Study On The Mechanism Of Stress And High Temperature Characteristics Of High Power Quasi-continuous Semiconductor Laser Array

High-power semiconductor lasers are widely used in pumping solid-state lasers,industrial fine processing,medical cosmetology,intelligent sensing and other fields due to the advantages of high efficiency,high output power,long lifetime,small volume,and easy integration.With the expansion of the application field,the practical application need more harsh requirements on the reliability and high-temperature characteristics of high-power semiconductor lasers,which makes the improvement of their overall performance face greater challenges,and these studies has less reports at home and abroad,thus it is more urgent to deeply study the internal mechanism of high-power semiconductor laser devices affecting their performance output under actual working conditions,so as to provide important guidance for the development of high-power semiconductor laser chips and practical application of devices.The stress generated by high-power semiconductor laser packaging has huge impact on its reliability,which directly determines its performance,how to control the packaging stress is particularly important;at the same time,the overall output performance of high-power semiconductor lasers under high temperature conditions have huge changes,which are difficult to meet the needs of direct applications,and the internal energy loss mechanism is not yet clear.So high-power 960 nm quasi-continuous semiconductor lasers arrays packaged by microchannel cooler were study,it mainly study the stress distribution of the array and the output characteristics at high temperature,which provides important guiding significance for the development of high-power and high-reliability semiconductor laser arrays.The following research work has been carried out:(1)The overall performance of high-power quasi-continuous semiconductor laser array devices is highly dependent on the performance of all individual emitters on the chips.First,through stress theory analysis,the strain expression of the independent emitters in the packaged laser array is derived,and the relationship between strain and wavelength drift is established.Then,the laser photoelectric characteristics parameters such as threshold current,slope efficiency,spectrum and optical power were measured via our test setup,according to the wavelength of each emitter at a low duty cycle of 0.1%(100?s,10Hz),the corresponding strain value is obtained.From our study,it is clear that external stress can significantly affect the laser's parameter performance.Specifically,compressive strain will cause blue-shift in wavelength,decrease in threshold current,and increase in laser and slope efficiency;tensile strain by contrast,will have completely opposite effects on the laser performance.The distribution of stress can basically predict the pattern of array performance,which has important guiding significance for the development of high peak power,high reliability semiconductor laser arrays.(2)Through the precision temperature control system,a series of photoelectric characteristics of high-power quasi-continuous semiconductor laser array device such as the peak power,power conversion efficiency,working voltage and spectrum are tested from 10? to 80?.First,the changes of various performance parameters were analyzed,with the increase of temperature of the laser array,it will cause decrease in output power,decrease in the operating voltage,red-shift in the center wavelength,broadening in the spectral,and decrease in power conversion efficiency;secondly,combined with the theoretical analysis of the input energy loss distribution,the ratio distribution of the energy loss in the laser array at different temperatures is given.The results show the power conversion efficiency drops from 63.95% to 47.68% after the operating temperature is increased from 10°C to 80°C,and the proportion of carrier leakage losses increases from 1.93% to 14.85%,which is the main factor that causes the decline in the power conversion efficiency.This study has important guiding significance for the applications and chip design of high peak power semiconductor laser arrays at high temperature.