WO2016066004A1 - 大功率弱拉锥低损耗泵浦/信号合束器 - Google Patents

大功率弱拉锥低损耗泵浦/信号合束器 Download PDF

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WO2016066004A1
WO2016066004A1 PCT/CN2015/091194 CN2015091194W WO2016066004A1 WO 2016066004 A1 WO2016066004 A1 WO 2016066004A1 CN 2015091194 W CN2015091194 W CN 2015091194W WO 2016066004 A1 WO2016066004 A1 WO 2016066004A1
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fiber
pump
core
loss
taper
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PCT/CN2015/091194
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English (en)
French (fr)
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孔令超
冷进勇
郭少锋
陈子伦
周朴
司磊
许晓军
陈金宝
刘泽金
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国防科学技术大学
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/255—Splicing of light guides, e.g. by fusion or bonding
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers

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  • the invention belongs to the field of fiber lasers, and relates to a pump/signal combiner, in particular to a high power weak taper low loss pump suitable for a fiber laser power amplification including a few high-order modes with low signal light loss/ Signal combiner.
  • the main oscillation power amplification (MOPA) structure is a common structure for realizing high power output of fiber lasers.
  • This structure usually consists of an oscillator and a primary amplifier or more amplifiers.
  • a fiber-optic pump/signal combiner (TFB combiner) based on fusion taper technology can efficiently couple signal light and pump light into the double-clad fiber of the fiber amplifier, so TFB combines
  • TFB combiner fiber-optic pump/signal combiner
  • the thermal effect caused by the loss of light inside the combiner becomes more and more significant, causing a temperature rise inside the combiner.
  • the combiner will fail structurally. Therefore, reducing the internal loss of the combiner, reducing the temperature rise, and increasing the ultimate power that the combiner can withstand has become one of the keys to further increase the power of the fiber laser.
  • the internal temperature rise of the combiner mainly comes from the absorption of the loss light, which includes: pump light loss light and signal light loss light. Usually, the latter is an important cause of the temperature rise of the combiner, and the signal light loss light is mainly generated at the taper zone and the fusion splice point.
  • US Pat. No. 7,737,070 B2 discloses a strong taper structure pump/signal combiner, an input signal fiber and an output fiber of the pump/signal combiner. Both are double-clad fibers with a core of 20 ⁇ m, an inner cladding of 400 ⁇ m, and a numerical aperture of 0.06/0.46 (hereinafter referred to as 20/400 fibers).
  • the pump fiber has a core of 200 ⁇ m and a cladding of 220 ⁇ m.
  • the beam combiner needs to chemically etch the cladding of the input signal fiber to change the outer diameter of the inner cladding to about 200 micrometers to form a bundle of fibers with the pump fiber to ensure the fiber bundle and the output fiber.
  • a strong taper (leaf ratio of 1.65) is required for the fiber bundle.
  • the core of the 20/400 fiber used in this patent document supports the two modes of LP 01 and LP 11. Since the taper ratio is 1.65, the buncher has a large loss (2 dB) for the LP 11 mode.
  • the strong taper structure combiner has shortcomings in the application of main oscillation power amplification (MOPA) structure fiber laser: (1) LP 01 mode loss is large, which is not ideal when high power signal light input.
  • MOPA main oscillation power amplification
  • the aforementioned U.S. patent is designed to reduce the LP 01 mode loss by changing the mode field diameter (MFD) of the input signal fiber core to the MFD of the output fiber core by a taper to achieve LP 01 mode optics.
  • MFD mode field diameter
  • Matching and low loss however, even in the case of mode field diameter matching conditions, the loss of LP 01 mode at the splice point is still 0.25 to 0.3 dB, which is not ideal for high power signal light input;
  • high order mode The loss is large or unable to couple into the core of the output fiber, which can cause damage to the combiner and a drop in laser efficiency, further limiting the increase in final output laser power. It is pointed out in the aforementioned U.S.
