阅读说明：本技术 一种微波信号的光学产生装置 (Optical generation device for microwave signals ) 是由 徐荣辉 张先强 汪杰君 秦祖军 陈明 苑立波 于 2020-07-20 设计创作，主要内容包括：本发明公开了一种微波信号的光学产生装置,包括窄线宽可调激光器(1)、第一三端口光纤耦合器(2)、三端口光环形器(3)、第一光纤放大器(4),第一布里渊增益光纤(5)、第二三端口光纤耦合器(6)、第二光纤放大器(7)、第三三端口光纤耦合器(8),第二布里渊增益光纤(9),第四三端口光纤耦合器(10),光电探测器(11),窄线宽可调激光器输出的激光作为布里渊泵浦光,通过在第一布里渊增益光纤发生两次受激布里渊散射和第二布里渊增益光纤发生一次受激布里渊散射,通过光纤放大器的线性放大作用,可以产生三阶布里渊斯托克斯光,三阶斯托克斯光与第一三端口光纤耦合器中传输的泵浦光拍频,可以在光电探测器上得到微波信号。该光生微波信号的方法与结构简单,成本低,在光无线通信、微波光子及光纤传感中均具有应用前景。(The invention discloses an optical generation device of microwave signals, which comprises a narrow linewidth adjustable laser (1), a first three-port optical fiber coupler (2), a three-port optical circulator (3), a first optical fiber amplifier (4), a first Brillouin gain optical fiber (5), a second three-port optical fiber coupler (6), a second optical fiber amplifier (7), a third three-port optical fiber coupler (8), a second Brillouin gain optical fiber (9), a fourth three-port optical fiber coupler (10) and a photoelectric detector (11), wherein laser output by the narrow linewidth adjustable laser is used as Brillouin pumping light, the first Brillouin gain optical fiber generates twice stimulated Brillouin scattering and the second Brillouin gain optical fiber generates once stimulated Brillouin scattering, and third-order Brillouin Stokes light and pumping light transmitted in the first three-port optical fiber coupler beat frequency can be generated through the linear amplification effect of the optical fiber amplifiers, the microwave signal can be obtained on a photodetector. The method and the structure for generating the microwave signal are simple, the cost is low, and the method has application prospects in optical wireless communication, microwave photon and optical fiber sensing.)

1. An optical generation device for microwave signals comprises a narrow-linewidth adjustable laser (1), a first optical fiber coupler (2), a three-port 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 third optical fiber coupler (8), a second Brillouin optical fiber (9), a fourth optical fiber coupler (10) and a photoelectric detector (11).

2. The optical generation device of microwave signal, its characteristic is: the output end of the narrow linewidth adjustable laser (1) is connected with an A1 port at an A end of a first optical fiber coupler (2), a B1 port at a B end of the first optical fiber coupler (2) is connected with a first port (31) of a three-port optical circulator (3), a second port (32) of the three-port optical circulator (3) is connected with one end of a first optical fiber amplifier (4), the other end of the first optical amplifier is connected between one ends of first Brillouin optical fibers (5), the other end of the first Brillouin optical fibers (5) is connected with a C1 port at a C end of a second optical fiber coupler (6), a D1 port at a D end of the second optical fiber coupler (6) is connected with a third port (33) of the three-port optical circulator (3), a D2 port at a D end of the second optical fiber coupler (6) is connected with an input end of a second optical amplifier (7), and the output end of the second optical amplifier is connected with an F1 port at an F end of a third optical fiber coupler (8), an E1 port at the E end of the third optical fiber coupler (8) is connected with the second Brillouin optical fiber (9), an F2 port at the F end of the third optical fiber coupler (8) is connected with an H1 port at the H end of the fourth optical fiber coupler (10), an H2 port at the H end of the fourth optical fiber coupler (10) is connected with a B2 port at the B end of the first optical fiber coupler (2), a G1 port at the G end of the fourth optical fiber coupler (10) is connected with an input port of the photoelectric detector (11), and an output port of the photoelectric detector can be connected to a spectrum analyzer.

