阅读说明：本技术 一种光纤合束分束器 (Optical fiber beam combining and splitting device ) 是由 刘玙 吴文杰 宋华青 黄珊 陶汝茂 沈本剑 李敏 冯曦 于 2021-04-01 设计创作，主要内容包括：本发明涉及一种光纤合束分束器,属于激光器技术领域,所述光纤合束分束器采用型结构,其在应用效果上是将根输入光纤中的激光合成后分配到根输出光纤中,等效于使用个型结构光纤合束器,其中,为输入光纤数量,为输出光纤数量,其光学结构为一体化结构,充分利用了根输入光纤组成的光纤束横截面上外圈相比内圈能容纳更多光纤数量的特点,使相比于型结构光纤合束器,光纤的等效拉锥比得以降低,本发明既有助于减少激光器中光学器件的数量,简化激光器的布局、排线和集成,又有助于激光器小型化和轻量化,同时,采用型结构,能够降低光纤的拉锥比例,有效提升合成效率,减少热负载,抑制温升速率。(The invention relates to an optical fiber beam combiner and splitter, which belongs to the technical field of lasers and adopts A structure of a mold which will be effective in application Laser light in root input fiber is synthesized and distributed to Root output fiber, equivalent to use An The optical fiber beam combiner with the structure of the model is provided with a beam splitter, in order to input the number of optical fibers, for outputting the quantity of optical fibers, the optical structure is an integrated structure, and the full use of The outer ring of the cross section of the optical fiber bundle consisting of the input optical fibers can contain more optical fibers than the inner ring, so that the optical fiber bundle can contain more optical fibers than the inner ring The optical fiber beam combiner with the structure has the advantages that the equivalent tapering ratio of the optical fibers is reduced, the number of optical devices in the laser is reduced, the layout, the wiring and the integration of the laser are simplified, the miniaturization and the light weight of the laser are facilitated, and meanwhile, the optical fiber beam combiner with the structure adopts The tapered structure can reduce the tapering proportion of the optical fiber, effectively improve the synthesis efficiency, reduce the heat load and inhibit the temperature rise rate.)

1. An optical fiber beam-combining splitter is characterized in thatA shape structure equivalent toAnAn optical fiber combiner of a type structure is provided withA root input optical fiber,The output optical fiber is arranged at the root end of the optical fiber,the number of optical fibers contained in the outer circle of the cross section of the optical fiber bundle consisting of the input optical fibers is more than that of the optical fibers contained in the inner circle, wherein,the optical fiber combiner is provided withRoot input optical fiber, 1 output optical fiber.

2. An optical fiber beam combiner according to claim 1, wherein the input optical fiber is a multimode optical fiber, a single mode optical fiber or a few mode optical fiber.

3. An optical fiber beam combiner according to claim 2, wherein said input optical fiber is connected to a laser diode or a fiber laser.

4. A beam splitter as claimed in claim 2 or 3, wherein the number of output fibres is such thatWith equivalentThe number of the optical fiber beam combiners with the structure is equal.

Technical Field

The invention belongs to the technical field of lasers, and particularly relates to an optical fiber beam combining and splitting device.

Background

Fiber lasers commonly employ laser diodes as pump sources. In order to increase the laser power, a pump beam combiner is generally used to combine and inject pump light emitted from a plurality of laser diodes into a gain fiber of a fiber laser. Such a pump beam combiner for a fully-fibrillated laserNamely a fiber-pumped beam combiner (US 2018/0102623 a 1), whichThe structure of the optical fiber amplifier is characterized in that the optical fiber amplifier has N pumping optical fiber inputs and 1 optical fiber output, and can directly superpose pumping light in at most N pumping sources into the same optical fiber, as shown in figure 1. The optical fiber combiner is an optical fiber device prepared on the basis of a fused biconical taper optical fiber bundle, a bundle of optical fibers are stripped of a coating layer and then arranged together in a certain mode, the optical fibers are heated at high temperature to be fused, meanwhile, the optical fiber bundle is stretched, and an optical fiber heating area is fused to form the fused biconical taper optical fiber bundle, for example, the application number is CN201811150456.0, namely, the optical fiber combiner preparation method and the optical fiber combiner.