  • the increase in LP 01 mode loss at the melting point not only causes more waste heat, but also causes pattern degradation in the output fiber, i.e., generation of higher order modes. This results in these higher-order modes interfering with the LP 01 mode in the gain fiber of the subsequent fiber oscillator or fiber amplifier, causing gain instability. Unstable gain results in the generation of pulsed lasers whose peak power exceeds the destruction threshold of the fiber core material, ultimately leading to core damage. Therefore, the core concept of the aforementioned US patent is to reduce the loss of the LP 01 mode while ensuring that the high-order mode does not enter the core of the output fiber, that is, the high-order mode has a large loss inside the combiner. In fact, the beam combiner disclosed in the aforementioned U.S.
  • the high-order mode has entered the inner cladding of the input signal fiber in the taper region, and the mode field mismatch at the fusion joint is severe and the loss is large.
  • the aforementioned U.S. patent teaches that suppressing the high-order mode from entering the output fiber can avoid the generation of pulsed laser light to protect the fiber laser, the high-order mode generates a large amount of loss light inside the combiner due to large loss, which causes the inside of the combiner. More waste heat is generated, which seriously affects the safe operation of the combiner and even damages the combiner, and the damage threshold of the combiner due to loss of light is lower than the core material damage threshold generated by the pulsed light.
  • a fiber laser built with a large mode field fiber with a core supporting a small number of modes in the case of a high output optical power, most of the output light will contain a few high-order modes, if the combination described in the aforementioned U.S. patent is used.
  • the beam splitter further amplifies the fiber laser containing a small number of high-order modes, which will cause all losses in the high-order mode and cause the final output efficiency of the laser to drop.
  • the technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, to provide a high power weak taper low loss pump/signal combination for reducing signal light loss and for fiber laser power amplification including a few high order modes. Beamer.
  • the present invention adopts the following technical solutions:
  • a high power weak taper low loss pump/signal combiner comprising an output fiber, an input signal fiber and at least one pump fiber, one end of the input signal fiber
  • One end of the pump fiber is combined into a bundle of optical fibers with a tapered cone by a fusion taper, and the ratio of the taper is from 1 to 1.45, and the bundle of the optical fiber and the output fiber are welded through the end face.
  • the output fiber and the input signal fiber are double-clad fibers, and the pump fiber is a single-clad fiber.
  • the outer diameter of the end of the taper zone on the fiber bundle (with the output fiber fusion) is not larger than the inner cladding of the output fiber. Outer diameter.
  • the inner diameter of the inner cladding of the output fiber is from 500 micrometers to 800 micrometers.
  • the core diameter of the output fiber is not Less than the core diameter of the input signal fiber.
  • the output fiber has a core diameter of 25 micrometers to 40 micrometers
  • the input signal fiber has a core diameter of 20 micrometers to 30 micrometers. Micron.
  • the core diameter of both is selected on the premise that the core diameter of the output fiber is not less than the core diameter of the input signal fiber.
  • the core optical aperture of the output fiber is not less than the core numerical aperture of the input signal fiber.
  • the output optical fiber has a core numerical aperture of 0.06 to 0.08
  • the input signal fiber has a core numerical aperture of 0.06 to 0.07.
  • the numerical aperture of the two cores is selected based on the premise that the core numerical aperture of the output fiber is not less than the core numerical aperture of the input signal fiber.
  • the pump fiber is six.
  • the taper ratio refers to the ratio of the circumscribed circle diameter of the fiber bundle at the starting point of the taper zone to the outer diameter of the bundle of the fiber bundle at the end of the taper zone (where the output fiber is welded), that is, the taper zone The ratio of the first to the outer diameter.
  • a few high-order modes generally refer to one or more high-order modes supported in the core of the input signal fiber, depending on the diameter and numerical aperture of the input signal fiber core and the beam quality of the input signal laser.
  • the pump/signal combiner of the present invention reduces the taper ratio to between 1 and 1.45, achieving a weaker taper or no taper, ensuring low loss of pump light and greatly reducing the height.
  • the loss of the mode mode signal light further reduces the loss of the LP 01 mode signal light. Since the taper region loss and the splice point loss of the LP 01 mode and the high-order mode are both low in the case of a weak taper or no taper, the pump/signal combiner of the present invention can be used to include a few high order The power amplification of the mode fiber laser.
