1. Method to improve near-field nonlinearity of a high-power diode laser array on a microchannel cooler
- Author
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Yangtao Jia, Xingsheng Liu, Tao Chunhua, Cai Wanshao, Hongyou Zhang, and Chung-En Zah
- Subjects
Microchannel ,Materials science ,business.industry ,Bar (music) ,General Engineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Collimated light ,law.invention ,Semiconductor laser theory ,010309 optics ,Optics ,law ,Mathematics::Category Theory ,0103 physical sciences ,Laser bonding ,0210 nano-technology ,business ,Diode ,Common emitter - Abstract
Due to thermal stress, each emitter in a semiconductor laser bar or array is vertically displaced along the p-n junction; the result is that each emitter is not in a line, called near-field nonlinearity. Near-field nonlinearity along a laser bar (also known as “SMILE” effect) degrades the laser beam brightness, which causes an adverse effect on optical coupling and beam shaping. A large SMILE value causes a large divergence angle after collimation and a wider line after collimation and focusing. We simulate the factors affecting the SMILE value of a high-power diode laser array on a microchannel cooler (MCC). According to the simulation results, we have fabricated a series of laser bars bonded on MCCs with lower SMILE value. After simulation and experiment analysis, we found the key factor to affect SMILE is the deformation of the thin MCC because of the distribution of strain and stress in it. We also decreased the SMILE value of 1-cm-wide full bar AuSn bonded on MCCs from 12 to 1 μm by balancing force on MCC to minimize the deformation.
- Published
- 2018