阅读说明：本技术 刻度因数稳定的高精度光纤陀螺仪 (High-precision optical fiber gyroscope with stable scale factor ) 是由 周宏泽 吕翀 吕钢 于 2020-05-18 设计创作，主要内容包括：本发明涉及光纤陀螺仪技术领域,公开了一种刻度因数稳定的高精度光纤陀螺仪,以达到稳定陀螺刻度因数的目的。该陀螺仪包括宽谱光源发生器、第二端口插有滤波片的三端光纤环形器、多功能光学芯片、光纤传感环、光电探测器及信号处理单元；宽谱光源发生器输出光信号至三端光纤环形器的第一端口,三端光纤环形器的第二端口与多功能光学芯片的输入端耦合,多功能光学芯片上集成起偏器、Y型分束器和相位调制器,Y型分束器的两个输出端口与光纤传感环的两个输入端口耦合,三端光线环形器的第三端口与光电探测器的输入端耦合,光电探测器输出端通过信号处理单元与多功能光学芯片的相位调制器电连接,信号处理单元输出角速度信号,该陀螺仪刻度因素稳定。(The invention relates to the technical field of optical fiber gyroscopes, and discloses a high-precision optical fiber gyroscope with stable scale factors, so as to achieve the purpose of stabilizing the scale factors of the gyroscope. The gyroscope comprises a broad spectrum light source generator, a three-terminal optical fiber circulator with a second port inserted with a filter, a multifunctional optical chip, an optical fiber sensing ring, a photoelectric detector and a signal processing unit; the wide-spectrum light source generator outputs light signals to a first port of the three-terminal optical fiber circulator, a second port of the three-terminal optical fiber circulator is coupled with an input end of a multifunctional optical chip, a polarizer, a Y-shaped beam splitter and a phase modulator are integrated on the multifunctional optical chip, two output ports of the Y-shaped beam splitter are coupled with two input ports of an optical fiber sensing ring, a third port of the three-terminal optical fiber circulator is coupled with an input end of a photoelectric detector, an output end of the photoelectric detector is electrically connected with the phase modulator of the multifunctional optical chip through a signal processing unit, the signal processing unit outputs angular velocity signals, and scale factors of the gyroscope are stable.)

1. A high-precision optical fiber gyroscope with stable scale factors is characterized in that,

the device comprises a broad spectrum light source generator, a three-terminal optical fiber circulator (4) with a second port (4-2) inserted with a filter (4-4), a multifunctional optical chip (5), an optical fiber sensing ring (6), a photoelectric detector (7) and a signal processing unit (8);

the broad spectrum light source generator outputs light signals to a first port (4-1) of a three-terminal optical fiber circulator (4),

the second port (4-2) of the three-terminal optical fiber circulator (4) is coupled with the input end of the multifunctional optical chip (5),

a polarizer, a Y-shaped beam splitter and a phase modulator are integrated on the multifunctional optical chip (5),

two output ports of the Y-shaped beam splitter are coupled with two input ports of the optical fiber sensing ring (6),

the third port (4-3) of the three-terminal optical fiber circulator is coupled with the input end of a photoelectric detector (7),

the output end of the photoelectric detector (7) is connected with the signal processing unit (8), the modulation and feedback superposition output end of the signal processing unit (8) is electrically connected with the phase modulator of the multifunctional optical chip (5), and meanwhile, the signal processing unit (8) outputs an angular velocity signal.

2. The scale-factor-stabilized high-precision optical fiber gyroscope according to claim 1, wherein the broad-spectrum light source generator comprises a pump laser (1), a wavelength division multiplexing coupler (2) and an active fiber (3) which are coupled in sequence, and the optical signal is output from the wavelength division multiplexing coupler (2) to the first port (4-1) of the three-port fiber circulator (4).

3. The high-precision optical fiber gyroscope with stable scale factors as claimed in claim 2, wherein the tail end of the active optical fiber (3) is provided with a Faraday mirror or a common mirror.

