ns for the GaSb-based laser and QCL, respectively.

Thermal Simulation and Experimental Analysis of Optically Pumped InP-on-Si Micro- and Nanocavity Lasers

“…More recently, thermal effects of InP/InAs nanowire lasers integrated on different optical platforms were studied and results revealed that decreasing the thermal resistance between the nanowires and substrates is the most efficient way for cw nanowire laser operation . There are also few studies focusing on the transient thermal effects in semiconductor lasers. , Size scalability of micro- and nanocavity lasers is another important consideration as wavelength- and sub-wavelength scale lasers have been pursued to realize smaller footprints, lower lasing thresholds, and higher modulation speeds, giving rise to non-classical phenomena which are hardly seen in conventional resonators, such as the Purcell effect (enhancement of the spontaneous emission rate) and high β-factor (spontaneous emission coupling to the lasing mode). − Furthermore, size scaling leads to an increased effect of thermal interfaces that needs to be taken into account.…”

Thermal analysis and heat dissipation improvement for quantum cascade lasers through experiments, simulations, and structure function

“…Veerabathran et al measured the thermal resistance by inputting a pulsed power to a QCL, which is called dynamic mode measurement. 21) On the other hand, as a new method of thermal analysis for semiconductors, a structure function was proposed, in which the heat dissipation path from the heat source to the surrounding environment was expressed in terms of thermal resistance and thermal capacity. 22) Székely proposed the use of the static mode for transient heat measurement and reported experimental results on obtaining the structure function using the static mode.…”