Study On The Fiber Laser With Combined Pump And The Fiber Combiner

As a new type of solid laser, fiber laser is characterized by the rare earth ions doped double cladding fiber as a gain media. Benefiting from the special configuration of fiber waveguide, the fiber laser has performed much better then the other solid lasers in the following fields: better cooling condition, excellent beam quality, high efficiency and flexibility. All of these advantages, which make the fiber laser one of the primary schemes of future solid lasers, are very attractive all around the world. Actually the fiber laser has been widely applied in the fields of manufacturing, military, communication and therapy successfully. At present the coherent combining is studied for the higher output without the descend of beam quality. So the fiber combiner as a passive component, which makes the coherent combining available, has great potential. The basic theory of fiber laser is studied here. The integrated system of fiber laser is built up. With the combined pump source the max 20W output is obtained. The technique of fiber combiner is explored too.The efficient air cooling is employed to control the wavelength of LDs around 915nm in the experiment of fiber laser with combined pump sources, which makes the width of wavelength 6nm when 6 LDs operating. Test the combiner and the water cooling is employed. The pump coupling is carried out with a two-lens system practically. The absorbing coefficient is test by cutting the active fiber, which helped us to decide the best length in the later experiment, 22m. The length is tally with the experiment result well. Meanwhile, the reabsorption is validating. The holistic experiment has the result as follows: in the 4×1 pump experiment, output of 10.5W, slope efficiency of 65% and 46% for holistic efficiency are obtained; in the 6×1 pump experiment 20.5W output and slope efficiency of 75% are obtained.The technique of tapered fused bundle combiner is explored. The method of removing the coating of fiber is mastered. The parameters of tapering are studied. And rough tapers are obtained.