Heat Dissipation Analysis And Packaging Process Optimization Of Microdisk Cavity Semiconductor Laser

Microdisk cavity semiconductor laser is the combination of optical microcavity and semiconductor laser,it further optimizes the characteristics of small volume,simple structure and light weight of semiconductor laser;The unique Whispering Gallery Mode microdisk cavity further reduces the threshold current of the device and improves the quality factor.We use the active region prepared by quantum cascade material to realize the long wave lasing of micro disk cavity semiconductor laser in the mid far infrared band,especially in the field of toxic gas detection,free space secure communication and other fields have important application value.In this paper,we deeply analyzed the serious thermal effect of long wave lima（?）on microdisk cavity semiconductor laser,on this basis,we introduced a new array inversion packaging structure,improved its thermal characteristics.The details are as follows:1.Based on ANSYS finite element analysis,we simulate the thermal characteristics of micro disk cavity semiconductor lasers in positive and inverted packaging respectively,and deeply studied the distribution of temperature,thermal stress and thermal strain.The results show that:The inverted packaging can effectively reduce the temperature of the active region when the device is working;But it also brings about a significant increase in thermal stress and thermal strain.Due to the natural defects of packaging structure,unstable welding and tube core rollover are also easy to occur in inverted packaging.To this end,we optimized its structure on the basis of traditional inverted packaging,and propose a new inverted packaging structure.The novel inverted encapsulated microdisk cavity semiconductor laser is prepared by preparing a pillar on the opposite side of the tube core,forming a dual support structure for the substrate in the inverted packaging,while reducing the temperature of the active region of the device,the packaging reliability is also guaranteed.2.We have prepared positive and inverted encapsulated microdisk cavity semiconductor laser single tubes respectively,and we introduced the thick glue mask workmanship and Si₃N₄insulation workmanship.The test results show that:The prepared Lima（?）on microdisk cavity semiconductor laser has obvious main lobe light output in the horizontal direction;Lasing wavelength 9.985μm;The peak output power of positive packaging devices is only 10.8m W,while that of devices with new inverted packaging is up to 12m W.3.In order to further improve the output power of microdisk cavity semiconductor laser,we introduced a new array inversion packaging structure.The pillar array structure is prepared on the basis of array inverted packaging,and added a transition heat sink to further alleviate the high thermal stress caused by its operation.We also discussed the packaging of different transition heat sinks and the superposition of thermal fields of each light-emitting unit.We designed the double solder packaging process of Au Sn and in,which effectively avoided the secondary melting of the first layer solder due to the increase of temperature in the process of secondary patch.Finally,we prepared a microdisk cavity semiconductor laser with Al N transition heat sink,650μm center spacing of light-emitting units and a new array inverted package,with an output power of 34.6 m W.