Experimental investigation of the package of diode laser chip based on lateral heat flow suppression

To improve slow axis beam quality of diode laser (LD) and decrease slow axis divergence angle, a new package with lateral heat flow suppression was designed utilizing the difference in thermal conductivity between air and heat sink. The finite element analysis software was used to analyze the temperature distribution with lateral flow suppression package. It is shown that diode laser chip soldered on trough heat sink with width W=120 μm and length L=4000 μm can reduce slow axis divergence angle about 14%, from 12.25° to 10.49°, when working current was 15A. Correspondingly, beam parameter product (BPP) can reduce from 5.344 mm·mrad to 4.5763 mm·mrad and the brightness of slow axis increased about 5.5% than before. According to the result, the lateral flow suppression package can weaken higher order mode caused by thermal lens effect of diode laser so that decrease slow axis divergence angle effectively.