阅读说明：本技术 三倍布里渊频移间隔的多波长布里渊光纤激光器 (Multi-wavelength Brillouin optical fiber laser with triple Brillouin frequency shift interval ) 是由 刘铁园 徐荣辉 牛国振 邓仕杰 陈明 苑立波 于 2020-07-20 设计创作，主要内容包括：本文公开了一种三倍布里渊频移间隔的多波长布里渊光纤激光器。包括可调激光器(1)、第一光纤耦合器(2)、第一光环形器(3)、第一光放大器(4)、第一布里渊光纤(5)、第二光纤耦合器(6)、第二光放大器(7)、第二布里渊光纤(8)和第二光环形器(9)。可调激光器用作布里渊泵浦,利用两个光放大器的功率增益,在第一布里渊光纤和第二布里渊光纤中循环发生级联受激布里渊散射,可产生三倍布里渊频移间隔的多波长布里渊光纤激光器。该多波长布里渊光纤激光器方法装置结构简单、成本低,在光通信、微波光子及光纤传感中均具有应用潜力。(A triple Brillouin frequency shifted spaced multi-wavelength Brillouin fiber laser is disclosed. The Brillouin optical fiber amplifier comprises a tunable laser (1), a first optical fiber coupler (2), a first optical circulator (3), a first optical amplifier (4), a first Brillouin optical fiber (5), a second optical fiber coupler (6), a second optical amplifier (7), a second Brillouin optical fiber (8) and a second optical circulator (9). The tunable laser is used as Brillouin pumping, and by utilizing the power gains of the two optical amplifiers, cascade stimulated Brillouin scattering circularly occurs in the first Brillouin optical fiber and the second Brillouin optical fiber, so that the multi-wavelength Brillouin optical fiber laser with triple Brillouin frequency shift interval can be generated. The method and the device for the multi-wavelength Brillouin optical fiber laser have the advantages of simple structure and low cost, and have application potential in optical communication, microwave photon and optical fiber sensing.)

1. A multi-wavelength Brillouin optical fiber laser with triple Brillouin frequency shift interval comprises a tunable laser (1), a first optical fiber coupler (2), a first optical circulator (3), a first optical amplifier (4), a first Brillouin optical fiber (5), a second optical fiber coupler (6), a second optical amplifier (7), a second Brillouin optical fiber (8) and a second optical circulator (9).

2. The triple brillouin frequency shift spaced multiple wavelength brillouin fiber laser of claim 1, wherein: the output end of the tunable laser (1) is connected with one port (21) of a first optical fiber coupler (2), the two ports (22) of the first optical fiber coupler (2) are connected with one port (31) of a first optical circulator (3), the second port (32) of the first optical circulator is connected with one end of a first optical amplifier (4), the other end of the first optical amplifier (4) is connected with one end of a first Brillouin optical fiber (5), the other end of the first Brillouin optical fiber (5) is connected with the third port (33) of the first optical circulator (3), the four port (34) of the first optical circulator (3) is connected with one port (61) of a second optical fiber coupler (6), the two ports (62) of the second optical fiber coupler (6) are connected with one end of a second optical amplifier (7), and the other end of the second optical amplifier (7) is connected with one end of a second Brillouin optical fiber (8), the other end of the second Brillouin optical fiber (8) is connected with two ports (92) of a second optical circulator (9), three ports (93) of the second optical circulator are connected with one port (91), three ports (63) of the second optical fiber coupler (6) are connected with three ports (23) of the first optical fiber coupler (2), and a four port (24) of the first optical fiber coupler is used as an output port of the multi-wavelength Brillouin optical fiber laser and can be connected with an optical spectrum analyzer.

