Applications: Laser Pumping

A new class of applications are being pursued with QPC semiconductor lasers because of their high brightness, high power performance.

Traditionally, diode lasers have been used in printing, defense, medical, and materials processing applications because of the device compactness, high power capability, and high electrical to optical efficiency. However, the applications have been limited due to the low brightness performance of typical diode lasers. QPC’s high brightness, high power semiconductor laser technology is enabling new applications in these markets, allowing the end user to achieve high brightness and enjoy all the benefits of traditional diode lasers.

The most common application of semiconductor lasers is pumping the gain medium of solid state and fiber laser systems. In diode pumped laser architectures, the semiconductor laser light “pumps” or excites the gain medium which is configured inside its own laser cavity. The pump light is absorbed by the crystal or fiber, and a solid state or fiber laser is created.

Diode pumping has significant advantages over traditional approaches that utilize lamps as pumps. In fact, nearly every important parameter of a laser system is improved with diode pumped architectures including system size, weight, performance and cost of ownership.

The most dramatic advantage to diode pumping is the improved efficiency of the laser system. Lamps are inefficient, and most of the light that the lamps produce is not absorbed by the gain medium and is converted into heat that then has to be removed from the system. Diode lasers are highly efficient, and they emit light over a narrow portion of the spectrum which can be designed to closely match the absorption window of the gain medium.

Since laser beam quality degrades with thermal distortions in the gain medium, the high efficiency diode pumped approach reduces the heat absorbed by the gain medium and improves the final beam quality of diode pumped laser. Moreover, the high efficiency of the laser reduces system complexity, operating cost, and size by reducing the amount of waste heat in the system.

Operating cost is further reduced since diode laser reliability is far better than lamps which need changing on a weekly or monthly basis.