  • the core diameter of the output fiber in the pump/signal combiner of the present invention is not less than the core diameter of the input signal fiber, so as to ensure that the core/cladding area ratio of the output fiber is not reduced, so as not to lower the subsequent fiber amplifier.
  • the core/clad area ratio of the double-clad fiber has an important effect on the absorption of the pump light. In general, the core/clad area ratio is proportional to the absorption coefficient of the pump light. If the core/cladding area is relatively small, a longer gain fiber is required to maintain sufficient absorption of the pump light while maintaining the doping concentration constant, which may result in nonlinear effects in the fiber amplifier. , limit the increase in output power.
  • the core numerical aperture of the output fiber of the pump/signal combiner of the present invention is not less than the core numerical aperture of the input signal fiber, which can further reduce the mode field mismatch loss at the fusion splice point. Because increasing the numerical aperture of the output fiber core introduces high-order modes into the output fiber core, high-order mode participation mode coupling can reduce splice point losses.
  • FIG. 1 is a structural diagram of a pump/signal combiner (ie, 25/250-30/600 weak taper combiner) according to an embodiment of the present invention; intention.
  • FIG. 2 is a cross-sectional view, taken along line A-A of FIG. 1, showing a cross-sectional view of a bundle of optical fibers, in accordance with an embodiment of the present invention.
  • Fig. 3 is a graph showing the relationship between the taper region loss and the taper ratio of the LP 11 mode of the pump/signal combiner in the second embodiment of the present invention.
  • FIG. 4 is a diagram showing the relationship between the splice point loss of the pump/signal combiner and the numerical aperture of the output fiber core in Embodiment 3 of the present invention.
  • the pump/signal combiner comprises one output fiber 3 and one input signal fiber 2 And 6 pump fibers 1, one end of the input signal fiber 2 (the end only retains the core and the inner cladding) and one end of the pump fiber 1 is combined by a fusion taper into a bundle of fibers with a tapered cone 4, pulling The taper ratio is 1.21.
  • the fiber bundle is cut and then welded to the output fiber 3 through the end face at the fusion splice point 5.
  • the output fiber 3 is a double-clad fiber having a core diameter of 30 ⁇ m, an inner cladding outer diameter of 600 ⁇ m, and a core/inner cladding numerical aperture of 0.07/0.46.
  • the input signal fiber 2 is a double-clad fiber
  • the core diameter of the input signal fiber 2 is 25 ⁇ m
  • the outer diameter of the inner cladding is 250 ⁇ m
  • the numerical aperture of the core/inner cladding is 0.06/0.46.
  • the pump fiber 1 is a single-clad fiber having a core diameter of 200 ⁇ m, a cladding diameter of 220 ⁇ m, and a core numerical aperture of 0.22.
  • the length of the tapered portion 4 is 1 cm.
  • the pump/signal combiner with different taper ratios of the input signal fiber 2 with core diameters of 20 ⁇ m and 25 ⁇ m, pump/signal is prepared in this embodiment.
  • the other structural parameters of the combiner are the same as those of the embodiment 1.
  • the pump/signal combiner of the present embodiment has a relationship between the loss of the LP 11 mode signal light in the taper region 4 and the taper ratio when the length of the taper region 4 is 1 cm, wherein the input signal
  • the core diameter of the optical fiber 2 is 20 ⁇ m and 25 ⁇ m, respectively, and the core numerical apertures of both fibers are 0.06.
  • Both input signal fibers 2 can achieve better mode control by conventional reasonable fiber coiling, that is, only two modes are output: LP 01 mode and LP 11 mode, so the combiner of this embodiment is based on lowering LP 01 and LP 11 is designed for the loss of two modes. Since the LP 01 mode can basically pass through the tapered cone 4 without loss, the loss of the LP 11 mode is very sensitive to the response of the taper ratio, so only the LP 11 mode and the taper ratio are given in Fig. 3 in two different cores. The relationship between the diameter of the input signal fiber 2. It can be seen from Fig.
  • the taper region loss of the LP 11 mode is less than 0.2 dB, especially for the case where the core is 25 ⁇ m, the LP 11 mode is substantially absent in the taper region 4. loss.
