However, these green laser pointer are far from practical devices. In order to promote the birth of high-power semiconductor lasers, the integration of different technologies must be achieved. Key technological innovations began with an understanding of direct bandgap semiconductor materials and crystal growth technologies. Subsequent developments include the invention of dual heterojunction lasers and subsequent developments of quantum well lasers.
The key to further enhancing these core technologies lies in the improvement of efficiency and the development of cavity surface passivation, heat dissipation and packaging technology. The innovations of the past few decades have brought exciting improvements. In particular, the improvement in brightness is excellent. In 1985, the most advanced high-power semiconductor laser at that time could couple 105 milliwatts of power into a 105 micron core fiber.
State-of-the-art high-power semiconductor lasers can now produce more than 250 watts of 105-micron fiber with a single wavelength-a 10-fold increase every eight years. Moore conceived of “fixing more components to integrated circuits”-subsequently, the number of transistors per chip increased 10-fold every 7 years. Coincidentally, high-power semiconductor green laser pointers incorporate more photons into the fiber at a similar exponential rate.