3. The triple brillouin frequency shift spaced multiple wavelength brillouin fiber laser of claim 1, wherein: the tunable laser is used as a Brillouin Pump (BP), after the BP is split by the first optical fiber coupler, a part of the BP is output from four ports of the first optical fiber coupler, a part of the BP enters the first optical amplifier through the optical paths 21-22-31-32 to be amplified, the amplified BP enters the first Brillouin optical fiber and generates Brillouin scattering with the first Brillouin optical fiber, when the BP power reaches a stimulated Brillouin scattering threshold value of the first Brillouin optical fiber, stimulated Brillouin scattering is generated, first-order Stokes which are transmitted backwards relative to the BP and are subjected to frequency shift downwards is generated (S1), S1 is amplified by the first optical amplifier, then enters the first Brillouin optical fiber through the two ports and the three ports of the optical circulator and generates Brillouin scattering with the first Brillouin optical fiber, when the S1 power is enough, the stimulated Brillouin scattering is generated, second-order Stokes which are transmitted backwards relative to S1 and are subjected to frequency shift downwards (S2), s2 enters a second optical amplifier (7) along the optical paths 33-34-61-62 for amplification, the amplified S2 is injected into one end of the second Brillouin optical fiber and generates Brillouin scattering with the end, when the power of S2 is enough, the stimulated Brillouin scattering is generated, three-order Stokes which are transmitted back relative to S2 and have Brillouin frequency shift shifted downwards in frequency are generated (S3), the second optical circulator can transmit S2 showing consumed forward transmission back to the second Brillouin optical fiber to enhance S3, after S3 is amplified by the second optical amplifier, a part of S3 is output from the four ports of the first optical fiber coupler along the optical paths 62-63-23-24, another part of S3 enters the first Brillouin optical fiber through the first optical circulator, and the stimulated Brillouin scattering in the first Brillouin optical fiber and the second optical fiber can circulate as long as the gains of the first optical amplifier and the second optical amplifier are larger than losses, at the four ends of the first fiber coupler, a third-order stokes (S3), a sixth-order stokes (S6), a ninth-order stokes (S9), etc., will occur, resulting in a triple brillouin frequency shift spaced multi-wavelength brillouin fiber laser.

4. The triple brillouin frequency shift spaced multiple wavelength brillouin fiber laser of claim 1, wherein: the first Brillouin gain fiber and the second Brillouin gain fiber are single-mode fibers with the same Brillouin frequency shift.

5. The triple brillouin frequency shift spaced multiple wavelength brillouin fiber laser of claim 1, wherein: the first optical amplifier and the second optical amplifier are both optical amplifiers capable of bidirectional optical amplification.

Technical Field

The invention belongs to the field of optical fiber lasers, and relates to a multi-wavelength Brillouin optical fiber laser with triple Brillouin frequency shift interval.

Background

Stimulated Brillouin Scattering (SBS) is a nonlinear optical effect generated by optical waves and acoustic waves through electrostrictive interaction, and can be easily cascaded in an optical fiber at room temperature to realize multi-wavelength Brillouin signal output. The advantages of fixed wavelength interval, low threshold, narrow line width, high optical power conversion effect, compact structure and the like of the multi-wavelength Brillouin fiber laser are widely researched by researchers at home since birth. Cowle and Stapanov first proposed a method of combining linear gain in erbium doped fiber with nonlinear brillouin gain in single mode fiber in 1996 and obtained 6 wavelength outputs at intervals of 10GHz, representing the birth of a multi-wavelength brillouin erbium doped fiber laser. In 1997, Stepanov and Cowle improved the external cascade experimental structure, and 30 Brillouin wavelength outputs at intervals of 10GHz were obtained in the experiment. Lim et al used the stimulated brillouin scattering and the four-wave mixing effect in 1998 to obtain 34 brillouin stokes and anti-stokes light outputs. Through the development of years, Mohammed H.Al-Mansori et al in 2006 realized the low-threshold L-band Brillouin multi-wavelength generation of 23.4mW output power by using a two-way amplification linear cavity structure. In 2009, Ajiya et al used 130mW brillouin pumping and 2mW 1480 pumping power to obtain 39nm tunable multi-wavelength brillouin laser in a C-band in an 11km long dispersion shifted fiber. In 2013, Al-Alimi et Al, university of Bradela, Malaysia, constructed a movable virtual mirror in the laser structure, and utilized the four-wave mixing effect in a 2km long high nonlinear optical fiber to obtain 150 Brillouin multi-wavelength outputs adjustable in the 40nm range. Wang et al in recent years have used two SBS effect cavities to compensate by double erbium doped fiber amplifiers to obtain multiple wavelength outputs. The multi-wavelength brillouin laser generator has been developed and advanced greatly, but the dispersion displacement optical fiber and the high nonlinear optical fiber are more expensive than the single-mode ordinary optical fiber, the manufacturing cost of the laser is increased, the number of chambers with the SBS effect is increased, the structural complexity of the system is increased undoubtedly, and the difficulty of adjusting and calibrating is also increased.

