CN104236537B - Light source intensity noise based on intensity modulator suppresses digital double closed-loop method - Google Patents
Light source intensity noise based on intensity modulator suppresses digital double closed-loop method Download PDFInfo
- Publication number
- CN104236537B CN104236537B CN201410462716.3A CN201410462716A CN104236537B CN 104236537 B CN104236537 B CN 104236537B CN 201410462716 A CN201410462716 A CN 201410462716A CN 104236537 B CN104236537 B CN 104236537B
- Authority
- CN
- China
- Prior art keywords
- intensity
- intensity modulator
- modulator
- noise
- bias voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- 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
- G01C19/72—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams with counter-rotating light beams in a passive ring, e.g. fibre laser gyrometers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C25/00—Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Optics & Photonics (AREA)
- Electromagnetism (AREA)
- Power Engineering (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Gyroscopes (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
The present invention is that a kind of light source intensity noise based on intensity modulator suppresses digital double closed-loop method, belongs to fiber-optics gyroscope field.This method carries out the suppression of intensity noise and the stabilization of intensity modulator operating point using digital double closed-loop loop；When intensity noise suppresses, the light intensity signal that photodetector is exported is pre-processed, digitized, is filtered and phase compensation after, then simulated feed back to intensity modulator；During the offset operation point of strength of stability modulator, bias voltage when obtaining intensity modulator maximum output luminous power point and minimum Output optical power point by scanning bias voltage, the bias voltage of operating point is obtained using mean power method, and intensity modulator is fed back to by the output voltage acquisition bias voltage difference for gathering photodetector in real time.It is bad that the present invention solves closed-loop precision, the problem of noise suppression effect is poor, improves the signal to noise ratio of optical fibre gyro light source, the offset operation point of intensity modulator is no longer drifted about, working stability.
Description
Technical field
The invention belongs to fiber-optics gyroscope field, and in particular to optical fibre gyro is made an uproar with the intensity of superfluorescent fiber sources
The suppression technology of sound, and in particular to a kind of light source intensity noise based on intensity modulator suppresses digital double closed-loop method.
Background technology
Optical fibre gyro is as a kind of extremely rapid new inertia angular-rate sensor of development, in increasing field
Inertia device is selected as main, the main direction of studying as inertia device of future generation.Optical fibre gyro except with movement-less part,
Outside advantage without error caused by acceleration, an important difference of itself and traditional electro-mechanical gyro is to there is larger optics to make an uproar
Sound, and wherein a kind of main noise is the noise that wide spectrum light source is brought.
The noise of optical fibre gyro directly affects the performance indications such as the random walk coefficient of optical fibre gyro, zero inclined unstability,
And the minimum detection sensitivity of optical fibre gyro is directly decide, so the noise progress suppression to optical fibre gyro is extremely important
's.
The noise of the wide spectrum light source of optical fibre gyro mainly includes thermal noise, shot noise and intensity noise.Intensity noise is
Due to caused by the beat frequency of wide spectrum light source, be due to wide spectrum light source various Fourier (Fourier) component between beat frequency draw
The additional noise risen, its size increases with the increase of the light intensity of light source.The size and light source output power of intensity noise
Size be directly proportional, when light source power exceed certain value when, intensity noise just exceed shot noise and thermal noise, at this moment, noise
Than that no longer will be improved with the increase of luminous power, but level off to a saturation value, intensity noise just turns into source noise
Topmost part.
Suppress the intensity noise in optical fibre gyro light source, the signal to noise ratio of optical fibre gyro can be effectively improved, so as to improve
The accuracy of detection of optical fibre gyro, to realizing that the practical application of optical fibre gyro is significant.At present, optical fibre gyro intensity noise
Suppression technology method mainly has：Intensity noise cancellation techniques scheme, using high speed intensity modulator scheme and subtract each other compensation technique
Scheme etc..