  • the patented utility model (US7373070B2) discloses a strong taper structure pump/signal combiner having a corresponding taper ratio of 1.65 and a LP 11 mode loss of 2 dB, which is much larger than the LP 11 mode pull of the embodiment. Cone area loss.
  • a pump/signal combiner with different output fiber core numerical apertures is prepared, except for the output fiber core numerical aperture, pump/
  • the other structural parameters of the signal combiner are the same as those of the embodiment 1.
  • the input signal light mode is only LP 01 mode and LP 11 mode, as shown in FIG. 4, the loss when the LP 01 mode and the LP 11 mode pass through the fusion splice point 5 is given, when the output optical fiber 3 has a core numerical aperture of 0.06.
  • the LP 01 , LP 02 , and LP 11 modes participate in the coupling.
  • the loss of the LP 01 mode is sufficiently low (0.02 dB), and the splice point loss of the LP 11 mode is 0.46 dB.
  • the numerical aperture is gradually increased, the welding point loss of the two modes is gradually reduced.
  • the numerical aperture is greater than 0.062, the core of the output fiber 3 will support the LP 12 mode, and the loss of the welding point of the LP 11 mode rapidly decreases.
  • the numerical aperture is increased to 0.07, the splice point loss in the LP 11 mode is reduced to 0.13 dB. If the core numerical aperture of the output fiber 3 is too large, a higher order mode will be introduced into the output fiber core. Although the loss at the fusion spot 5 will be further reduced, the beam quality of the output laser will deteriorate rapidly. Therefore, in order to maintain the beam quality of the output light, the core numerical aperture of the output fiber 3 cannot be excessively large.

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Abstract

一种大功率弱拉锥低损耗泵浦/信号合束器，该泵浦/信号合束器包括输出光纤(3)、输入信号光纤(2)和至少一根泵浦光纤(1)，输入信号光纤(2)的一端与泵浦光纤(1)的一端通过熔融拉锥结合为一带有拉锥区(4)的光纤组束，拉锥比例为1～1.45，光纤组束与输出光纤(3)通过端面熔接。大功率弱拉锥低损耗泵浦/信号合束器可降低信号光的损耗，用于包含少数高阶模式的光纤激光功率放大。

Description

大功率弱拉锥低损耗泵浦/信号合束器 【技术领域】
本发明属于光纤激光器领域，涉及一种泵浦/信号合束器，尤其涉及一种信号光损耗低、适用于包含少数高阶模式的光纤激光功率放大的大功率弱拉锥低损耗泵浦/信号合束器。
【背景技术】
