Research On High-efficiencyspectral Beam Combining Of Semiconductor Laser

With the progress of technology and the development of semiconductor laser applications,semiconductor lasers are moving toward higher output power and good beam quality.The paper summarized the methods of improving the output power and the beam quality and analyzed the advantages and disadvantages.Compared to coherent and non-coherent beam combining,the spectral beam combining(SBC)technology can greatly improve the output power while maintaining the beam quality.In order to make more efficient use of SBC technology,it is necessary to further optimize the optical components in the process of combining.Based on the SBC technology,we have conducted following work:(1)Introducing the SBC technology in detail and the concept of equivalent cavity and equivalent reflectivity,the combining efficiency was deduced theoretically.It was found that the combining efficiency was related to the internal-cavity parameters and external-cavity parameters.(2)Using the MATLAB software to simulate the combining efficiency,it was found that when the focal length of the lens was 100 mm,the combining efficiency increases first and then decreases rapidly with the increase of R.In the experiment,when the R was 5%,7.5%,10%,15%,20%,25% and 30% respectively,the beaming efficiency was 72%,74%,77%,73%,65% and 57%respectively.Experimental results verified the theoretical analysis.We can get that when f is 200 mm,R=10% is best.(3)Using the ZEMAX software to simulate the equivalent cavity of the SBC,it was found that the combining efficiency decreased with the increase of the focal length of the lens.This is because that when the f is larger,the loss of feedback caused by the aberration of the lens and divergence angle is greater.In the experiment,when R was 10% and f was 100 mm,130mm,150 mm and 200 mm respectively,the output power after combining was 54 W,51.9W,50.3W and 48.5W respectively,showing a decreasing trend;The same trend was obtained when R was 5%,7.5%,15% and 30% respectively.The simulation result was verified by the experimental results.