Since the brillouin scattering effect in optical fiber was discovered four decades ago, researchers at home and abroad have conducted extensive research and significant progress on their application in the aspects of brillouin fiber lasers, brillouin fiber sensors and microwave photon technology. Although there are many reports on multi-wavelength lasers with multiple brillouin frequency shift intervals, the requirements of the communication industry cannot be met due to the defects of complex structure, low system cost, wide tunable range and the like, so that it is necessary to research a multi-wavelength brillouin laser with low threshold power, low system cost and simple structure and with frequency shift interval greater than two times of brillouin frequency shift interval.

Disclosure of Invention

The invention provides a multi-wavelength Brillouin fiber laser with triple Brillouin frequency shift interval, which has the advantages of compact structure, low cost and small threshold power.

The following technical scheme is proposed for achieving the purpose:

a multi-wavelength Brillouin optical fiber laser with triple Brillouin frequency shift interval is characterized by comprising a tunable laser (1), a first optical fiber coupler (2), a first optical circulator (3), a first optical amplifier (4), a first Brillouin optical fiber (5), a second optical fiber coupler (6), a second optical amplifier (7), a second Brillouin optical fiber (8) and a second optical circulator (9);

the output end of the tunable laser (1) is connected with one port (21) of a first optical fiber coupler (2), the two ports (22) of the first optical fiber coupler (2) are connected with one port (31) of a first optical circulator (3), the second port (32) of the first optical circulator is connected with one end of a first optical amplifier (4), the other end of the first optical amplifier (4) is connected with one end of a first Brillouin optical fiber (5), the other end of the first Brillouin optical fiber (5) is connected with the third port (33) of the first optical circulator (3), the four port (34) of the first optical circulator (3) is connected with one port (61) of a second optical fiber coupler (6), the two ports (62) of the second optical fiber coupler (6) are connected with one end of a second optical amplifier (7), and the other end of the second optical amplifier (7) is connected with one end of a second Brillouin optical fiber (8), the other end of the second Brillouin optical fiber (8) is connected with two ports (92) of a second optical circulator (9), three ports (93) of the second optical circulator are connected with one port (91), three ports (63) of the second optical fiber coupler (6) are connected with three ports (23) of the first optical fiber coupler (2), and a four port (24) of the first optical fiber coupler is used as an output port of the multi-wavelength Brillouin optical fiber laser and can be connected with an optical spectrum analyzer.