与一般的激光器相比，光纤激光器在光束质量、体积、重量、效率、散热等方面均有明显优势，已经成为激光器领域最热门的研究方向之一。主振荡功率放大(MOPA)结构是实现光纤激光大功率输出的常用结构，这种结构通常由振荡器和一级放大器或者更多级放大器组成。基于熔融拉锥技术的光纤泵浦/信号合束器(tapered fiber bundle，简称TFB合束器)可以将信号光与泵浦光高效的耦合进入光纤放大器的双包层光纤中，因此TFB合束器已经成为实现MOPA结构大功率激光输出的核心元器件。
在高功率激光输入的情况下，合束器内部由损耗光导致的热效应越来越显著，使合束器内部产生温升。当温度足够高时，将使合束器在结构上失效。因此降低合束器内部损耗，减少温升，提高合束器可以承受的极限功率，已经成为进一步提高光纤激光器功率的关键之一。合束器内部温升主要来自于对损耗光的吸收，其中损耗光包括：泵浦光损耗光和信号光损耗光。通常情况下后者是造成合束器温升的重要原因，而信号光损耗光主要在拉锥区和熔接点处产生。
目前已有泵浦/信号合束器的相关专利，US7373070B2号美国专利文献公开了一种强拉锥结构泵浦/信号合束器，该泵浦/信号合束器的输入信号光纤与输出光纤均是纤芯为20微米、内包层为400微米、数值孔径为0.06/0.46的双包层光纤(以下简称20/400光纤)，泵浦光纤是纤芯为200微米、包层为220微米、数值孔径为0.22的单包层光纤。这种合束器需要先将输入信号光纤的包层进行化学刻蚀，将其内包层外径变为约200微米以便与泵浦光纤扭转形成光纤组束，为了保证光纤组束能与输出光纤尺寸匹配，要对光纤组束进行强拉锥(拉锥比例1.65)。该专利文献所采用的20/400光纤的纤芯支持LP01与LP11两个模式，由于拉锥比例为1.65，导致这种合束器对于LP11模式的损耗很大(2dB)。强拉锥结构合束器在主振荡功率放大(MOPA)结构光纤激光器的应用方面有不足之处：(1)LP01模式损耗较大，在高功率信号光输入时并不理想。前述美国专利是基于降低LP01模式损耗而设计，即通过拉锥，改变输入信号光纤纤芯的模场直径(MFD)，使其等于输出光纤纤芯的MFD，以此实现LP01模式的光学匹配和低损耗，然而即使在模场直径匹配条件满足的情况下，熔接点处LP01模式的损耗仍有0.25至0.3dB，在高功率信号光输入时并不理想；(2)高阶模 式损耗很大或无法耦合进入输出光纤纤芯，这会导致合束器损坏与激光器效率的下降，进一步限制最终输出激光功率的提升。在前述美国专利中指出，熔点处LP01模式损耗的增加不仅带来更多的废热，同时会导致输出光纤中的模式退化，即高阶模式的产生。这导致在后续的光纤振荡器或光纤放大器的增益光纤中，这些高阶模式会与LP01模式产生干涉，引发增益不稳定。增益不稳定会导致脉冲激光的产生，这些脉冲激光的峰值功率会超过光纤纤芯材料的破坏阈值，最终导致纤芯的损毁。因此，前述美国专利的核心理念是在降低LP01模式损耗的同时，保证高阶模式不进入输出光纤的纤芯，即高阶模式在合束器内部的损耗很大。实际上，前述美国专利公开的合束器由于拉锥比例过大，高阶模式在拉锥区已经进入输入信号光纤的内包层，而且在熔接点处模场失配严重，损耗很大。虽然前述美国专利中提出抑制高阶模式进入输出光纤可以避免脉冲激光的产生从而保护光纤激光器，但是高阶模式在合束器内部因损耗很大而产生的大量损耗光却会导致合束器内部产生更多废热，这严重影响了合束器的安全运行甚至会损坏合束器，并且合束器因为损耗光导致的的破坏阈值低于脉冲光产生的纤芯材料破坏阈值。此外，采用纤芯支持少数模式的大模场光纤搭建的光纤激光器，在输出光功率较高的情况下，其输出光中大多会包含少数的高阶模式，如果采用前述美国专利所述的合束器进一步放大包含少数高阶模式的光纤激光，将会导致高阶模式全部损耗而引起激光器的最终输出效率下降。
【发明内容】
本发明要解决的技术问题是克服现有技术的不足，提供一种可降低信号光的损耗、用于包含少数高阶模式的光纤激光功率放大的大功率弱拉锥低损耗泵浦/信号合束器。
为解决上述技术问题，本发明采用以下技术方案：
一种大功率弱拉锥低损耗泵浦/信号合束器，所述泵浦/信号合束器包括输出光纤、输入信号光纤和至少一根泵浦光纤，所述输入信号光纤的一端与所述泵浦光纤的一端通过熔融拉锥结合为一带有拉锥区的光纤组束，拉锥比例为1～1.45，所述光纤组束与所述输出光纤通过端面熔接。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述输出光纤和所述输入信号光纤均为双包层光纤，所述泵浦光纤为单包层光纤。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述光纤组束上的拉锥区末端(与输出光纤熔接处)外径不大于所述输出光纤的内包层外径。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述输出光纤的内包层外径为500微米～800微米。