Method for improving coupling efficiency of high-power pulsed laser optical fiber

Abstract

The invention discloses a method for improving the coupling efficiency of a high-power pulsed laser optical fiber. The method includes the following steps of: first step, optical fiber selection; second step, optical fiber tapering; third step, optical fiber connection; and fourth step, lens coupling. According to the method of the invention, a large-core diameter optical fiber is adopted as a receptor of space laser, the laser receiving area of the large-core diameter optical fiber is larger, so that the laser energy density of the receiving surface can be effectively reduced, and therefore,higher laser energy can be coupled; after the laser passes through the large-core diameter optical fiber, the space energy distribution of the laser is homogenized, end surface loss can be effectivelyreduced after the laser is coupled into a small-core diameter optical fiber, and therefore, such kind of laser coupling mode can improve a coupling threshold value compared with a laser space directcoupling mode; and the large-core diameter optical fiber and the small-core diameter optical fiber can be connected with each other through an optical fiber connector, so that the alignment of the large-core diameter optical fiber and the small-core diameter optical fiber can be realized; and the small-core diameter optical fiber can be replaced as a consumable, so that the replacement of an entire optical path can be avoided when the small-core diameter optical fiber is damaged.

Description

technical field [0001] The invention relates to a method for improving laser transmission efficiency, in particular to a method for improving high-power pulse laser fiber coupling efficiency, and belongs to the field of laser technology. Background technique [0002] The technology related to the interaction between laser and matter is widely used in many industries such as micromachining, micromolding, and the ignition and detonation of energetic materials. On the surface of the material, it can obtain the effect of the transient state. At present, the relevant experimental optical paths of high-power lasers are usually arranged in free space, but this optical path layout brings problems such as high difficulty in sample alignment, great influence of the air environment, easy burns to the human body, and low space utilization. The above problems can be effectively avoided. However, for high-power lasers, if the optical fiber is used for direct coupling, more than GW / cm 2...

AI Technical Summary

Problems solved by technology

At present, the relevant experimental optical paths of high-power lasers are usually arranged in free space, but this optical path layout brings problems such as high difficulty in sample alignment, great influence of the air environment, easy burns to the human body, and low space utilization. can effectively avoid the above problems

However, for high-power lasers, if the optical fiber is used for direct coupling, more than GW / cm 2 The high laser power density makes the fiber material unbearable, especially at the incident surface of the fiber coupling, the fiber is often ablated and damaged, and the laser energy cannot be effectively transmitted

[0003] The reason why the optical fiber cannot effectively couple high-power lasers is not only the material, process, and surface finish of the optical fiber itself, but also the inhomogeneity of the laser energy transmitted in free space causes local excessively high energy density, which will also cause damage to the optical fiber.

And if the optical fiber with small core diameter is directly used for coupling, the focusing ability of the laser (that is, the size of the focused focal spot) and the alignment with the optical fiber will also bring great difficulties, making it difficult to directly use the optical fiber with small core diameter to directly Coupled high power pulsed laser

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