CN108801237B - Method and device for inhibiting Kerr effect noise of double-path closed-loop resonant optical gyroscope based on second harmonic subtraction - Google Patents
Method and device for inhibiting Kerr effect noise of double-path closed-loop resonant optical gyroscope based on second harmonic subtraction Download PDFInfo
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- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
- G01C19/58—Turn-sensitive devices without moving masses
- G01C19/64—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams
- G01C19/66—Ring laser gyrometers
- G01C19/661—Ring laser gyrometers details
- G01C19/662—Ring laser gyrometers details signal readout; dither compensators
- G01C19/664—Ring laser gyrometers details signal readout; dither compensators means for removing the dither signal
Abstract
The invention discloses a method and a device for inhibiting Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technology. A device for realizing the method comprises a tunable semiconductor laser, an isolator, a light splitting coupler, a first phase modulator, a second phase modulator, a first signal source, a second signal source, a third phase modulator, a fourth phase modulator, a cavity entrance coupler, an optical ring resonator, a cavity exit coupler, a first photoelectric detector, a first phase-locked amplifier, a frequency servo circuit, a third phase-locked amplifier, a second photoelectric detector, a second phase-locked amplifier, a frequency shift module, a fourth phase-locked amplifier and a harmonic subtraction compensation module. The invention can effectively reduce the gyro output error caused by Kerr effect, the real-time compensation can be realized by adopting the harmonic subtraction algorithm, the algorithm is only realized in codes, and no additional optical devices or electrical modules are needed, the structure is simple, and the system miniaturization is facilitated.
Description
Technical Field
The invention relates to the technical field of optical sensing and signal detection, in particular to a method and a device for inhibiting Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technology.
Background
Resonant Optical Gyros (ROGs) are inertial sensors that use the optical Sagnac effect to enable detection of rotation.
Kerr effect noise is an error introduced by changes in the refractive index of the optic due to changes in light intensity. The tunable narrow linewidth semiconductor laser is an important light source for realizing the miniaturization of the resonant optical gyro system. In a signal detection system of a resonant optical gyroscope using a semiconductor laser as a light source, a method of tuning the injection current of the semiconductor laser is usually adopted to lock the frequency of emergent light at the resonant frequency of an optical ring resonator, so as to realize closed-loop locking of a system loop. However, when the injection current of the semiconductor laser changes, the output light power of the laser simultaneously undergoes a certain accompanying intensity modulation, and the accompanying intensity modulation effect causes Kerr effect noise, thereby generating an error of the gyro output. On the other hand, Kerr effect noise is also introduced by optical power fluctuation caused by unstable performance of each element in the gyro system. The method for inhibiting Kerr effect noise has important significance for improving the performance of the resonant optical gyroscope.
Disclosure of Invention
The invention provides a method and a device for inhibiting Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technology, aiming at the problem of Kerr effect noise induced by optical power fluctuation caused by intensity modulation of a semiconductor laser and instability of other components in the conventional double-path closed-loop resonant optical gyroscope system.
A method for suppressing Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technology comprises the following steps:
1) the Kerr effect is caused by the Sagnac effect and by integrating the propagation coefficient of the disturbance produced by the Kerr effectError omega ofKCan be expressed as:
in the formula uCW＝kc0(1-ɑc0)(1-ɑPM1)(1-ɑPM3) Wherein k isc0And alphac0The coupling factor and the insertion loss, alpha, of the 50% coupler (3), respectivelyPM1And alphaPM3The insertion loss u of the first phase modulator (4) and the third phase modulator (8), respectivelyCCW＝kc0(1-ɑc0)(1-ɑPM2)(1-ɑPM4)，ɑPM2And alphaPM4The insertion loss, k, of the second phase modulator (5) and the fourth phase modulator (9), respectivelyc1And alphac1Coupling coefficient and insertion loss, k, of the cavity coupler (10), respectivelyc2And alphac2The coupling coefficient and insertion loss of the cavity-out coupler (12), αLIs the transmission loss of light in the optical cavity, FSR ═ c/(n)rL) is the free line width, nrIs the refractive index of the medium of the optical cavity, c is the speed of light in vacuum, ω is the central angular frequency of the output light of the laser, η is the impedance of the medium of the optical cavity, A is the area of the optical power receiving surface, n2Is the Kerr coefficient, I0Is the initial output intensity of the laser, Δ feIs the shift of the resonant point of the first locked loop, k, caused by environmental factorsfAnd kiFrequency and intensity modulation factor, f, of the semiconductor laserM_CWAnd fM_CCWIs the equivalent frequency modulated signal after passing through the phase modulator.