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述输出光纤的纤芯直径不 小于所述输入信号光纤的纤芯直径。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述输出光纤的纤芯直径为25微米～40微米，所述输入信号光纤的纤芯直径为20微米～30微米。二者纤芯直径的选取是以输出光纤的纤芯直径不小于输入信号光纤的纤芯直径为前提的。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述输出光纤的纤芯数值孔径不小于所述输入信号光纤的纤芯数值孔径。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述输出光纤的纤芯数值孔径为0.06～0.08，所述输入信号光纤的纤芯数值孔径为0.06～0.07。二者纤芯数值孔径的选取是以输出光纤的纤芯数值孔径不小于所述输入信号光纤的纤芯数值孔径为前提的。
上述的大功率弱拉锥低损耗泵浦/信号合束器中，优选的，所述泵浦光纤为6根。
本发明中，拉锥比例是指光纤组束在拉锥区起始点处的外切圆直径与光纤组束在拉锥区末端(与输出光纤熔接处)的外径之比，即拉锥区首尾外径之比。
本发明中，少数高阶模式通常是指输入信号光纤纤芯中支持的一个或几个高阶模式，具体情况取决于输入信号光纤纤芯的直径与数值孔径以及输入信号激光的光束质量。
与现有技术相比，本发明的优点在于：
1、本发明的泵浦/信号合束器使拉锥比例降低至1至1.45之间，实现了较弱拉锥或不拉锥，保证了泵浦光的低损耗，同时大幅度降低了高阶模式信号光的损耗，并进一步降低了LP01模式信号光的损耗。由于在较弱拉锥或不拉锥的情况下，LP01模式与高阶模式的拉锥区损耗和熔接点损耗都很低，本发明的泵浦/信号合束器可用于包含少数高阶模式的光纤激光的功率放大。
2、本发明的泵浦/信号合束器中输出光纤的纤芯直径不小于输入信号光纤的纤芯直径，以保证输出光纤的纤芯/包层面积比不降低，达到不降低后续光纤放大器的泵浦光吸收系数之目的。双包层光纤的纤芯/包层面积比对泵浦光的吸收有重要影响，一般而言，纤芯/包层面积比与泵浦光的吸收系数成正比。若纤芯/包层面积比较小，在保持掺杂浓度不变的条件下，则需要更长的增益光纤来保证对泵浦光的充分吸收，而这可能导致在光纤放大器中产生非线性效应，限制输出功率的提高。
3、本发明的泵浦/信号合束器的输出光纤的纤芯数值孔径不小于输入信号光纤的纤芯数值孔径，可进一步减小熔接点处模场失配损耗。因为增大输出光纤纤芯的数值孔径会在输出光纤纤芯中引入高阶模式，高阶模式参与模式耦合可以降低熔接点损耗。
【附图说明】
图1为本发明实施例中泵浦/信号合束器(即25/250-30/600弱拉锥合束器)的结构示 意图。
图2为本发明实施例的图1中A-A横截面示意图，即光纤组束的横截面示意图。
图3为本发明实施例2中泵浦/信号合束器的LP11模式的拉锥区损耗与拉锥比例的关系图。
图4为本发明实施例3中泵浦/信号合束器的熔接点损耗与输出光纤纤芯数值孔径的关系图。
图例说明：
1、泵浦光纤；2、输入信号光纤；3、输出光纤；4、拉锥区；5、熔接点。
【具体实施方式】
以下结合说明书附图和具体优选的实施例对本发明作进一步描述，但并不因此而限制本发明的保护范围。
实施例1：
一种本发明的大功率弱拉锥低损耗泵浦/信号合束器，如图1和图2所示，该泵浦/信号合束器包括1根输出光纤3、1根输入信号光纤2和6根泵浦光纤1，输入信号光纤2的一端(端部仅保留纤芯和内包层)与泵浦光纤1的一端通过熔融拉锥结合为一带有拉锥区4的光纤组束，拉锥比例为1.21，光纤组束经切割后与输出光纤3通过端面熔接于熔接点5处。
本实施例中，输出光纤3为双包层光纤，该输出光纤3的纤芯直径为30μm，内包层外径为600μm，纤芯/内包层的数值孔径为0.07/0.46。
本实施例中，输入信号光纤2为双包层光纤，该输入信号光纤2的纤芯直径为25μm，内包层外径为250μm，纤芯/内包层的数值孔径为0.06/0.46。
本实施例中，泵浦光纤1为单包层光纤，该单包层光纤的纤芯直径为200μm，包层直径为220μm，纤芯数值孔径为0.22。
本实施例中，如图1中两虚线间的区域所示，拉锥区4的长度为1cm。
实施例2：
为研究拉锥比例与拉锥区损耗的关系，本实施例制备了输入信号光纤2的纤芯直径分别为20μm和25μm时的不同拉锥比例的泵浦/信号合束器，泵浦/信号合束器的其它结构参数与实施例1的结构参数相同。如图3所示，是本实施例的泵浦/信号合束器在拉锥区4长度为1cm时，LP11模式信号光在拉锥区4的损耗与拉锥比例的关系，其中输入信号光纤2的纤芯直径分别为20μm和25μm，两种光纤的纤芯数值孔径均为0.06。两种输入信号光纤2均可通过常规合理的光纤盘绕实现较好的模式控制，即只输出两个模式：LP01模式 与LP11模式，因此本实施例的合束器是基于降低LP01和LP11两个模式的损耗而设计的。由于LP01模式基本可以无损通过拉锥区4，而LP11模式的损耗对拉锥比例的响应非常敏感，故在图3中只给出LP11模式与拉锥比例在两种具有不同纤芯直径的输入信号光纤2中的关系。由图3可知，当拉锥比例在1～1.45之间时，LP11模式的拉锥区损耗均小于0.2dB，特别是对于纤芯为25μm的情况，LP11模式在拉锥区4基本无损耗。而背景技术所提专利(US7373070B2)公开的强拉锥结构泵浦/信号合束器，其对应的拉锥比例为1.65，LP11模式的损耗为2dB，远大于本实施例的LP11模式拉锥区损耗。