3. The optical generation device of microwave signal, its characteristic is: laser output by the narrow linewidth tunable laser is split by a first optical fiber coupler (2), a part of the laser is output by a port B2 to be used as beat frequency light, a part of the laser is output by a port B1 to be used as Brillouin pump light (BP), the BP enters a first optical amplifier for amplification by a three-port optical circulator, the amplified BP is injected into one end of the first Brillouin optical fiber and generates Brillouin scattering therein, when the power of the amplified BP is large enough, the stimulated Brillouin scattering can be generated to generate first-order Stokes light which is transmitted reversely with the BP and shifts in frequency by Brillouin frequency (S1), S1 is injected into the other end of the first Brillouin optical fiber by the three-port optical circulator and a second optical fiber coupler and generates Brillouin scattering therein, when the power of S1 is large enough, the stimulated Brillouin scattering can be generated to generate second-order Stokes light which is transmitted reversely with S1 and shifts in frequency by Brillouin frequency (S2), s2 is output from a D2 port at the D end of the second optical fiber coupler, amplified by the second optical amplifier, and then injected into the second Brillouin optical fiber (9) through the third optical fiber coupler, when the amplified S2 has enough power, stimulated Brillouin scattering occurs, third-order Stokes light (S3) which is transmitted in reverse direction with S2 and undergoes Brillouin frequency shift in frequency is generated, S3 is transmitted to an H1 port at the H end of the fourth optical fiber coupler through an F2 port at the F end of the third optical fiber coupler, beat frequency occurs in the fourth optical fiber coupler with BP from a B2 port of the first optical fiber coupler, the beat frequency is output to a photoelectric detector (11) through a G1 port of the fourth optical fiber coupler, photoelectric conversion is achieved, and microwave signals can be observed on spectrum analysis.

4. The optical generation device of microwave signal, its characteristic is: the first Brillouin optical fiber and the second Brillouin optical fiber are both single-mode quartz optical fibers with the length of 20km, and the Brillouin frequency shift values are the same.

5. The optical generation device of microwave signal, its characteristic is: the first optical amplifier is an optical amplifier capable of bidirectional optical amplification, and the second optical amplifier is an optical amplifier capable of unidirectional optical amplification.

Technical Field

The invention relates to a communication technology, an optical fiber laser technology and a microwave photon technology, in particular to an optical generation device of microwave signals.

Background

With the rapid development of internet technology and the rise of 5G technology nowadays, the development of modern communication technology towards high capacity, ultra-bandwidth and high speed is urgently needed. Based on the continuous expansion of the demand, the microwave, an important infinite transmission medium, is rapidly developed, and meanwhile, the optical fiber photon technology is also rapidly developed and rapidly combined with the microwave technology to develop a new microwave photon technology and rapidly become a research hotspot.

In order to optically generate high-frequency microwave signals, various methods have been proposed by domestic and foreign scientists, including direct modulation (also called internal modulation), external modulation frequency doubling, optical heterodyne, optoelectronic oscillator, multi-loop oscillator, and the like. The most important research methods include an external modulation method and optical heterodyne; the microwave generation scheme of the external modulation method mainly comprises the steps of modulating a modulator to generate a plurality of carrier optical sidebands, filtering the carrier optical sidebands by a photonic filter, and then performing beat frequency on two specific optical sidebands to obtain a frequency doubling signal. The optical heterodyne method is characterized in that two optical frequencies with a fixed frequency difference are coupled and transmitted through an optical fiber, and a photoelectric detector is used at a receiver end for beat frequency to obtain the difference of the output frequencies of the two lasers, wherein the change of the signal frequency of a laser source and the influence of noise on the stability and the purity of a beat frequency signal are great.

Disclosure of Invention

The invention provides an optical generation device of a microwave signal, which has a simple structure and low cost, and can realize the output of the microwave signal above 30GHz according to the Brillouin frequency shift of Brillouin optical fiber.

The invention adopts the following technical scheme for realizing the purpose:

an optical generation device for microwave signals comprises a narrow-linewidth adjustable laser (1), a first optical fiber coupler (2), a three-port 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 third optical fiber coupler (8), a second Brillouin optical fiber (9), a fourth optical fiber coupler (10) and a photoelectric detector (11).

