Detailed explanation of high-power semiconductor laser fiber coupling technology

In recent years, high-power fiber lasers have received increasing attention and favor due to their excellent performance. They have been widely used in industrial processing, space optical communications, medical and military and other aspects. Its rapid development is largely due to With the advancement of high-power and high-brightness semiconductor laser technology, high-power semiconductor laser fiber coupling technology has always been a key core technology of high-power fiber laser technology. Conversely, the development of high-power fiber lasers (DPFL) pumped by semiconductor lasers has also led to the advancement of high-power semiconductor laser technology, especially high-power semiconductor laser fiber coupling technology. Since the output power of a single-tube semiconductor laser (LD) is limited to several watts, it is far from meeting the requirements of a high-power fiber laser pump source. To obtain greater output power, a laser diode array with multiple light-emitting units must be used ( LD Array). According to the different structure, the laser diode array is divided into line array (LD Bar) and area array (LD Stack), as shown in Figure 1 (a) and (b) respectively. The output power of LD Bar is generally tens of watts. To the order of hundreds of watts, the output power of LD Stack is generally hundreds of watts or even thousands of watts. Whether it is a single-tube LD or LD Array, its inherent structural characteristics determine that the semiconductor laser has problems such as large beam divergence, asymmetric output beam spot, and low brightness, which bring practical applications as a high-power fiber laser pump source. Great difficulty and inconvenience. A better solution is to couple the semiconductor laser into the optical fiber output, so that the flexible transmission of the optical fiber can be used to increase the flexibility of use, and the output beam quality of the semiconductor laser can be fundamentally improved.　　 High-power semiconductor laser array fiber coupling technology, as a high-tech, has a high technical content, involving key unit technologies such as semiconductor materials, fiber optics technology, micro-optics technology, micro-fine processing technology and coupling packaging technology. So far, high-power semiconductor laser array fiber coupling technology has mainly adopted two technical routes: fiber bundle coupling method and micro-optical system coupling method. The following will mainly take the LD Bar fiber coupling technology as an example to elaborate on the two methods. (The above is edited and compiled by fiber laser cutting machine from the Internet, please explain the source again for reprinting!)