Analysis On The Thermal Characteristics Of High Power Semiconductor Lasers

Semiconductor lasers are optoelectronic devices with great potential in the laser industry.With the increasing output power of semiconductor lasers,the thermal management of semiconductor lasers has become a hot spot and a difficult point for researchers.Therefore,it is of great significance to analyze and optimize the thermal characteristics of semiconductor lasers in the semiconductor laser industry.The main research contents of this paper are as follows::The steady-state thermal characteristics of the semiconductor laser are analyzed by ANSYS.The related formula of the thermal lens effect of the semiconductor laser is proposed and deduced.Besides,the influence of the focal length of the equivalent thermal lens and the thermal effect on the divergence angle of the slow-axis beam is quantitatively calculated.The junction temperature and slow-axis divergence angle of packaged laser are measured by experiments,and the difference between divergence and simulation results is compared.The analysis shows that the thermal lens effect becomes obvious with the increase of thermal power,which is,with the increase of thermal power,the focal length of thermal lens decreases and the divergence angle of slow-axis beam increases.The transient thermal characteristics of semiconductor lasers are analyzed by ANSYS.The effects of current pulse width,pulse period and duty cycle on the temperature rise in the active region of semiconductor lasers are analyzed.The equivalent thermal expansion coefficient and equivalent thermal conductivity of Cu/AlN/Cu and Cu/SiC/Cu multilayer heat sinks are calculated by ANSYS finite element analysis,and the variation trend of these parameters is analyzed by changing the thickness of Cu.The effects of heat sink on the packaging of semiconductor lasers are also analyzed.The reliability of the wide strip semiconductor laser packaged in AlN heat sink is preliminarily tested and evaluated.The tests show that the estimated lifetime is about 30812 hours at a heat sink temperature of 25? and an operating current of 19 A.