In the optical microwave signal generating device, the connection relationship of each component is as follows: the output end of the narrow linewidth adjustable laser (1) is connected with an A1 port at an A end of a first optical fiber coupler (2), a B1 port at a B end of the first optical fiber coupler (2) is connected with a first port (31) of a three-port optical circulator (3), a second port (32) of the three-port optical circulator (3) is connected with one end of a first optical fiber amplifier (4), the other end of the first optical amplifier is connected between one ends of first Brillouin optical fibers (5), the other end of the first Brillouin optical fibers (5) is connected with a C1 port at a C end of a second optical fiber coupler (6), a D1 port at a D end of the second optical fiber coupler (6) is connected with a third port (33) of the three-port optical circulator (3), a D2 port at a D end of the second optical fiber coupler (6) is connected with an input end of a second optical amplifier (7), and the output end of the second optical amplifier is connected with an F1 port at an F end of a third optical fiber coupler (8), an E1 port at the E end of the third optical fiber coupler (8) is connected with the second Brillouin optical fiber (9), an F2 port at the F end of the third optical fiber coupler (8) is connected with an H1 port at the H end of the fourth optical fiber coupler (10), an H2 port at the H end of the fourth optical fiber coupler (10) is connected with a B2 port at the B end of the first optical fiber coupler (2), a G1 port at the G end of the fourth optical fiber coupler (10) is connected with an input port of the photoelectric detector (11), and an output port of the photoelectric detector can be connected to a spectrum analyzer.

The microwave signal optical generating device comprises a microwave signal optical generating process: laser output by the narrow linewidth tunable laser is split by a first optical fiber coupler (2), a part of the laser is output by a port B2 to be used as beat frequency light, a part of the laser is output by a port B1 to be used as Brillouin pump light (BP), the BP enters a first optical amplifier for amplification by a three-port optical circulator, the amplified BP is injected into one end of the first Brillouin optical fiber and generates Brillouin scattering therein, when the power of the amplified BP is large enough, the stimulated Brillouin scattering can be generated to generate first-order Stokes light which is transmitted reversely with the BP and shifts in frequency by Brillouin frequency (S1), S1 is injected into the other end of the first Brillouin optical fiber by the three-port optical circulator and a second optical fiber coupler and generates Brillouin scattering therein, when the power of S1 is large enough, the stimulated Brillouin scattering can be generated to generate second-order Stokes light which is transmitted reversely with S1 and shifts in frequency by Brillouin frequency (S2), s2 is output from a D2 port at the D end of the second optical fiber coupler, amplified by the second optical amplifier, and then injected into the second Brillouin optical fiber (9) through the third optical fiber coupler, when the amplified S2 has enough power, stimulated Brillouin scattering occurs, third-order Stokes light (S3) which is transmitted in reverse direction with S2 and undergoes Brillouin frequency shift in frequency is generated, S3 is transmitted to an H1 port at the H end of the fourth optical fiber coupler through an F2 port at the F end of the third optical fiber coupler, beat frequency occurs in the fourth optical fiber coupler with BP from a B2 port of the first optical fiber coupler, the beat frequency is output to a photoelectric detector (11) through a G1 port of the fourth optical fiber coupler, photoelectric conversion is achieved, and microwave signals can be observed on spectrum analysis.

Drawings

Fig. 1 is a schematic structural diagram of an optical microwave signal generating apparatus.

The reference numerals in the figures are to be interpreted: 1-narrow linewidth tunable laser, 2-first fiber coupler, A1-port of A end of first fiber coupler, B1-port of B end of first fiber coupler, B2-port of B end of first fiber coupler, 3-three-port optical circulator, one port of 31-three-port optical circulator, two ports of 32-three-port optical circulator, three ports of 33-three-port optical circulator, 4-first optical amplifier, 5-first Brillouin optical fiber, 6-second fiber coupler, C1-port of C end of second fiber coupler, D1-port of D end of second fiber coupler, D2-port of D end of second fiber coupler, 7-second optical amplifier, 8-third fiber coupler, E1-port of E end of third fiber coupler, f1-the port at the F end of the third optical fiber coupler, F2-the port at the F end of the third optical fiber coupler, 9-the second Brillouin optical fiber, 10-the fourth optical fiber coupler, G1-the port at the G end of the fourth optical fiber coupler, H1-the port at the H end of the fourth optical fiber coupler, H2-the port at the H end of the fourth optical fiber coupler, and 11-the photodetector.