2) Obtaining secondary frequency signals V of first and second closed loops of gyroscope under sine wave phase modulation by applying light field superposition principled2_CW、Vd2_CCWExpression (c):
in the formula, Jn(M) is a Bessel function, M is a phase modulation factor, I0Is the initial output intensity of the laser, Δ feIs the shift of the resonance point of the first locked loop, k, caused by environmental factorsfAnd kiAre respectively the frequency and intensity modulation factor, h 'of the semiconductor laser'n、hnThe amplitude characteristics of the resonant cavity transfer functions of the first and second loops respectively,
is the phase characteristic of the transfer function of the first and second loop resonators, P1、P2Are the conversion coefficients of the photodetectors (17) and (13), respectively, AD1、AD2The gain of the lock-in amplifiers (19) and (16), respectively.
Defining a normalized frequency-doubled signal, wherein the expression is as follows:
in step (1)
And
can be expressed as:
k1、k2the conversion coefficient between the gyro output error caused by the Kerr effect and the normalized frequency doubling difference is obtained, so that the error caused by the Kerr effect is represented by two paths of normalized frequency doubling difference signals:
k1and k2Approximately equal, and therefore, the final gyro output is: omegaF'＝ΩF-k1·(PCW-PCCW)，ΩFThe Kerr error is included for the initial gyro output.
Wherein k is1、k2Calculating by a theoretically derived expression; or the k is obtained by testing the actual relation between the final gyro output and the normalized frequency doubling difference and linearly fitting the relation of the two1And k is2；k1、k2The theoretically derived expression is:
the invention also discloses a device for suppressing Kerr effect noise of the resonant optical gyroscope based on a second harmonic subtraction technology, which comprises a tunable semiconductor laser, an isolator, a 50% coupler, a first phase modulator, a second phase modulator, a first signal source, a second signal source, a third phase modulator, a fourth phase modulator, a cavity-in coupler, an optical annular resonant cavity, a cavity-out coupler, a first photoelectric detector, a first phase-locked amplifier, a frequency servo loop, a third phase-locked amplifier, a second photoelectric detector, a second phase-locked amplifier, a fourth phase-locked amplifier, a frequency shift module and a harmonic subtraction algorithm module, wherein the cavity-in coupler and the cavity-out coupler are 95% couplers; the tunable semiconductor laser is connected with an isolator, the isolator is connected with a 50% coupler, two paths of outputs of the 50% coupler are respectively connected with a first phase modulator and a second phase modulator, the first phase modulator is connected with a third phase modulator, the second phase modulator is connected with a fourth phase modulator, output light of the third phase modulator and output light of the fourth phase modulator enter an optical ring-shaped resonant cavity through a cavity-entering coupler, two paths of light of the optical ring-shaped resonant cavity are output through a cavity-exiting coupler, output ends of the cavity-exiting coupler are respectively connected with a first path of photoelectric detector and a second path of photoelectric detector, output ends of the first path of photoelectric detector are respectively connected with a first path of phase-locked amplifier and a third path of phase-locked amplifier, the output end of the first path of phase-locked amplifier is connected with a frequency servo loop, and the output end of the frequency servo loop is connected with a tuning end of the tunable semiconductor laser, forming a frequency servo loop, wherein the output of a third phase-locked amplifier is connected with a harmonic subtraction algorithm module, the output of a second photoelectric detector is connected with a second phase-locked amplifier and a fourth phase-locked amplifier, the output of the second phase-locked amplifier is connected with a frequency shift module, the output of the frequency shift module is connected with a third phase modulator to form a second servo loop, and the output end of the frequency shift module is also connected with the harmonic subtraction module to provide an initial gyroscope output signal; the first path of signal source is used as a modulation signal of a first phase modulator; the second signal source is used as the modulation signal of the second phase modulator.