For the fiber laser with MOPA configuration and the fiber laser with reverse pump or bidirectional pump, the pumping beam combiner is required to be capable of superposing pumping sources and directly transmitting signal laser, and the pumping beam combiner is adopted in the situationThe structure of the mould is as follows,the cross section distribution of N pumping fibers surrounding 1 signal fiber is shown, N pumping light and 1 signal light are integrated into the same optical fiber, and the optical fiber is also generally calledA pump signal buncher as shown in fig. 2. At present, due toThe pumping signal buncher has complex process and most of the structuresAndit is difficult to obtain the value of N of 18 or more. Therefore, to further increase the pump light power, fiber laserThe optical device usually adopts a cascade structure of pump beam combiner and beam buncher, as shown in FIG. 3, by cascading N₂AnThe pumping beam combiner can be superposedA laser diode.

Disclosure of Invention

The inventor repeatedly researches the existing pump beam combiner-beam combiner cascade structure and finds that the pump beam combiner-beam combiner cascade structure has two problems: one is that the number of devices used is large, requiring a total ofThe beam combining/bundling device not only increases the complexity of the layout, the wiring and the integration of the fiber laser, but also goes against the development trend of miniaturization and light weight of the fiber laser. Second, the pumping optical fiber has a larger taper ratio, so that the brightness of the pumping light is conserved (Wherein, in the step (A),for the numerical aperture of the input laser light,TR is the tapering ratio of the combining/bundling device, which is the numerical aperture of the output fiber) approaches the critical or difficult to maintain, the pump light loss is high, and the output fiber of the combining/bundling device heats seriously.

In particular, as commonly used in present day lasers for research and industryPump combiner cascadeThe structure of the pump signal buncher is as follows:the diameter of the input optical fiber of the beam combiner is 125 μm, the clear aperture of the output optical fiber is 220 μm, the numerical aperture is 0.22, and the tapering ratio of the beam combiner is. If the laser is connected with the conventional universal hectowatt power laser diode (the numerical aperture of the laser is generally 0.15), the numerical aperture of the laser is changed into the numerical aperture of the laser after passing through the cone of the beam combinerExceeds the limit of the numerical aperture of the output optical fiber of the beam combiner, so that the synthesis loss reaches several percent even ten percent,the pump beam combiner has extremely high thermal load, the output optical fiber generates heat seriously, and even the later-stage cascade connection is influencedThe resultant efficiency of the buncher aggravates the thermal load of the succeeding buncher.

In order to solve the above problems, a fiber combiner/splitter is proposed to greatly reduce the tapering ratio of the optical fiber and the loss.

In order to achieve the purpose, the invention provides the following technical scheme:

an optical fiber beam combiner comprisesThe structure is applied to the effect that the laser in P input optical fibers is synthesized and distributed into M output optical fibers, P represents the number of the input optical fibers, M represents the number of the output optical fibers, and the structure is equivalent to M output optical fibersAn optical fiber combiner of a type structure is provided withA root input optical fiber, M output optical fibers,representing the number of input fibres, M representing the number of output fibres, P₁To representThe optical fiber combiner with the structure of the type is used for inputting the number of optical fibers, wherein,by usingThe outer ring of the cross section of the optical fiber bundle composed of the input optical fibers can contain more optical fibers than the inner ring, compared with the optical fiber bundle composed of the input optical fibersThe optical fiber beam combiner with the structure has the advantages that the equivalent tapering ratio of the optical fiber is reduced, and the combining efficiency is improved.

Due to the fact thatThe application effect of the structure is that the laser in P input optical fibers is combined (equivalent to beam combination) and then distributed (equivalent to beam splitting) to M output optical fibers, namelyThe type structure has the beam combination and beam splitting effects, so the theme name is named as the optical fiber beam combination splitter, and the optical fiber beam combination splitter belongs to a brand new structure.

Further, the input optical fiber is a multimode optical fiber, a single mode optical fiber or a few-mode optical fiber.

Further, the input optical fiber is connected with a laser diode or a fiber laser.

Further, the number M of the output optical fibers is equivalent toThe number of the optical fiber beam combiners with the structure is equal.