4. The scale-factor-stabilized high-precision optical fiber gyroscope according to claim 1, wherein the broad-spectrum light source generator comprises a pump laser (1), a wavelength division multiplexing coupler (2) and an active fiber (3) which are coupled in sequence, and the optical signal is output from the active fiber (3) to a first port (4-1) of a three-port fiber circulator (4).

5. The high-precision optical fiber gyroscope with stable scale factors as claimed in claim 4, wherein the wavelength division multiplexing coupler (2) is provided with a Faraday mirror or a normal mirror at one end.

6. High-precision fiber optic gyroscope with scale-factor stabilization according to claim 1, characterized in that the second port (4-2) of the three-port fiber optic circulator (4) is coupled to the input of the multifunctional optical chip (5) by means of a polarization-maintaining fiber.

7. High-precision optical fiber gyro with stable scale factors according to claim 1, characterized in that the three-terminal fiber circulator (4) with the filter (4-4) inserted in the second port (4-2) is replaced by a separate circulator plus a separate filter connected between the separate circulator second port (4-2) and the multifunctional optical chip (5).

8. A high-precision optical fiber gyroscope with stable scale factors as claimed in claim 1, characterized in that the three-terminal fiber circulator (4) with the filter (4-4) inserted in the second port (4-2) is replaced by an isolator, a coupler and a filter, the isolator is connected between the broad-spectrum light source generator and the coupler, the filter is connected between the first output port of the coupler and the multifunctional chip, and the second output port of the coupler is coupled to the input of the photodetector (7).

Technical Field

The invention relates to the technical field of optical fiber gyroscopes, and particularly discloses a high-precision optical fiber gyroscope with stable scale factors.

Background

A conventional high-precision fiber-optic gyroscope structure is shown in fig. 3 and 4. Fig. 3 shows a backward pumping mode, in fig. 3, the light emitted from the pump laser 10 is excited by the wavelength division multiplexing coupler 20 to emit amplified spontaneous emission ASE (the tail end of the active fiber 30 may contain a faraday mirror or a common mirror); fig. 4 shows a forward pumping mode, in fig. 4, the light emitted from the pump laser 10 is excited by the wavelength division multiplexing WDM coupler 20 to emit amplified spontaneous emission ASE light from the active fiber 30 (one end of the wavelength division multiplexing coupler 20 includes a faraday mirror or a normal mirror 20-1); in fig. 3 or 4, the ASE light emitted from the active optical fiber 30 passes through the isolator 90 and the filter 100, and is divided into two by the coupler 110, wherein one beam enters the input end of the multifunctional lithium niobate integrated optical chip 50, the chip 50 is integrated with a polarizer, a Y-type beam splitter and a phase modulator, the Y-type beam splitter in the chip 50 divides the beam into two and outputs the two, and the upper beam passes through the optical fiber sensing ring 60 clockwise and then returns to the chip 50; the lower beam passes through the optical fiber sensing ring 60 in the counterclockwise direction and then returns to the chip 50; the two beams of clockwise light and anticlockwise light are synthesized by a Y-shaped beam splitter in the chip 50 to form interference, the interference is transmitted to the coupler 110 through the input end of the chip 50 to divide the light into two beams, one beam of the interference is converted into an electric signal by the photoelectric detector 70, the electric signal is fed back to the phase modulator in the chip 80 through the signal processing unit 80, and meanwhile, an angular velocity signal of the gyroscope relative to an inertial reference system is output.

