阅读说明：本技术 一种基于环形腔结构的皮秒种子激光器 (Picosecond seed laser based on annular cavity structure ) 是由 马英俊 张鹏 杨春宝 于 2021-09-16 设计创作，主要内容包括：本发明提供了一种基于环形腔结构的皮秒种子光纤激光器,包括泵浦源和环形腔,所述环形腔包括波分复用器、光纤环形器、光纤耦合器；所述泵浦源与所述波分复用器连接,将泵浦光耦合进入环形腔；所述波分复用器的第一端口与所述光纤环形器的第一端口之间连接有增益光纤；所述光纤环形器的第二端口连接有半导体可饱和吸收镜,作为激光器的锁模器件；所述光纤环形器的第三端口与所述光纤耦合器的输入端之间设有声光调制器；所述光纤耦合器的第一输出端与所述波分复用器的第二端口连接,构成环形腔结构,所述光纤耦合器的第二输出端与激光器输出终端连接,将皮秒脉冲激光输出。本发明的种子光纤激光器,采用了环形腔结构,泵浦源的能量被充分吸收,转换效率较高；且在环形腔中使用半导体可饱和吸收镜,更容易实现锁模,获得超短激光脉冲；同时结合调制器件,更容易对激光频率进行调制；从而避免使用线形腔结构而带来的输出功率低、谱线较宽等问题。(The invention provides a picosecond seed optical fiber laser based on an annular cavity structure, which comprises a pumping source and an annular cavity, wherein the annular cavity comprises a wavelength division multiplexer, an optical fiber circulator and an optical fiber coupler; the pumping source is connected with the wavelength division multiplexer and used for coupling pumping light into the annular cavity; a gain optical fiber is connected between the first port of the wavelength division multiplexer and the first port of the optical fiber circulator; the second port of the optical fiber circulator is connected with a semiconductor saturable absorber mirror which is used as a mode locking device of the laser; an acousto-optic modulator is arranged between the third port of the optical fiber circulator and the input end of the optical fiber coupler; and the second output end of the optical fiber coupler is connected with the laser output terminal to output picosecond pulse laser. The seed optical fiber laser adopts the annular cavity structure, so that the energy of a pumping source is fully absorbed, and the conversion efficiency is higher; a semiconductor saturable absorption mirror is used in the annular cavity, so that mode locking is realized more easily, and ultrashort laser pulses are obtained; meanwhile, the laser frequency is easier to modulate by combining with a modulation device; thereby avoiding the problems of low output power, wide spectral line and the like caused by using a linear cavity structure.)

1. A picosecond seed optical fiber laser based on an annular cavity structure comprises a pumping source and an annular cavity; the ring cavity comprises a wavelength division multiplexer, an optical fiber circulator and an optical fiber coupler; the wavelength division multiplexer comprises two ports in an annular cavity structure, the optical fiber circulator comprises three ports, and the optical fiber coupler is a 1-x 2 type optical fiber coupler; the pumping source is connected with the wavelength division multiplexer and used for coupling pumping light into the annular cavity; a gain optical fiber is connected between the first port of the wavelength division multiplexer and the first port of the optical fiber circulator; the second port of the optical fiber circulator is connected with a semiconductor saturable absorber mirror which is used as a mode locking device of the laser; an acousto-optic modulator is arranged between the third port of the optical fiber circulator and the input end of the optical fiber coupler; and the second output end of the optical fiber coupler is connected with the laser output terminal to output picosecond pulse laser.

2. The picosecond seed fiber laser based on ring cavity structure of claim 1, wherein the pump source is a wavelength-locked pump source.

3. The picosecond seed fiber laser based on ring cavity structure of claim 1, wherein the wavelength division multiplexer is a wave plate type wavelength division multiplexer.

4. The picosecond seed fiber laser based on ring cavity structure of claim 4, wherein the laser output terminal is bare fiber output, jumper output or collimated output.

5. The picosecond seed fiber laser based on ring cavity structure of claim 1, wherein the laser output terminal further comprises an optical isolator for isolating the return light.

Technical Field

The invention belongs to the technical field of laser, and relates to a picosecond seed laser based on an annular cavity structure.

Background

Ultrashort pulse laser benefits from the characteristics of high peak power, high repetition frequency, narrow pulse width and the like, and is widely applied to the fields of industrial fine processing, laser medical treatment, cosmetology, optical communication and the like. In order to obtain ultrashort pulse output, mode locking modes are usually adopted, including various mode locking modes such as active mode locking, passive mode locking, active and passive mode locking, and self-mode locking. The passive mode locking technology based on the semiconductor saturable absorption mirror is widely applied by people due to the characteristics of flexible design and stable system.

For the resonant cavity of the laser, the fiber laser can be divided into a linear cavity structure and a ring cavity structure from the structural division. For a line cavity structure, the fiber laser based on the Fabry-Perot cavity structure has the defect of wide laser spectrum width. With the gradual maturity of the fiber grating technology, the bragg reflection fiber grating laser (DBR) and the distributed feedback fiber laser (DFB) which are applicable to the linear cavity structure have the characteristics of simple structure and good compatibility, are more and more emphasized, and are gradually used in the linear cavity to solve the problem of wide laser spectrum width. However, in the use process of a bragg reflection fiber grating laser (DBR), optical feedback and wavelength selection are realized by two gratings, so that the output wavelength is difficult to determine; and the fiber laser with the linear cavity structure has low output power due to the short resonant cavity and low pump absorption rate and slope efficiency. And the picosecond seed laser based on the annular cavity structure benefits from the annular cavity structure, the pumping energy is fully absorbed, the conversion efficiency is high, and mode locking and modulation are easy to realize.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention proposes a specific technical solution as follows.