Compared with the prior art, the invention has the following beneficial effects:
1) the invention can effectively inhibit Kerr effect noise introduced in the system due to light intensity change, and improve the precision and stability of gyroscope output.
2) The invention adopts the method of respectively detecting the secondary frequency demodulation output signals of the two loops to represent the light intensity of the gyroscope cavity, can realize real-time monitoring, has simple method, does not need to add additional optical and electrical devices, and is beneficial to the miniaturization of the system.
3) According to the invention, the relation between the optical power difference and Kerr effect noise is obtained by linearly fitting the relation between the gyroscope output and two paths of normalized frequency doubling differences according to the actual measurement result, so that the conversion coefficient between the gyroscope output error caused by the Kerr effect and the normalized frequency doubling differences is obtained; meanwhile, by a linear fitting method, a weak Kerr effect error submerged in gyro output signal noise can be visually displayed along with the change of an optical power difference.
4) The harmonic subtraction algorithm is adopted, the secondary frequency demodulation output of the two loops and the primary frequency demodulation output of the first loop are used as the input of the harmonic subtraction algorithm module, real-time compensation can be achieved, the algorithm can achieve real-time compensation adjustment of relevant parameters only in codes, extra optical and electrical devices are not needed, the structure is simple, and system miniaturization is facilitated.
Drawings
FIG. 1 is a structural diagram of Kerr effect noise suppression of a resonant optical gyroscope based on a second harmonic subtraction technique;
in fig. 1: the tunable laser device comprises a tunable semiconductor laser (1), an isolator (2), a 50% coupler (3), a first phase modulator (4), a second phase modulator (5), a first path signal source (6), a second path signal source (7), a third phase modulator (8), a fourth phase modulator (9), a cavity-in coupler (10), an optical ring resonator (11), a cavity-out coupler (12), a first path photoelectric detector (13), a first path phase-locked amplifier (14), a frequency servo loop (15), a third path phase-locked amplifier (16), a second path photoelectric detector (17), a second path phase-locked amplifier (18), a fourth path phase-locked amplifier (19), a frequency shift module (20) and a harmonic subtraction algorithm module (21).
FIG. 2 is a graph of the relationship between the output of a gyroscope without harmonic subtraction and the normalized frequency-doubled difference.
FIG. 3 is a graph of gyro output by harmonic subtraction versus normalized second harmonic difference.
Detailed Description
The present invention will be described in detail below with reference to examples and drawings, but the present invention is not limited thereto.
As shown in fig. 1, the structure for suppressing Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technology includes a tunable semiconductor laser 1, an isolator 2, a 50% coupler 3, a first phase modulator 4, a second phase modulator 5, a first signal source 6, a second signal source 7, a third phase modulator 8, a fourth phase modulator 9, an input cavity coupler 10, an optical ring resonator 11, an output cavity coupler 12, a first photo detector 13, a first phase-locked amplifier 14, a frequency servo circuit 15, a third phase-locked amplifier 16, a second photo detector 17, a second phase-locked amplifier 18, a fourth phase-locked amplifier 19, a frequency shift module 20, and a harmonic subtraction algorithm module 21. The tunable semiconductor laser 1 is connected with an isolator 2, the isolator 2 is connected with a 50% coupler 3, two paths of outputs of the 50% coupler 3 are respectively connected with a first phase modulator 4 and a second phase modulator 5, the first phase modulator 4 is connected with a third phase modulator 8, the second phase modulator 5 is connected with a fourth phase modulator 9, output light of the third phase modulator 8 and the fourth phase modulator 9 enters an optical ring-shaped resonant cavity 11 through a 95% coupler 10, two paths of light of the optical ring-shaped resonant cavity 11 are output through a 95% coupler 12, output ends of the 95% coupler 12 are respectively connected with a first path of photoelectric detector 13 and a second path of photoelectric detector 17, output ends of the first path of photoelectric detector 13 are respectively connected with a first path of phase-locked amplifier 14 and a third path of phase-locked amplifier 16, output ends of the first path of phase-locked amplifier 14 are connected with a frequency servo circuit 15, the output of the frequency servo circuit 15 is connected with the tuning end of the tunable semiconductor laser 1 to form a frequency servo circuit, the output of the third phase-locked amplifier 16 is connected with a harmonic subtraction algorithm module 21, the output of the second photoelectric detector 17 is connected with the second phase-locked amplifier 18 and the fourth phase-locked amplifier 19, the output of the second phase-locked amplifier 18 is connected with a frequency shift module 20, the output of the frequency shift module 20 is connected with the third phase modulator 8 to form a second servo circuit, and the output end of the frequency shift module is also connected with the harmonic subtraction algorithm module 21 to provide an initial gyro output signal; the first path of signal source 6 is used as a modulation signal of the first phase modulator 4; the second signal source 7 is used as the modulation signal of the second phase modulator 5.