Since the scale factor of the fiber-optic gyroscope is closely related to the average wavelength of the optical signal receiving end, the gyroscope needs to obtain a stable scale factor under a wide temperature condition, and thus the filter 100 plays a role in stabilizing the average wavelength of the light source. However, it is noted that what is needed to obtain a stable scale factor of the fiber-optic gyroscope is to stabilize the average wavelength of the light at the receiving end of the optical signal, rather than the average wavelength of the light at the output end of the light source, so that the conventional method for stabilizing the wavelength of the light source by using the filter 100 to achieve the stabilization of the average wavelength of the optical signal at the receiving end has a significant drawback; and the ASE light loses 3/4 light energy as it passes through coupler 110 a second time. In order to overcome the problems, the invention aims to provide the high-precision optical fiber gyroscope which can accurately control the optical average wavelength of the optical signal receiving end, thereby achieving the purpose of stabilizing the scale factor of the gyroscope, greatly reducing the loss of optical energy and effectively improving the signal-to-noise ratio of the gyroscope.

Disclosure of Invention

The invention aims to solve the problem that the average wavelength of light at a receiving end of a high-precision optical fiber gyroscope in a wide working temperature range is unstable and thus scale factors are unstable in the prior art, and provides the high-precision optical fiber gyroscope which can stabilize the average wavelength of light at the receiving end, namely the scale factors, and effectively improve the signal-to-noise ratio of the gyroscope.

The invention adopts the following specific technical scheme: a high-precision optical fiber gyroscope with stable scale factors comprises a broad spectrum light source generator, a three-end optical fiber circulator, a multifunctional optical chip, an optical fiber sensing ring, a photoelectric detector and a signal processing unit, wherein a filter is inserted into a second port of the three-end optical fiber circulator; the wide-spectrum light source generator outputs light signals to a first port of the three-terminal optical fiber circulator, a second port of the three-terminal optical fiber circulator is coupled with an input end of a multifunctional optical chip, a polarizer, a Y-shaped beam splitter and a phase modulator are integrated on the multifunctional optical chip, two output ports of the Y-shaped beam splitter are coupled with two input ports of an optical fiber sensing ring, a third port of the three-terminal optical fiber circulator is coupled with an input end of a photoelectric detector, an output end of the photoelectric detector is electrically connected with the phase modulator of the multifunctional optical chip through a signal processing unit, and the signal processing unit outputs angular velocity signals.

According to the technical scheme, light emitted by a pump laser is transmitted by a broad spectrum light source generator to be self-amplified and radiated ASE light, the ASE light is input to a first port of a special three-terminal optical fiber circulator with a filter, the ASE light passes through a birefringence and Faraday element inside the three-terminal optical fiber circulator and then is output from a second port of the three-terminal optical fiber circulator through an internal filter, the light enters the input end of a multifunctional lithium niobate integrated optical chip, a polarizer, a Y-shaped beam splitter and a phase modulator are sequentially integrated on the chip from the input end to the output end, the Y-shaped beam splitter in the chip divides a light beam into two parts and outputs the two parts, and an upper light beam passes through an optical fiber sensing ring in the clockwise direction and then returns to the chip; the lower light beam passes through the optical fiber sensing ring in the counterclockwise direction and then returns to the chip; the two beams of clockwise light and anticlockwise light are synthesized by a Y-shaped beam splitter in the chip to form interference, the interference is returned to a second port of the special circulator through an input end of the chip, the light enters the second port of the special circulator and firstly passes through an internal filter, then passes through an internal Faraday element and a birefringent element, is output from a third port of the circulator, is changed into an electric signal by a photoelectric detector, is produced and fed back to a phase modulator in the chip through a signal processing unit, and simultaneously outputs an angular velocity signal of the gyroscope relative to an inertial reference system. Because the scale factor of the fiber-optic gyroscope is closely related to the average wavelength of the light source, the gyroscope needs to obtain a stable scale factor under a wide temperature condition, therefore, when the ASE light passes through the special circulator for the first time, the internal filter close to the second port of the circulator plays a role in stabilizing the average wavelength output by the light source, and when the ASE light returns from the chip to pass through the circulator for the second time, the internal filter close to the second port plays a role in reducing the change of the average wavelength caused by the change of the wavelength filtering characteristics of the chip and the fiber-optic ring along with the temperature change, namely playing a role in stabilizing the average wavelength output by the light source again. The ASE spectrum is shaped into a Gaussian spectrum through a circulator integrated with a filter for the second time, and the zero-offset stability of the gyroscope is effectively improved. And, because 3/4 energy is not lost through the coupler twice, the optical receiving power can be increased four times in theory by using the three-terminal optical fiber circulator. Therefore, the high-precision optical fiber gyroscope capable of accurately controlling the optical average wavelength of the optical signal receiving end can be provided, so that the purpose of stabilizing the scale factor of the gyroscope is achieved, and the signal-to-noise ratio is improved.