Detailed Description

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

An optical generation device for microwave signals comprises a narrow-linewidth adjustable laser (1), a first optical fiber coupler (2), a three-port 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 third optical fiber coupler (8), a second Brillouin optical fiber (9), a fourth optical fiber coupler (10) and a photoelectric detector (11); in the optical microwave signal generating device, the connection relationship of each component is as follows: the output end of the narrow linewidth adjustable laser (1) is connected with an A1 port at an A end of a first optical fiber coupler (2), a B1 port at a B end of the first optical fiber coupler (2) is connected with a first port (31) of a three-port optical circulator (3), a second port (32) of the three-port optical circulator (3) is connected with one end of a first optical fiber amplifier (4), the other end of the first optical amplifier is connected between one ends of first Brillouin optical fibers (5), the other end of the first Brillouin optical fibers (5) is connected with a C1 port at a C end of a second optical fiber coupler (6), a D1 port at a D end of the second optical fiber coupler (6) is connected with a third port (33) of the three-port optical circulator (3), a D2 port at a D end of the second optical fiber coupler (6) is connected with an input end of a second optical amplifier (7), and the output end of the second optical amplifier is connected with an F1 port at an F end of a third optical fiber coupler (8), an E1 port at the E end of the third optical fiber coupler (8) is connected with the second Brillouin optical fiber (9), an F2 port at the F end of the third optical fiber coupler (8) is connected with an H1 port at the H end of the fourth optical fiber coupler (10), an H2 port at the H end of the fourth optical fiber coupler (10) is connected with a B2 port at the B end of the first optical fiber coupler (2), a G1 port at the G end of the fourth optical fiber coupler (10) is connected with an input port of the photoelectric detector (11), and an output port of the photoelectric detector can be connected to a spectrum analyzer.

The microwave signal optical generating device comprises a microwave signal optical generating process: laser output by the narrow linewidth tunable laser is split by a first optical fiber coupler (2), a part of the laser is output by a port B2 to be used as beat frequency light, a part of the laser is output by a port B1 to be used as Brillouin pump light (BP), the BP enters a first optical amplifier for amplification by a three-port optical circulator, the amplified BP is injected into one end of the first Brillouin optical fiber and generates Brillouin scattering therein, when the power of the amplified BP is large enough, the stimulated Brillouin scattering can be generated to generate first-order Stokes light which is transmitted reversely with the BP and shifts in frequency by Brillouin frequency (S1), S1 is injected into the other end of the first Brillouin optical fiber by the three-port optical circulator and a second optical fiber coupler and generates Brillouin scattering therein, when the power of S1 is large enough, the stimulated Brillouin scattering can be generated to generate second-order Stokes light which is transmitted reversely with S1 and shifts in frequency by Brillouin frequency (S2), s2 is output from a D2 port at the D end of the second optical fiber coupler, amplified by the second optical amplifier, and then injected into the second Brillouin optical fiber (9) through the third optical fiber coupler, when the amplified S2 has enough power, stimulated Brillouin scattering occurs, third-order Stokes light (S3) which is transmitted in reverse direction with S2 and undergoes Brillouin frequency shift in frequency is generated, S3 is transmitted to an H1 port at the H end of the fourth optical fiber coupler through an F2 port at the F end of the third optical fiber coupler, beat frequency occurs in the fourth optical fiber coupler with BP from a B2 port of the first optical fiber coupler, the beat frequency is output to a photoelectric detector (11) through a G1 port of the fourth optical fiber coupler, photoelectric conversion is achieved, and microwave signals can be observed on spectrum analysis.

The narrow linewidth adjustable laser is a semiconductor laser with linewidth in C wave band, the linewidth is not higher than 1MHz, and the output wavelength and power of the narrow linewidth adjustable laser can be tuned.

The first optical amplifier and the second optical amplifier are respectively formed by connecting a 980nm pump laser, a 1550nm/980nm wavelength division multiplexer and a section of erbium-doped optical fiber or other linear gain optical fibers with a certain length. The first optical amplifier is designed for bidirectional optical amplification, and the second optical amplifier is designed for unidirectional optical amplification.

The first Brillouin optical fiber and the second Brillouin optical fiber are single-mode quartz optical fibers with the same Brillouin frequency shift value, and the lengths of the first Brillouin optical fiber and the second Brillouin optical fiber are both 20 km.

The photoelectric detector is a photoelectric detector with the bandwidth higher than 30 GHz.

While the invention has been described in detail with respect to its operation, it will be apparent to those skilled in the art that variations may be made in the details of the embodiments based on the teachings of the invention and that such variations are considered to be within the scope of the invention.