高功率氮化镓基蓝光激光器

High Power GaN-Based Blue Lasers

高功率氮化镓基蓝光激光器在激光显示、激光照明和材料加工等领域具有很大的应用前景。通过优化蓝光激光器p-AlGaN限制层的生长温度,抑制了量子阱热退化,通过优化量子阱结构,改善了载流子分布,研制出了高功率蓝光激光器。利用变腔面反射率法获得蓝光激光器的内部光学损耗为6.8 cm^-1,载流子注入效率为90%。在脉冲工作条件下,蓝光激光器的阈值电流密度为1 kA/cm^2,斜率效率为1.65 W/A,预计在6 kA/cm^2电流密度下,输出光功率能达到4 W;在连续工作条件下,激光器的阈值电流密度为1 kA/cm^2,由于封装散热性能不佳,斜率效率下降为1 W/A,预计在6 kA/cm^2的电流密度下,输出光功率为2.2 W。

High-power blue lasers based on gallium nitride(GaN)have significant prospects in numerous applications,such as laser display,laser lighting,and metal processing.In this study,the epitaxial growth temperature of the p-AlGaN cladding layer of blue lasers is optimized to suppress the thermal degradation of the quantum wells(QWs)and QW structures are optimized to improve the carrier distribution to achieve high-power blue lasers.Upon varying the front facet-coating reflectivity,the internal optical loss and carrier injection efficiency are deduced to be 6.8 cm-1 and 90%,respectively.Under pulsed operations,the threshold current density of the blue lasers is 1 kA/cm^2 and the efficiency gradient is 1.65 W/A.Thus,the expected output power is 4 W at a current density of 6 kA/cm^2.Under continuous-wave operations,the threshold current density of the blue lasers is 1 kA/cm^2 and the efficiency gradient drops to 1 W/A for poor packaging heat dissipation perform.Thus,the output power reaches 2.2 W at a current density of 6 kA/cm^2.