Further, the broad spectrum light source generator comprises a pump laser, a wavelength division multiplexing coupler and an active fiber which are coupled in sequence, and the optical signal is output to a first port of the three-terminal fiber circulator from the wavelength division multiplexing coupler.

Furthermore, a Faraday reflector or a common reflector is arranged at the tail end of the active optical fiber. The Faraday reflector or the common reflector reflects the light at the starting position, and the output efficiency of the ASE light is improved.

Further, the broad spectrum light source generator comprises a pump laser, a wavelength division multiplexing coupler and an active optical fiber which are coupled in sequence, and the optical signal is output to the first port of the three-terminal optical fiber circulator from the active optical fiber.

Furthermore, a Faraday reflector or a common reflector is arranged at the free end of the wavelength division multiplexing coupler. The Faraday reflector or the common reflector reflects the light at the starting position, and the output efficiency of the ASE light is improved.

Furthermore, the second port of the three-terminal optical fiber circulator is coupled with the input end of the multifunctional optical chip through a polarization maintaining optical fiber. And the polarization-maintaining optical fiber is adopted, so that the influence of polarization-dependent loss of each part of the gyroscope is reduced.

Furthermore, the three-terminal optical fiber circulator with the filter plate inserted in the second port is replaced by an independent circulator and an independent filter, and the independent filter is connected between the second port of the independent circulator and the multifunctional optical chip.

Furthermore, the three-terminal optical fiber ring with the second port inserted with the filter is replaced by an isolator, a coupler and a filter, the isolator is connected between the wide-spectrum light source generator and the coupler, the filter is connected between the first output port of the coupler and the multifunctional chip, and the second output port of the coupler is coupled with the input end of the photoelectric detector.

The invention has the beneficial effects that: because the light beam passes through the three-terminal optical fiber circulator integrated with the filter twice, the change of the spectral distribution of the optical signal receiving end along with the temperature is effectively reduced, the scale factor of the gyroscope is stabilized, the spectrum is shaped into a Gaussian spectrum, the zero-offset stability of the gyroscope is provided, the optical receiving power is increased, and the signal-to-noise ratio of the gyroscope is improved.

Drawings

FIG. 1 is a schematic structural diagram of a high-precision optical fiber gyroscope with a stable scale factor according to the first embodiment;

FIG. 2 is a schematic diagram of a high-precision optical fiber gyroscope with a stable scale factor according to the second embodiment;

fig. 3 and 4 are two conventional high-precision optical fiber gyroscopes.

In the figure, 1, a pump laser; 2. a wavelength division multiplexing coupler; 3. an active optical fiber; 4. a three-terminal optical fiber circulator; 4-1, a first port; 4-2, a second port; 4-3, a third port; 4-4, a filter plate; 5. a multifunctional optical chip; 6. an optical fiber sensing ring; 7. a photodetector; 8. a signal processing unit; 10. a pump laser; 20. a wavelength division multiplexing coupler; 20-1, a reflector; 30. an active optical fiber; 50. a chip; 60. an optical fiber sensing ring; 70. a photodetector; 80. a signal processing unit; 90. an isolator; 100. a filter; 110. a coupler.

Detailed Description