Research On Optical Fiber Cladding Mode Strippers With Cemented Quartz Tube

Within the past decades, the performance levels of high-power delivery optical fibers have been enhanced significantly, due to the more diversified and sophisticated demands. As one of the most important components for this kind of optical fibers, a cladding mode stripper is commonly used to protect the coating structure from being burned by the unwanted cladding light and improve the output beam quality. So the related studies have recently gained great interest.In this paper, a cladding mode stripper with cemented quartz tube has been introduced, based on the summary of worldwide research findings. The cladding mode stripper is designed to be capable of removing cladding light gradually over a certain length. In order to compare with the performance of the cladding mode stripper with cemented quartz, ultraviolet curing adhesives of different refractive indices are recoated upon the claddings and the performances of them have been investigated. According to the simulation results, the adhesives of higher indices will not be able to make the stripping process uniform. Then the scattering property of air bubble in ultraviolet curing adhesives has been theoretically studied. An equation to calculate how light beam scattering is established and the scattering data are obtained when the refractive index of adhesives, bubble size and shape are changed. The results show that these bubbles are in favor of enhancing cladding light scattering. In addition, a model on the basis of Lambert's cosine law is built in this part. The characteristics of scattering is related to the surface etching, which is determined by the thickness of quartz tubes.Based on the points discussed above, several preparation techniques of the cladding mode stripper are investigated as well. Fiber coating stripping, ends cutting and the usage of adhesives are included in this part. Then two types of cladding mode strippers are made by using high refractive-index adhesives and quartz tubes, respectively. The high-peak power lasers have been employed to texture the inner surface of quartz tubes.In the end, the output property and light extraction performance of the prepared cladding mode strippers are studied experimentally. The results show that cladding mode strippers recoated with higher refractive-index adhesives are capable of extracting cladding light effectively. However, the non-uniformity of light stripping over the adhesive layer is harmful as the previous part discussed. Instead, a cladding mode strippers with cemented quartz tube have the ability to overcome this challenging problem.