Panasonic Overcomes Blue-Violet Laser Heat Limitation

An advance in heat-dissipation technology has enabled development of a 4.5-W blue-violet semiconductor laser that could help make lighting and laser-machining systems smaller and more efficient.

Panasonic Corp. said its laser's output power is 1.5 times greater than similar lasers, even at the conventional maximum operating temperature of 60 °C. It also oscillates with energy conversion efficiency of 33 percent — 1.2 times higher than that of conventional lasers.

Comparison of conventional and double heat-flow packaging for blue-violet semiconductor lasers. Courtesy of Panasonic.

In general, the output power of semiconductor lasers decreases as the laser chip temperature rises. Conventional blue-violet lasers dissipate heat from only one side of the laser chip, causing the laser chip temperature to increase and limiting output to approximately 3 W. Systems requiring an output of tens of watts would require a large number of lasers, causing more heat to be generated and requiring larger heat sinks.

Panasonic developed double heat-flow packaging technology that can suppress this temperature increase. Consequently, the drop in laser light output caused by heat can also be prevented, enabling high-output and high-efficiency operation. As a result, in laser systems using multiple lasers, the number of lasers can be reduced to two-thirds of those using conventional lasers. Moreover, because the heat sinks can be smaller, the system itself can be made smaller and lighter.

The work was partially supported by the Japanese Strategic Innovation Program for Energy Conservation Technologies.