实施例3：
为研究输出光纤3的纤芯数值孔径与熔接点损耗的关系，本实施例制备了不同输出光纤纤芯数值孔径的泵浦/信号合束器，除输出光纤纤芯数值孔径外，泵浦/信号合束器的其它结构参数与实施例1的结构参数相同。考虑到输入信号光模式只有LP01模式和LP11模式，如图4所示，给出了LP01模式和LP11模式经过熔接点5时的损耗，当输出光纤3的纤芯数值孔径为0.06时，在输出光纤3中有LP01、LP02、LP11模式参与耦合，这时，LP01模式的损耗已经足够低(0.02dB)，而LP11模式的熔接点损耗有0.46dB。当数值孔径逐渐增大时，两个模式的熔接点损耗逐渐减低，当数值孔径大于0.062时，输出光纤3的纤芯中将支持LP12模式，这时LP11模式熔接点损耗迅速下降，当数值孔径增至0.07时，LP11模式的熔接点损耗降至0.13dB。若输出光纤3的纤芯数值孔径过大，将在输出光纤纤芯中引入更高阶的模式，虽然熔接点5处的损耗将进一步降低，但输出激光的光束质量将会迅速恶化。因此为了保持输出光的光束质量，输出光纤3的纤芯数值孔径不能过大。
以上所述仅是本发明的优选实施方式，本发明的保护范围并不仅局限于上述实施例。凡属于本发明思路下的技术方案均属于本发明的保护范围。应该指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下的改进和润饰，这些改进和润饰也应视为本发明的保护范围。

Claims (9)

  1. 一种大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述泵浦/信号合束器包括输出光纤、输入信号光纤和至少一根泵浦光纤，所述输入信号光纤的一端与所述泵浦光纤的一端通过熔融拉锥结合为一带有拉锥区的光纤组束，拉锥比例为1～1.45，所述光纤组束与所述输出光纤通过端面熔接。
  2. 根据权利要求1所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述输出光纤和所述输入信号光纤均为双包层光纤，所述泵浦光纤为单包层光纤。
  3. 根据权利要求2所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述光纤组束上的拉锥区末端外径不大于所述输出光纤的内包层外径。
  4. 根据权利要求3所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述输出光纤的内包层外径为500微米～800微米。
  5. 根据权利要求1～4中任一项所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述输出光纤的纤芯直径不小于所述输入信号光纤的纤芯直径。
  6. 根据权利要求5所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述输出光纤的纤芯直径为25微米～40微米，所述输入信号光纤的纤芯直径为20微米～30微米。
  7. 根据权利要求1～4中任一项所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述输出光纤的纤芯数值孔径不小于所述输入信号光纤的纤芯数值孔径。
  8. 根据权利要求7所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述输出光纤的纤芯数值孔径为0.06～0.08，所述输入信号光纤的纤芯数值孔径为0.06～0.07。
  9. 根据权利要求1～4中任一项所述的大功率弱拉锥低损耗泵浦/信号合束器，其特征在于，所述泵浦光纤为6根。
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Families Citing this family (8)

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Publication number Priority date Publication date Assignee Title
CN104280822B (zh) * 2014-10-31 2015-08-05 中国人民解放军国防科学技术大学 大功率弱拉锥低损耗泵浦/信号合束器
CN104901155B (zh) * 2015-06-17 2018-07-13 中国人民解放军国防科学技术大学 一种高功率光纤激光泵浦光耦合与信号光扩束输出装置
