The Study Of External Cavity Spectral Beam Combining Technology On Mid-infrared GaSb Based Semiconductor Lasers

Mid-infrared semiconductor lasers(MSLs)has the prospect of application in environmental detection,space communication and military defense and other fields due to it's small size,long lifetime and high efficiency.It is very difficult to further increase the output power due to the limitations of device structure and material properties.Laser beam combining technology is an important approach to enhance the power of mid-infrared semiconductor lasers.Compared to other laser beam combining technologies,High-power,high-brightness mid-infrared laser sources are most likely to be obtained by spectral beam combining technology.In this paper,we focus on spectral beam combining technology with GaSb based semiconductor lasers and major in researching the external cavity in spectral beam combining technology.The main works are as follows:1)To study the recent progresses of spectral beam combining technology in mid-infrared semiconductor lasers.The research on the beam combining technology of mid-infrared semiconductor lasers by their researches institutions were analyzed.An article was published in the Infrared and Laser Engineering2)A system which constituted by GaSb based semiconductor lasers's external cavity used output coupling is established to study how the reflectivity of output coupling mirror effects the laser cavity?output power?beam quality and spectra.When the reflectivity of output coupling mirror was 33.5%,We got Output beam with M_y~2=7.68?M_y~2=10.87?490pm Spectral width and 87%effectiveness.3)A small angle V-shaped cavity was first used in the outer cavity of the mid-infrared GaSb based semiconductor laser to improve the low output effective of the output coupling mirror.In this method we studied the effect of the position of the mirror in a small-angle V-cavity on the output power and beam quality of the output beam,the conclusion was obtained that the power of the output beam and the quality of the slow-axis beam can be changed by changing the position of the mirror.When the distance of mirror was 0.5mm,We got Output beam with M_y~2=7.75?M_y~2=12.95?and 72.5%effectiveness.4)The two methods mentioned above were used in GaSb based Semiconductor Laser after Space Beam Combination.Output beam were obtained separately with M_x~2=35?68.5%effectiveness and M_x~2=38.1?72.3% effectiveness.