Laser emitted by the tunable semiconductor laser 1 is divided into two beams of light with equal optical power through the isolator 2 and the 50% coupler 3: a clockwise path and a counterclockwise path. The two paths of light respectively pass through the first phase modulator 4 and the third phase modulator 8 and the second phase modulator 5 and the fourth phase modulator 9 to enter the optical ring resonator 11. The counterclockwise laser passes through the optical ring resonator 11 and then is photoelectrically converted by the first photo detector 13, one of the counterclockwise laser passes through the first lock-in amplifier 14 for demodulation, the demodulated output passes through the frequency servo circuit 15 to control the frequency of the output light of the tunable miniaturized laser 1, the other part passes through the third lock-in amplifier 16 for second frequency demodulation, the second frequency demodulated output signal is finally used as the input signal of the harmonic subtraction algorithm module 21, the clockwise laser output passes through the second photo detector 17 for photoelectric conversion, one of the counterclockwise laser passes through the second lock-in amplifier 18 for demodulation, the demodulated output is connected to the third phase modulator 8 through the frequency shift module 20 to form the second servo circuit, the other part passes through the fourth lock-in amplifier 19 for second frequency demodulation, and the two demodulated outputs of the clockwise laser are used as the input signal of the other part of the harmonic subtraction algorithm module 21, and finally, the output of the harmonic subtraction algorithm module 21 is used as a gyro output signal.
The method for suppressing Kerr effect noise of the resonant optical gyroscope based on the second harmonic subtraction technology comprises the following steps:
the output light of the two optical paths is converted into an electric signal by a photoelectric detector and then demodulated by a primary frequency sinusoidal signal and a secondary frequency sinusoidal signal respectively. Wherein, the primary frequency demodulation signals are respectively used for the feedback of two closed loop circuits; and the second frequency demodulation signal is input to a harmonic subtraction algorithm module and is used for compensating gyro output fluctuation caused by optical power fluctuation in real time. It should be noted that, during the execution of the harmonic subtraction algorithm, the frequencies of the two paths of light are locked at respective resonant frequency points, and at this time, the second-order frequency signals of the two closed loops are in a linear relationship with the light intensity.
The specific treatment method comprises the following steps:
the method for suppressing Kerr effect noise of the resonant optical gyroscope based on the secondary frequency signal detection technology comprises the following steps:
1) kerr effect noise omega in double-path closed-loop resonant optical gyroscopeKCan be expressed as:
in the formula uCW＝kc0(1-ɑc0)(1-ɑPM1)(1-ɑPM3) Wherein k isc0And alphac0The coupling factor and the insertion loss, alpha, of the 50% coupler (3), respectivelyPM1And alphaPM3The insertion loss u of the first phase modulator (4) and the third phase modulator (8), respectivelyCCW＝kc0(1-ɑc0)(1-ɑPM2)(1-ɑPM4)，ɑPM2And alphaPM4The insertion loss, k, of the second phase modulator (5) and the fourth phase modulator (9), respectivelyc1And alphac1Coupling coefficient and insertion loss, k, of the cavity coupler (10), respectivelyc2And alphac2The coupling coefficient and insertion loss of the cavity-out coupler (12), αLIs the transmission loss of light in the optical cavity, FSR ═ c/(n)rL) is the free line width, nrIs the refractive index of the medium of the optical cavity, c is the speed of light in vacuum, ω is the central angular frequency of the output light of the laser, η is the impedance of the medium of the optical cavity, A is the area of the optical power receiving surface, n2Is the Kerr coefficient, I0Is the initial output intensity of the laser, Δ feIs the shift of the resonant point of the first locked loop, k, caused by environmental factorsfAnd kiFrequency and intensity modulation factor, f, of the semiconductor laserM_CWAnd fM_CCWIs the equivalent frequency modulated signal after passing through the phase modulator.