CN105116494A (zh) * 2015-09-28 2015-12-02 珠海光库科技股份有限公司 泵浦合束器及其制作方法
CN105633779B (zh) * 2016-03-28 2018-07-20 中国人民解放军国防科学技术大学 用于光纤放大器的光纤端面泵浦耦合器及其制作方法
CN107134710A (zh) * 2017-06-19 2017-09-05 中科先为激光科技（北京）有限公司 端面泵浦耦合器及其制备方法
CN110429464A (zh) * 2019-07-19 2019-11-08 东莞理工学院 一种高功率激光器合束器
CN113820787A (zh) * 2021-08-19 2021-12-21 江苏亨通光纤科技有限公司 一种单模多模调模器件及其制备方法
CN115657211A (zh) * 2022-09-27 2023-01-31 深圳大学 一种基于端面泵浦的中红外光纤合束器及其制作方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7272956B1 (en) * 2004-07-30 2007-09-25 Coherent, Inc. Method for manufacturing a multimode fiber pump power combiner
CN102778729A (zh) * 2012-07-31 2012-11-14 清华大学 高光束质量信号光光纤合束器及其制作方法
CN103412369A (zh) * 2013-08-21 2013-11-27 西安中科汇纤光电科技有限公司 一种光纤合束器及其制备方法
US8818151B1 (en) * 2009-08-03 2014-08-26 United States Of America As Represented By The Secretary Of The Air Force Fiber Pump Signal Combiner
CN104280822A (zh) * 2014-10-31 2015-01-14 中国人民解放军国防科学技术大学 大功率弱拉锥低损耗泵浦/信号合束器

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6397636B1 (en) * 1999-05-20 2002-06-04 Lucent Technologies Inc. Method of applying a precursor to an assembled fiber bundle and fusing the bundle together
WO2006076524A2 (en) * 2005-01-14 2006-07-20 Comcore Technologies Inc. Tapered fiber bundles and devices
CN100427979C (zh) * 2007-01-05 2008-10-22 烽火通信科技股份有限公司 激光功率集成器及其实现方法
JP5649973B2 (ja) * 2007-12-14 2015-01-07 ロフィン−ジナール レーザー ゲゼルシャフト ミット ベシュレンクテル ハフツング 光ファイバへの光結合手段とカプラ製造方法
JP5584280B2 (ja) * 2012-12-21 2014-09-03 株式会社フジクラ ブリッジファイバ、コンバイナ及びファイバレーザ装置
CN103149638A (zh) * 2013-03-22 2013-06-12 清华大学 光纤耦合器

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7272956B1 (en) * 2004-07-30 2007-09-25 Coherent, Inc. Method for manufacturing a multimode fiber pump power combiner
US8818151B1 (en) * 2009-08-03 2014-08-26 United States Of America As Represented By The Secretary Of The Air Force Fiber Pump Signal Combiner
CN102778729A (zh) * 2012-07-31 2012-11-14 清华大学 高光束质量信号光光纤合束器及其制作方法
CN103412369A (zh) * 2013-08-21 2013-11-27 西安中科汇纤光电科技有限公司 一种光纤合束器及其制备方法
CN104280822A (zh) * 2014-10-31 2015-01-14 中国人民解放军国防科学技术大学 大功率弱拉锥低损耗泵浦/信号合束器

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