The Study Of Spectral Beam Combining On Diode Laser By Grating And External Cavity

High power and high beam quality are important technical indicators for a direct diode laser light source applications, at the current state-of-art grating-external cavity spectral beam combining is the most effective way to achieve high brightness direct diode laser (DDL) outputs, The technology is scalable to tens of kW of output power while maintaining very high beam quality. The company TeraDiode, using the spectral beam combining patented technology of MIT Lincoln Laboratory, has combined large number of independent diode laser beam a bunch laser beam with output power and beam quality that are comparable to that of existing industrial lasers, such as CO2, fiber, and bulk solid-state lasers. Such a direct diode laser will be used infrared countermeasures, target designators, target illuminator and industrial processing, etc. On the long-term goals, will be applied to directed energy weapons such as roadside bombs distance Clear, anti-rockets, artillery and mortar shells tasks, as well as other aspects of the application of air defense. It can be seen:the spectral beam combining will be a revolutionary of beam combining technology, making the diode laser among the ranks of the direct application of the laser source.This paper mainly focused on the grating-external cavity spectral beam combining and started to do some research about high-brightness spectral beam combining diode laser light source, and the main accomplished work as follows:1) Introduced the development of an incoherent beam combining technology-external cavity feedback grating spectral beam combining which could improve the output optical power density and output beam quality of diode laser. Summarized a number of important trends in the development of diode laser spectral beam combining technology, provided a reference and guidance for future research of diode laser spectral beam combining technology. In relation to the work an academic research paper was accomplished at the same time, published in the Laser & Optoelectronics Progress vol.52,2015.2) According to the problems encountered during the experiment, the concept of spectrum inter-locking was proposed, and given a simple analysis and experimental verification about the cause of spectrum inter-locking, proposed several effective method to inhibition inter-locking between spectral beam combining units.3) To meet the needs of laser pump, a spectral beam combining optics was designed to realize narrow spectral output, gained wide spectrum width of the laser output 3.25nm, to our knowledge, this is the narrowest spectral ever achieved from a broad area diode laser bar. The result was published in the Chinese journal of laser vol.42,2015. On the basis of the above result, miniaturization structure of high-brightness and narrow spectral light source was proposed,1 authorized utility model patents was licensed.4) In order to obtain a higher power output and realize the same beam quality in both dimension by the spectral beam combining diode laser system, a diode stack that consisted of 3-Mini-Bar based on the transmission grating was designed and implemented, and for the first time proposed a plan-convex cylindrical lens as a feedback cavity mirror structure, to achieve a good improvement in the beam quality and suppression of spectrum inter-locking.5) For the sake of achieving the beam quality improvement of spectral beam combining, a splitting feedback spectral beam combining architecture was proposed, and 1 authorized utility model patents was licensed.