2) Obtaining secondary frequency signals V of first and second closed loops of gyroscope under sine wave phase modulation by applying light field superposition principled2_CW、Vd2_CCWThe expression of (a) is:
in the formula, Jn(M) is a Bessel function, M is a phase modulation factor, I0Is the initial output intensity of the laser, Δ feIs the shift of the resonance point of the first locked loop, k, caused by environmental factorsfAnd kiAre respectively the frequency and intensity modulation factor, h 'of the semiconductor laser'n、hnThe amplitude characteristics of the resonant cavity transfer functions of the first and second loops respectively,
is the phase characteristic of the transfer function of the first and second loop resonators, P1、P2Are the conversion coefficients of the photodetectors (17) and (13), respectively, AD1、AD2The gain of the lock-in amplifiers (19) and (16), respectively.
Defining a normalized frequency-doubled signal, wherein the expression is as follows:
in step (1)
And
can be expressed as:
k1、k2the conversion coefficient between the gyro output error caused by the Kerr effect and the normalized frequency doubling difference is obtained, so that the error caused by the Kerr effect is represented by two paths of normalized frequency doubling difference signals:
k1and k2Approximately equal, and therefore, the final gyro output is: omegaF'＝ΩF-k1·(PCW-PCCW)，ΩFThe Kerr error is included for the initial gyro output.
Wherein k is1、k2Calculating by a theoretically derived expression; or the final gyro output and the normalized second harmonic difference are tested to obtain the actual relation, and the relation between the final gyro output and the normalized second harmonic difference is linearly fittedIs obtained to k1And k is2；k1、k2The theoretically derived expression is:
FIG. 2 shows the difference between the initial two optical powers of 7.54 × 10-7And in W, the relationship between the gyro output and the normalized second harmonic difference. The gyro output in the figure is the initial gyro output obtained after demodulation of the frequency shift module (20), and the normalized frequency doubling difference is the result obtained after demodulation of the third phase-locked amplifier (16) and the fourth phase-locked amplifier (19) respectively. In the figure, the solid lines are experimental data, and the solid lines are fitting results according to experimental data points. Because the output error of the gyroscope caused by the Kerr effect is small, the conversion coefficient between the output error of the gyroscope caused by the Kerr effect and the normalized second harmonic difference can be obtained by performing linear fitting on the experimental test result.
FIG. 3 shows the difference between the initial two optical powers of 7.54 × 10-7And in W, the relationship between the gyro output after harmonic subtraction and the normalized second harmonic difference is adopted, the gyro output in the figure is the gyro output obtained after the harmonic subtraction module (21), and the normalized second harmonic difference is the result obtained after the third lock-in amplifier (16) and the fourth lock-in amplifier (19) are respectively demodulated. The solid lines are experimental data and the solid lines are fitting results based on experimental data points.
Comparing the results of fig. 2 and fig. 3, it can be seen that the output of the gyro is significantly reduced by the normalized frequency doubling difference after the harmonic subtraction technique is employed, indicating that the Kerr effect error caused by the fluctuation of the optical power difference is effectively suppressed.