Further, P₁The number of the input optical fibers and the number of the output optical fibers of the optical fiber beam combiner/splitter are not necessarily integer.

Further, a post-stage cascade fiber combiner or a fiber buncher of the fiber combining and splitting device, or the fiber combining and splitting device can be directly applied, and laser power is redistributed after beam combining and splitting.

Further, the post-cascaded optical fiber combiner adoptsIn the form of structure, P₂Indicating the number of input fibers of a downstream cascaded fiber combiner usingIn the form of structure, P₂Indicates the number of input pump fibers of the optical fiber buncher in the subsequent cascade, and。

further, when the number of the optical fiber beam combiner and splitter is 1, the number of the input optical fibers of the post-stage cascaded optical fiber beam combiner is equal to the number of the output optical fibers of the optical fiber beam combiner and splitter, that is, the number of the input optical fibers of the post-stage cascaded optical fiber beam combiner and splitter is equal to the number of the output optical fibers of the post-stage cascaded optical fiber beam combinerThe number of the input pump fibers of the post-stage cascaded optical fiber buncher is equal to the number of the output optical fibers of the optical fiber beam combining splitter, namely。

Further, when the number of the optical fiber beam-combining beam splitters is P₃When is not in use, andthe number of input optical fibers of the post-cascaded optical fiber combiner and P₃The total number of output fibers of the individual fiber beam combiners is equal, i.e.The number of the input pump fibers of the post-stage cascaded optical fiber buncher is equal to the total number of the output optical fibers of the optical fiber beam combining and splitting device, namely。

The invention has the beneficial effects that:

not only is beneficial to reducing the number of optical devices in the laser and simplifying the layout, wiring and integration of the laser, but also is beneficial to the miniaturization and light weight of the laser, and simultaneously, the adoption of the methodThe tapered structure can reduce the tapering proportion of the optical fiber, effectively improve the synthesis efficiency, reduce the heat load and inhibit the temperature rise rate.

Drawings

FIG. 1 isThe structure schematic diagram of the optical fiber pumping beam combiner;

FIG. 2 isThe structure schematic diagram of the pumping signal buncher;

FIG. 3 is a schematic diagram of a pump combiner-buncher cascade;

FIG. 4 is a schematic view of the overall structure of the present invention;

FIG. 5 is a schematic diagram of a fiber combiner splitter cascade fiber bunchers.

In the drawings: 1-input fiber, 2-output fiber.

Detailed Description

In order to make the technical solutions of the present invention better understood, the following description of the technical solutions of the present invention with reference to the accompanying drawings of the present invention is made clearly and completely, and other similar embodiments obtained by a person of ordinary skill in the art without any creative effort based on the embodiments in the present application shall fall within the protection scope of the present application. In addition, directional terms such as "upper", "lower", "left", "right", etc. in the following embodiments are directions with reference to the drawings only, and thus, the directional terms are used for illustrating the present invention and not for limiting the present invention.

The first embodiment is as follows:

as shown in FIG. 4, an optical fiber beam combiner/splitter employsThe structure is applied to the effect that the laser in the P input optical fibers 1 is synthesized and distributed to the M output optical fibers 2, and is equivalent to the integration and combination of a plurality of optical fiber beam combiners, so as to reduce the number of optical devices.

Specifically, the optical fiber beam combiner/splitter is regarded as integrating M optical structuresAn optical fiber combiner of a type structure is provided withRoot input optical fiber 1, M output optical fibers 2, by usingThe outer ring of the cross section of the optical fiber bundle composed of the input optical fibers can contain more optical fibers than the inner ring, compared with the original optical fiber bundleThe optical fiber beam combiner can greatly reduce the equivalent tapering ratio of the optical fiber, improve the combining efficiency and reduce the loss of an optical device, wherein,said optical fiber is closedThe beam device is provided with P₁Root input optical fiber, 1 output optical fiber.