In these methods, it is to apply a kind of more methods in recent years using the scheme of high speed intensity modulator, this
The structure for the device that a kind of intensity noise that the method for kind is provided suppresses is as shown in figure 1, the restraining device mainly includes：Light light
Source, intensity modulator, coupler, the servo controller in photo-detector and high broadband.The operation principle of the restraining device is as follows：It is high
The intensity modulator of speed is placed between optical fiber source and coupler, and the optical signal sent from light light source reaches intensity modulator,
Intensity modulator is modulated to the optical signal received；Intensity modulator is by the light output through ovennodulation to coupler, coupling
A part of light that device is separated is detected by photo-detector, and photo-detector sample obtaining current signal to the optical signal received
And be converted to voltage signal.Voltage signal is output on the servo controller of high bandwidth by photo-detector, the servo controller pair
The voltage signal received handled after there is provided a negative feedback control signal to intensity modulator.Then, intensity modulator
Suppress the intensity noise of subsequently received optical signal using above-mentioned negative feedback control signal.
Digital intensity noise Restrain measurement based on intensity modulator mainly includes high speed intensity modulator, fiber coupling
Device, photodetector, wave filter and broadband control circuit.The program mainly includes：The optical signal that intensity modulator is exported is entered
Row sampling obtains voltage signal, and the voltage signal is demodulated, and control signal, the control letter are produced according to demodulation result
Number include the tune that the power control signal that is adjusted to optical signal power and the operating point to intensity modulator are adjusted
Square-wave signal processed.Control power signal of the intensity modulator in the control signal received is to the optical signal that receives
Power be modulated, the modulated square wave signal in the control signal received is carried out to the operating point of intensity modulator
Adjustment, makes the operating point of intensity modulator keep stable.The program has the disadvantage that：
1) for the working point control of intensity modulator, the scheme of detection modulated square wave has been used.In the program, it is necessary to
Introduce modulated square wave signal.The introducing of the signal, can influence suppression during intensity modulator normal work for intensity noise to imitate
Really, it is also a kind of introducing of noise while the modulated square wave signal is for suppressing the process of noise.For noise suppressed system
For system, the new noise that introduces has very big harm for system, results even in the failure of whole suppression system.
2) in the program, the closed loop restrainable algorithms subproblem that intensity noise suppresses is more, the effect of closed loop feedback control
Not substantially, while in closed loop restrainable algorithms, not considering the link of phase compensation, closed loop is caused to produce phase drift in suppressing
Move, the effect that the phase drift directly results in suppression noise in closed loop procedure is not played well.
In the analog feedback control program of use intensity modulator, the analog servomechanism circuit that high bandwidth servo loop is used,
The structure of the program is as shown in Figure 2.As can be seen that the closed loop feedback scheme and the digital intensity noise suppression based on intensity modulator
Scheme processed is similar, but the program uses analog servomechanism controller, while not suppressing to intensity modulator.The party
The sketch of servo loop in case is as shown in figure 3,301 and 302 indicated is two operational amplifiers.Servo control loop
First order discharge circuit amplifies for high-pass filtering, only provides gain to frequency more than bias modulation frequency.Adjusted less than biasing
In the frequency of frequency processed, the gain very little of first order discharge circuit is determined by electric capacity C1, resistance R1 and resistance R3.The peak of gain
Value is generally present near bias modulation frequency, and is determined by resistance R1 and electric capacity C2.In order that servo loop is stable, when total
When open-loop gain is more than 1, the gain of this one-level should remain constant.The second level discharge circuit of servo loop is similarly high pass
Filter and amplification, only provides gain to frequency more than bias modulation frequency, in the frequency less than bias modulation frequency, and signal increases
Beneficial very little.The program has two：
1) Primary Component used in the program is intensity modulator, and major issue present in its work is exactly that intensity is adjusted
The drifting problem of device operating point processed, the operating point of the device is highly prone to the change of the environmental factors such as environment temperature, humidity and electromagnetic field
The influence of change, the drift of operating point directly results in system and declined for intensity noise inhibition, and control signal is unstable, even
Whole suppression system is set to fail.But any technology is not used in the program to solve this problem.