The tunable laser is used as a Brillouin Pump (BP), after the BP is split by the first optical fiber coupler, a part of the BP is output from four ports of the first optical fiber coupler, a part of the BP enters the first optical amplifier through the optical paths 21-22-31-32 to be amplified, the amplified BP enters the first Brillouin optical fiber and generates Brillouin scattering with the first Brillouin optical fiber, when the BP power reaches a stimulated Brillouin scattering threshold value of the first Brillouin optical fiber, stimulated Brillouin scattering is generated, first-order Stokes which are transmitted backwards relative to the BP and are subjected to frequency shift downwards is generated (S1), S1 is amplified by the first optical amplifier, then enters the first Brillouin optical fiber through the two ports and the three ports of the optical circulator and generates Brillouin scattering with the first Brillouin optical fiber, when the S1 power is enough, the stimulated Brillouin scattering is generated, second-order Stokes which are transmitted backwards relative to S1 and are subjected to frequency shift downwards (S2), s2 enters a second optical amplifier (7) along the optical paths 33-34-61-62 for amplification, the amplified S2 is injected into one end of the second Brillouin optical fiber and generates Brillouin scattering with the end, when the power of S2 is enough, the stimulated Brillouin scattering is generated, three-order Stokes which are transmitted back relative to S2 and have Brillouin frequency shift shifted downwards in frequency are generated (S3), the second optical circulator can transmit S2 showing consumed forward transmission back to the second Brillouin optical fiber to enhance S3, after S3 is amplified by the second optical amplifier, a part of S3 is output from the four ports of the first optical fiber coupler along the optical paths 62-63-23-24, another part of S3 enters the first Brillouin optical fiber through the first optical circulator, and the stimulated Brillouin scattering in the first Brillouin optical fiber and the second optical fiber can circulate as long as the gains of the first optical amplifier and the second optical amplifier are larger than losses, at the four ends of the first fiber coupler, a third-order stokes (S3), a sixth-order stokes (S6), a ninth-order stokes (S9), etc., will occur, resulting in a triple brillouin frequency shift spaced multi-wavelength brillouin fiber laser.

The first Brillouin gain fiber and the second Brillouin gain fiber are single-mode fibers with the same Brillouin frequency shift, and the length of the optical fiber is generally 15-20 km.

The adjustable laser is a narrow linewidth adjustable laser with the linewidth lower than 1MHz, and the wavelength range of the laser is C waveband.

The first optical amplifier and the second optical amplifier are both optical fiber amplifiers capable of bidirectional optical amplification, and are generally optical fiber amplifiers formed by erbium-doped optical fiber amplifiers or other linear gain optical fibers, such as ytterbium-doped optical fibers and ytterbium-erbium co-doped optical fibers.

The invention has the advantages that:

the invention has simple structure, low power consumption, no need of high-power optical fiber amplifier and electro-optical modulator, low system cost, easy generation of laser signal and wide development prospect.

Drawings

FIG. 1 is a schematic diagram of an optical path structure of a triple Brillouin frequency shift spaced multi-wavelength Brillouin fiber laser.

The reference numerals in fig. 1 are interpreted as: 1-tunable laser, 2-first fiber coupler, 21-first fiber coupler first port, 22-first fiber coupler second port, 23-first fiber coupler third port, 24-first fiber coupler fourth port, 3-first optical circulator, 31-first optical circulator first port, 32-first optical circulator second port, 33-first optical circulator third port, 34-first optical circulator fourth port, 4-first optical amplifier, 5-first brillouin fiber, 6-second fiber coupler, 61-second fiber coupler port, 62-second fiber coupler second port, 63-second fiber coupler third port, 7-second optical amplifier, 8-second brillouin fiber, 9-second optical circulator, 91-first port of second optical circulator, 92-second port of second optical circulator, 93-third port of second optical circulator.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