In addition, the optical fiber beam combining and splitting device has the functions of beam combining and beam splitting. The input optical fiber 1 is a multimode optical fiber, a single mode optical fiber or a few-mode optical fiber, that is, the optical fiber beam combiner can be a beam combiner for pumping light or a beam combiner for signal light. Correspondingly, the input optical fiber 1 may be connected to a laser diode or a fiber laser. In addition, the rear stage of the optical fiber beam combining and splitting device can be cascaded with the optical fiber beam combining device or the optical fiber buncher, the optical fiber beam combining and splitting device can also be directly applied, and laser power is redistributed after beam combining and splitting.

When the post-stage cascade optical fiber beam combiner or the optical fiber buncher of the optical fiber beam combiner/splitter adoptsIn the form of structure, P₂Indicating the number of input fibers of a downstream cascaded fiber combiner usingIn the form of structure, P₂Indicates the number of input pump fibers of the optical fiber buncher in the subsequent cascade, and。

specifically, when the number of the optical fiber beam combiner and splitter is 1, the number of the input optical fibers of the post-stage cascaded optical fiber beam combiner is equal to the number of the output optical fibers of the optical fiber beam combiner and splitter, that is, the number of the input optical fibers of the post-stage cascaded optical fiber beam combiner and splitter is equal to the number of the output optical fibers of the post-stage cascaded optical fiber beam combinerThe number of the input pump fibers of the post-stage cascaded optical fiber buncher is equal to the number of the output optical fibers of the optical fiber beam combining splitter, namely. When the number of the optical fiber beam-combining beam splitters is P₃When is not in use, andthe number of input optical fibers of the post-cascaded optical fiber combiner and P₃The total number of output fibers of the individual fiber beam combiners is equal, i.e.The number of the input pump fibers of the post-stage cascaded optical fiber buncher is equal to the total number of the output optical fibers of the optical fiber beam combining and splitting device, namely。

Example two:

as shown in fig. 5, the same parts of this embodiment as those of the first embodiment are not repeated, except that:

the number of the optical fiber beam combining and splitting devices is 2, the optical fiber beam combining and splitting devices are cascaded at the later stage, and the optical fiber beam combining devices cascaded at the later stage adoptConfiguration, number of input pump fibers of fiber bundler. The optical fiber beam combining and splitting device integrates M optical fiber beam combining and splitting devices on an optical structureAn optical fiber combiner of a type structure is provided withA number of input fibers, M output fibers, i.e. the number of output fibers andthe number of the optical fiber beam combiners with the structure is equal. At the same time, P₁Without specific requirement, it may be an integer or a non-integer, i.e. of said optical fibre beam combiner-splittersThe ratio of the number of input fibers to the number of output fibers is not necessarily an integer.

Example three:

commonly used with present lasers for research and industryPump combiner cascadeThe structure of the pump signal buncher is shown as an example (as shown in FIG. 3), and the optical fiber beam combiner/splitter is regarded as combining 3 optical fibersOptical fiber combiner (equivalent to pump combiner) formationAnd if the optical fiber beam combiner is used as the beam splitter (shown in fig. 4), the structure shown in fig. 3 is changed into the structure shown in fig. 5, and the total number of optical devices is reduced by 4. Meanwhile, compared with fig. 1 and 2, fig. 4 only arranges a circle of input fibers in multiple rows on the cross section of the input fiber 1, that is, the cross section area of the input fiber 1 is slightly larger than that of the prior art, but fig. 4 obviously reduces the total number of optical devices, and at the same time, can also effectively reduce the synthesis loss and the light-induced thermal energy.

Setting upThe beam combiner/splitter likewise uses an input fiber with a diameter of 125 μm, and a core/cladding diameterThe numerical aperture of the output optical fiber is 0.22, the tapering ratio of the beam combining and splitting device is. If the laser is connected with the conventional hectowatt power laser diode (the numerical aperture of the laser is generally 0.15), the numerical aperture of the laser is changed into the numerical aperture of the laser after passing through the beam combining and splitting deviceThe numerical aperture of the optical fiber is smaller than that of the output optical fiber, and the synthetic efficiency can be close to 100%. Under the condition, the thermal load of the beam combining and splitting device is very low, and the temperature rise rate of the output optical fiber and even the later-stage cascade optical fiber buncher can be effectively inhibited.

The present invention has been described in detail, and it should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.