2) control accuracy in analog servomechanism loop is relatively low in the program, and the effect suppressed to intensity noise is poor, while by
In using analog circuit to be controlled, change suppresses fairly cumbersome during frequency range, it is necessary to be carried out to whole servo control loop
Change.
The content of the invention
The present invention is improved to the digital closed loop scheme that the intensity noise based on intensity modulator suppresses, in order to
The closed-loop precision for solving to occur in similar scheme at present is bad, the problem of noise suppression effect is poor, meanwhile, the present invention also reach compared with
Good noise suppression effect, improves the signal to noise ratio of optical fibre gyro light source.
Suppress digital double closed-loop method the invention provides a kind of light source intensity noise based on intensity modulator, based on existing
There is the light source intensity noise Restrain measurement of intensity modulator, using the scheme of digital double closed-loop, use two closed loops, difference
For carrying out the suppression of intensity noise and the stabilization of intensity modulator operating point, the first closed loop use intensity modulator is carried out
The suppression of intensity noise, the second closed loop is used for the bias voltage of strength of stability modulator operating point, or is strength of stability
The offset operation point of modulator, makes the offset operation point of intensity modulator no longer drift about, working stability.
The bias voltage of second closed-loop stabilization intensity modulator operating point in the present invention, including start job search point and work
As when be controlled two parts.
Start job search point be specifically：The bias voltage of intensity modulator is scanned, from-VπScan Vπ, VπFor
The half-wave voltage of intensity modulator, the output voltage of photodetector when recording each scan values, finds the defeated of photodetector
Go out the maximum and minimum value of voltage, correspondence finds bias voltage V during intensity modulator maximum output luminous power pointb0maxMost
Bias voltage V during small Output optical power pointb0min, then start shooting and the bias voltage V of intensity modulator be setb0For：
Vb0The desired output voltage of photodetector when the output voltage of corresponding photodetector is operating point.
It is controlled specifically during work：The output voltage of photodetector is monitored in real time, by the reality of photodetector
The desired output voltage of photodetector is compared when output voltage is with operating point, obtains corresponding bias voltage difference, will
Obtained bias voltage difference feeds back to intensity modulator, controls the bias voltage of intensity modulator in [Vb0-a,Vb0+ b] in,
Wherein parameter a and b values are within [0,0.5].
It is the step of the suppression of the first closed loop use intensity modulator progress intensity noise in the present invention：
1st step, is pre-processed to the light intensity signal that photodetector is exported, and the low-frequency component in removal light intensity signal is simultaneously
Light intensity signal is digitized；
2nd step, obtained digital luminous intensity signal is filtered, and keeps the phase stabilization of signal；
3rd step, phase compensation is carried out to filtered digital luminous intensity signal, is specifically：According to the time at centre frequency
Delay, time bias is carried out in full frequency band to filtered signal；
4th step, is converted to simulation light intensity signal by the digital luminous intensity signal after phase compensation, feeds back to intensity modulated
The radio frequency control end of device.
Advantages of the present invention is with good effect：
(1) present invention is suppressed using the scheme of digital double closed-loop to optical fibre gyro with the intensity noise of light source, is solved
Closed-loop precision is bad, the problem of noise suppression effect is poor, reaches preferable noise suppression effect, improves optical fibre gyro light source
Signal to noise ratio, improves the performance of whole system, and digital stream network loop is used in the present invention, and change suppresses only to need during frequency range
The program changed in digital logic device can be changed to suppressing frequency range；
(2) present invention uses new noise suppressing method, noise suppressed can be made to reach preferably effect, greatly carried
The high effect of noise suppressed, while the phase delay to noise suppressing method is controlled and compensated so that whole system
Kept in phase stable so that influence of the phase to closed loop noise suppressed is minimized；
(3) in the second closed loop that offset operation point is controlled, present invention uses the method for mean power, it is to avoid
The scheme for adding modulated square wave is the influence of intensity noise suppression for intensity modulator normal work；In the control of offset operation point
In, in addition to being added without modulated signal, the coefficient in used mean power can be according to the requirement of controlled operating point
Change and change, controlled intensity modulator can be made to be operated in minimum point, intermediate point and peak.