A multi-wavelength Brillouin optical fiber laser with triple Brillouin frequency shift interval is characterized by comprising a tunable laser (1), a first optical fiber coupler (2), a first optical circulator (3), a first optical amplifier (4), a first Brillouin optical fiber (5), a second optical fiber coupler (6), a second optical amplifier (7), a second Brillouin optical fiber (8) and a second optical circulator (9); the output end of the tunable laser (1) is connected with one port (21) of a first optical fiber coupler (2), the two ports (22) of the first optical fiber coupler (2) are connected with one port (31) of a first optical circulator (3), the second port (32) of the first optical circulator is connected with one end of a first optical amplifier (4), the other end of the first optical amplifier (4) is connected with one end of a first Brillouin optical fiber (5), the other end of the first Brillouin optical fiber (5) is connected with the third port (33) of the first optical circulator (3), the four port (34) of the first optical circulator (3) is connected with one port (61) of a second optical fiber coupler (6), the two ports (62) of the second optical fiber coupler (6) are connected with one end of a second optical amplifier (7), and the other end of the second optical amplifier (7) is connected with one end of a second Brillouin optical fiber (8), the other end of the second Brillouin optical fiber (8) is connected with two ports (92) of a second optical circulator (9), three ports (93) of the second optical circulator are connected with one port (91), three ports (63) of the second optical fiber coupler (6) are connected with three ports (23) of the first optical fiber coupler (2), and a four port (24) of the first optical fiber coupler is used as an output port of the multi-wavelength Brillouin optical fiber laser and can be connected with an optical spectrum analyzer.

The tunable laser is used as a Brillouin Pump (BP), after the BP is split by the first optical fiber coupler, a part of the BP is output from four ports of the first optical fiber coupler, a part of the BP enters the first optical amplifier through the optical paths 21-22-31-32 to be amplified, the amplified BP enters the first Brillouin optical fiber and generates Brillouin scattering with the first Brillouin optical fiber, when the BP power reaches a stimulated Brillouin scattering threshold value of the first Brillouin optical fiber, stimulated Brillouin scattering is generated, first-order Stokes which are transmitted backwards relative to the BP and are subjected to frequency shift downwards is generated (S1), S1 is amplified by the first optical amplifier, then enters the first Brillouin optical fiber through the two ports and the three ports of the optical circulator and generates Brillouin scattering with the first Brillouin optical fiber, when the S1 power is enough, the stimulated Brillouin scattering is generated, second-order Stokes which are transmitted backwards relative to S1 and are subjected to frequency shift downwards (S2), s2 enters a second optical amplifier (7) along the optical paths 33-34-61-62 for amplification, the amplified S2 is injected into one end of the second Brillouin optical fiber and generates Brillouin scattering with the end, when the power of S2 is enough, the stimulated Brillouin scattering is generated, three-order Stokes which are transmitted back relative to S2 and have Brillouin frequency shift shifted downwards in frequency are generated (S3), the second optical circulator can transmit S2 showing consumed forward transmission back to the second Brillouin optical fiber to enhance S3, after S3 is amplified by the second optical amplifier, a part of S3 is output from the four ports of the first optical fiber coupler along the optical paths 62-63-23-24, another part of S3 enters the first Brillouin optical fiber through the first optical circulator, and the stimulated Brillouin scattering in the first Brillouin optical fiber and the second optical fiber can circulate as long as the gains of the first optical amplifier and the second optical amplifier are larger than losses, at the four ends of the first fiber coupler, a third-order stokes (S3), a sixth-order stokes (S6), a ninth-order stokes (S9), etc., will occur, resulting in a triple brillouin frequency shift spaced multi-wavelength brillouin fiber laser.

The first Brillouin gain fiber and the second Brillouin gain fiber are single-mode fibers with the same Brillouin frequency shift, and the length of the optical fiber is generally 15-20 km.

The adjustable laser is a narrow linewidth adjustable laser with the linewidth lower than 1MHz, and the wavelength range of the laser is C waveband.

The first optical amplifier and the second optical amplifier are both optical fiber amplifiers capable of bidirectional optical amplification, and are generally optical fiber amplifiers formed by erbium-doped optical fiber amplifiers or other linear gain optical fibers, such as ytterbium-doped optical fibers and ytterbium-erbium co-doped optical fibers.

The above detailed description of the working process of the present invention provides a person skilled in the art with the idea of the present invention that there may be variations in the specific implementation, and these variations should be considered as the protection scope of the present invention.