Claims (3)
1. A method for suppressing Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technology is characterized by comprising the following steps:
1) error omega caused by Kerr effect based on Sagnac effect and integral of disturbance propagation coefficient generated by Kerr effectKCan be expressed as:
in the formula uCW＝kc0(1-ɑc0)(1-ɑPM1)(1-ɑPM3) Wherein k isc0And alphac0The coupling factor and the insertion loss, alpha, of the 50% coupler (3), respectivelyPM1And alphaPM3The insertion loss u of the first phase modulator (4) and the third phase modulator (8), respectivelyCCW＝kc0(1-ɑc0)(1-ɑPM2)(1-ɑPM4)，ɑPM2And alphaPM4The insertion loss, k, of the second phase modulator (5) and the fourth phase modulator (9), respectivelyc1And alphac1Coupling coefficient and insertion loss, k, of the cavity coupler (10), respectivelyc2And alphac2The coupling coefficient and insertion loss of the cavity-out coupler (12), αLIs the transmission loss of light in the optical cavity, FSR ═ c/(n)rL) is the free line width, nrIs the refractive index of the medium of the optical cavity, c is the speed of light in vacuum, ω is the central angular frequency of the output light of the laser, η is the impedance of the medium of the optical cavity, A is the area of the optical power receiving surface, n2Is the Kerr coefficient, I0Is the initial output intensity of the laser, Δ feIs the shift of the resonant point of the first locked loop, k, caused by environmental factorsfAnd kiFrequency and intensity modulation factor, f, of the semiconductor laserM_CWAnd fM_CCWIs the equivalent frequency modulated signal after passing through the phase modulator;
2) obtaining secondary frequency signals V of first and second closed loops of gyroscope under sine wave phase modulation by applying light field superposition principled2_CW、Vd2_CCWExpression (c):
in the formula, Jn(M) is a Bessel function, M is a phase modulation factor, h'n、hnAre respectively asThe amplitude characteristics of the resonant cavity transfer functions of the first and second loops,
phase characteristics, P, of transfer functions of the first and second resonant cavities, respectively1、P2Respectively the conversion coefficients of the second path of photoelectric detector (17) and the first path of photoelectric detector (13), AD1、AD2The gains of a fourth lock-in amplifier (19) and a third lock-in amplifier (16) respectively;
defining a normalized frequency-doubled signal, wherein the expression is as follows:
in step (1)
And
can be expressed as:
k1、k2the conversion coefficient between the gyro output error caused by the Kerr effect and the normalized frequency doubling difference is obtained, so that the error caused by the Kerr effect is represented by two paths of normalized frequency doubling difference signals:
k1and k2Approximately equal, and therefore, the final gyro output is: omegaF'＝ΩF-k1·(PCW-PCCW)，ΩFKerr error is included for the initial gyro output;
wherein k is1、k2Calculating by a theoretically derived expression; or the k is obtained by testing the actual relation between the final gyro output and the normalized frequency doubling difference and linearly fitting the relation of the two1And k is2；k1、k2The theoretically derived expression is:
2. a device for suppressing Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technique, the tunable laser is characterized by comprising a tunable semiconductor laser (1), an isolator (2), a 50% coupler (3), a first phase modulator (4), a second phase modulator (5), a first path signal source (6), a second path signal source (7), a third phase modulator (8), a fourth phase modulator (9), an in-cavity coupler (10), an optical ring resonator (11), an out-cavity coupler (12), a first path photoelectric detector (13), a first path phase-locked amplifier (14), a frequency servo circuit (15), a third path phase-locked amplifier (16), a second path photoelectric detector (17), a second path phase-locked amplifier (18), a fourth path phase-locked amplifier (19), a frequency shift module (20) and a harmonic subtraction algorithm module (21); the tunable semiconductor laser (1) is connected with an isolator (2), the isolator (2) is connected with a 50% coupler (3), two paths of outputs of the 50% coupler (3) are respectively connected with a first phase modulator (4) and a second phase modulator (5), the first phase modulator (4) is connected with a third phase modulator (8), the second phase modulator (5) is connected with a fourth phase modulator (9), output light of the third phase modulator (8) and output light of the fourth phase modulator (9) enter an optical ring-shaped resonant cavity (11) through an cavity-in coupler (10), two paths of light of the optical ring-shaped resonant cavity (11) are output through a cavity-out coupler (12), the output end of the cavity-out coupler (12) is respectively connected with a first path of photoelectric detector (13) and a second path of photoelectric detector (17), the output end of the first path of photoelectric detector (13) is respectively connected with a first path of phase-locked amplifier (14), The output of the third phase-locked amplifier (16) is connected with a frequency servo loop (15), the output of the frequency servo loop (15) is connected with a tuning end of the tunable semiconductor laser (1) to form a frequency servo loop, the output of the third phase-locked amplifier (16) is connected with a harmonic subtraction algorithm module (21), the output of the second photoelectric detector (17) is connected with the output of the second phase-locked amplifier (18) and the output of the fourth phase-locked amplifier (19), the output of the second phase-locked amplifier (18) is connected with a frequency shift module (20), the output of the frequency shift module (20) is connected with a third phase modulator (8) to form a second servo loop, and the output end of the frequency shift module is also connected with the harmonic subtraction algorithm module (21) to provide an initial gyro output signal; the first path of signal source (6) is used as a modulation signal of the first phase modulator (4); the second signal source (7) is used as a modulation signal of the second phase modulator (5).