A picosecond seed optical fiber laser based on an annular cavity structure comprises a pumping source and an annular cavity; the annular cavity comprises a wavelength division multiplexer, an optical fiber circulator and an optical fiber coupler; the wavelength division multiplexer comprises two ports in an annular cavity structure, the optical fiber circulator comprises three ports, and the optical fiber coupler is a 1-x 2 type optical fiber coupler; the pumping source is connected with the wavelength division multiplexer and used for coupling pumping light into the annular cavity; a gain optical fiber is connected between the first port of the wavelength division multiplexer and the first port of the optical fiber circulator; the second port of the optical fiber circulator is connected with a semiconductor saturable absorber mirror which is used as a mode locking device of the laser; an acousto-optic modulator is arranged between the third port of the optical fiber circulator and the input end of the optical fiber coupler; and the second output end of the optical fiber coupler is connected with the laser output terminal to output picosecond pulse laser.

Preferably, the pump source is a wavelength-locked pump source.

Preferably, the wavelength division multiplexer is a wave plate type wavelength division multiplexer.

Preferably, the laser output terminal is bare fiber output, jumper output or collimation output.

Preferably, the laser output terminal further comprises an optical isolator for isolating the return light.

The seed optical fiber laser adopts the annular cavity structure, so that the energy of a pumping source is fully absorbed, and the conversion efficiency is higher; a semiconductor saturable absorption mirror is used in the annular cavity, so that mode locking is realized more easily, and ultrashort laser pulses are obtained; meanwhile, the laser frequency is easier to modulate by combining with a modulation device; thereby avoiding the problems of low output power, wide spectral line and the like caused by using a linear cavity structure.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a structural diagram of a picosecond seed fiber laser based on a ring cavity structure according to the present invention.

1-pumping source, 2-wavelength division multiplexer, 3-gain fiber, 4-three-port fiber circulator, 5-semiconductor saturable absorber mirror, 6-acousto-optic modulator, 7-fiber coupler and 8-optical isolator.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Description figure 1 is a structure diagram of a picosecond seed optical fiber laser based on a ring cavity structure.

As shown in fig. 1, a picosecond seed fiber laser based on a ring cavity structure comprises a pump source 1 and a ring cavity; the annular cavity consists of a wavelength division multiplexer 2, an optical fiber circulator 4 and an optical fiber coupler 7; the pumping source 1 is connected with the wavelength division multiplexer 2, and the pumping light is coupled into the annular cavity and used as a gain excitation source of the laser; the wavelength division multiplexer comprises two ports in an annular cavity structure, the optical fiber circulator 4 comprises three ports, and a doped optical fiber 3 is connected between a first port of the wavelength division multiplexer 2 and a first port of the optical fiber circulator 4 and is used as a gain medium of the picosecond optical fiber laser; the second port of the optical fiber circulator 4 is connected with a semiconductor saturable absorber mirror 5, and the semiconductor saturable absorber mirror 5 is used as a mode locking device of the optical fiber laser to realize the compression of the laser pulse width; an acousto-optic modulator 6 is arranged between the third port of the optical fiber circulator 4 and the optical fiber coupler 7 and is used for modulating the laser frequency; the optical fiber coupler 7 is of a 1 x 2 type structure, a first output end of the optical fiber coupler is connected with a second port of the wavelength division multiplexer 2 to form an annular cavity structure, and a second output end of the optical fiber coupler is connected with a laser output terminal and used for leading out picosecond pulse laser according to a preset proportion.

In this embodiment, the pump source 1 may be a wavelength-locked pump source for providing laser excitation.

In this embodiment, the wavelength division multiplexer 2 is a wave-plate type wavelength division multiplexer, and the pump light output by the pump source 1 is coupled into the doped optical fiber 3 from the output end of the wavelength division multiplexer 2.

In this embodiment, the laser output terminal further includes an optical isolator for isolating the returned light.

In this embodiment, the laser output terminal may be a bare fiber output, a jumper output, or a collimated output.

The working principle of the fiber laser in the embodiment is as follows: the whole laser is an annular cavity structure comprising a wavelength division multiplexer 2, a three-port optical fiber circulator 4 and an optical fiber coupler 7; after passing through a wavelength division multiplexer 2, light output by a pumping source 1 enters a doped optical fiber 3 through the coupling of a first port of the wavelength division multiplexer 2, the other end of the doped optical fiber 3 is connected with a first port of an optical fiber circulator 4, a second port of the optical fiber circulator 4 is connected with a semiconductor saturable absorber mirror 5, pulse compression is carried out on the laser through the semiconductor saturable absorber mirror 5, picosecond laser is obtained, the obtained picosecond laser is output through a third port of the optical fiber circulator 4 and enters an acousto-optic modulator 6 to be subjected to laser frequency modulation, and finally, a first output end of an optical fiber coupler 7 is connected to an output terminal of the laser, and an optical isolator 8 is arranged at the output terminal of the laser and used for isolating return light; and a second output end of the optical fiber coupler 7 is connected with a second port of the wavelength division multiplexer to form a ring cavity structure.

In the embodiment, the seed fiber laser with the annular cavity structure is adopted, and the length of the resonant cavity is longer, so that the energy of a pumping source can be fully absorbed, the conversion efficiency is higher, and higher laser output power can be realized; the use of semiconductor saturable absorption mirrors and modulation devices in the ring cavity makes mode locking and laser modulation easier to achieve, thereby obtaining ultrashort laser pulses at the desired frequency. The problems of low output power, wide spectral line and the like caused by the use of a linear cavity structure are avoided.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.