3. The apparatus for suppressing Kerr effect noise of a resonant optical gyroscope based on a second harmonic subtraction technology according to claim 2, wherein the third lock-in amplifier (16) and the fourth lock-in amplifier (19) are used for demodulating a second frequency signal in real time, so as to detect optical power in the two loops, and further characterize Kerr error in the system by using a difference between two normalized frequency-doubled signals.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101464151A (en) * | 2009-01-05 | 2009-06-24 | 浙江大学 | Detection apparatus and method for miniature resonance type optical gyroscope with double-signal combined modulation |
| CN102331258A (en) * | 2011-07-12 | 2012-01-25 | 浙江大学 | Two-path loop-locked resonant mode optical gyro |
| CN102353373A (en) * | 2011-07-12 | 2012-02-15 | 浙江大学 | Double-closed loop locking technology-based resonant optical gyro |
| CN103968821A (en) * | 2014-05-19 | 2014-08-06 | 中北大学 | Two-way resonant optical gyroscope |
| CN105973220A (en) * | 2016-05-05 | 2016-09-28 | 浙江大学 | Secondary frequency signal detection technology-based resonant fiber optic gyroscope light source intensity modulation noise inhibition method and device |
-
2018
- 2018-06-08 CN CN201810589519.6A patent/CN108801237B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101464151A (en) * | 2009-01-05 | 2009-06-24 | 浙江大学 | Detection apparatus and method for miniature resonance type optical gyroscope with double-signal combined modulation |
| CN102331258A (en) * | 2011-07-12 | 2012-01-25 | 浙江大学 | Two-path loop-locked resonant mode optical gyro |
| CN102353373A (en) * | 2011-07-12 | 2012-02-15 | 浙江大学 | Double-closed loop locking technology-based resonant optical gyro |
| CN103968821A (en) * | 2014-05-19 | 2014-08-06 | 中北大学 | Two-way resonant optical gyroscope |
| CN105973220A (en) * | 2016-05-05 | 2016-09-28 | 浙江大学 | Secondary frequency signal detection technology-based resonant fiber optic gyroscope light source intensity modulation noise inhibition method and device |
Non-Patent Citations (8)
| Title |
|---|
| Analysis of Kerr effect in resonator fiber optic gyros with triangular wave phase modulation;D.Ying等;《APPLIED OPTICS》;20100120;第49卷(第3期);529-535 * |
| Closed-loop resonant fiber optic gyro with an improved digital serrodyne modulation;Zhonghe Jin等;《ResearchGate》;20131130;26578-26588 * |
| Kerr effect in an optical passive ring-resonator gyro;KATSUMI IWATSUKI等;《JOUNAL OF LIGHTWAVE TECHNOLOGY》;19860630;第LT-4卷(第6期);645-651 * |
| Test and Analysis of the Optical Kerr-Effect in Resonant Micro-Optic Gyros;Xuehui Li等;《IEEE Photonics Journal》;20141031;第6卷(第5期);1-8 * |
| The Passive Resonator Fiber Optic Gyro and Comparison to the Interferometer Fiber Gyro;R. Carroll等;《Proceedings of the SPIE,Fiber Optic Gyros：10th Anniversary Conference》;19871231;第719卷;169-177 * |
| 谐振式光纤陀螺调相检测分析;张旭琳等;《中国激光》;20051130;第32卷(第11期);1529-1533 * |
| 谐振式微光学陀螺中光学Kerr噪声研究;李学辉;《中国优秀硕士学位论文全文数据库信息科技II辑》;20150515(第5期);I140-304 * |
| 谐振式空心光子带隙光纤陀螺中的光克尔效应;于秀娟等;《中国激光》;20080331;第35卷(第3期);430-435 * |
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