Brief description of the drawings
Fig. 1 is the structural representation for suppressing light source intensity noise using high speed intensity modulator；
Fig. 2 is the analog feedback control program schematic diagram of use intensity modulator；
Fig. 3 be use intensity modulator analog feedback control program in servo control loop structural representation；
Fig. 4 is that the light source intensity noise of the present invention suppresses the principle schematic of digital double closed-loop method；
Fig. 5 is intensity modulator P-V curve maps.
Embodiment
Below in conjunction with drawings and examples, the present invention is described in further detail.
The light source intensity noise based on intensity modulator of the present invention suppresses digital double closed-loop method, using digital double closed-loop
Scheme, using two closed loops, be respectively intended to carry out suppression and the stabilization of intensity modulator operating point of intensity noise, and
Two big improvement have been carried out to similar scheme before.The present invention proposes a kind of new closed loop noise suppressing method first, uses
The design philosophy design noise suppressing method of wave filter is optimized, the noise suppressing system is reached preferable effect.Institute
In the closed loop suppressing method used, the link of signal phase delay compensation is added so that keep stable in whole system phase,
So that influence of the phase to closed loop noise suppressed is minimized.The closed loop suppressing method can obtain the effect of closed loop noise suppressed
To very big raising, most noises can be inhibited.Secondly the present invention is directed to the point control of intensity modulator offset operation
Loop processed is optimized, and devises offset operation point closed loop feedback new departure.Side for needing addition modulated square wave before
Case is improved, used mean power method, it is to avoid before add modulated square wave in scheme for intensity modulator just
Normal work is the influence that intensity noise suppresses.Simultaneously by the process of an initialization, reduce in the course of work and bias as far as possible
Voltage fluctuates widely.
System used in the present invention is the digital double closed-loop intensity noise suppression system based on intensity modulator.Using strong
What degree modulator suppressed optical fibre gyro light source intensity noise had certain application, and the program is mainly characterized by using strong
Spend modulator and carry out closed loop feedback control, by the output of adjusting strength modulator, reach the purpose for suppressing light source intensity noise.
Due to the rapidity and convenience of digital closed loop, intensity modulator is controlled using the method for digital closed loop, and then
Light source intensity noise is suppressed.Simultaneously as in the course of work of intensity modulator, it may appear that the drift of operating point, shadow
The work of intensity modulator is rung, it is equally utilized in the present invention that the method for digital closed loop carrys out the drift of the operating point of inhibition strength modulator
Move, therefore the present invention suppresses the intensity noise of optical fibre gyro light source using the method for digital double closed-loop.
The light source intensity noise based on intensity modulator of the present invention suppresses principle such as Fig. 4 institutes of digital double closed-loop method
Show.As shown in figure 4, in the scheme of the two close cycles, the first closed loop obtains the strength signal of light source by photodetector, and passes through
Digital filtering and phase compensation processing, obtain the value of feedback of digital closed loop, feed back to intensity modulator, real by intensity modulator
Now the closed loop feedback to intensity noise suppresses；Second closed loop obtains the strength signal of light source by photodetector, passes through light intensity
Signal obtains the power signal by intensity modulator, and then by power detection method, obtains the biasing work of intensity modulator
Make the burning voltage of point, and be added in intensity modulator, realize the closed loop feedback control to the offset operation point of intensity modulator.
Intensity noise suppressing method proposed by the invention includes following steps, wherein, the 2nd step and the 3rd step be
Realized in the servo controller in high broadband：
1st step, is pre-processed to the light intensity signal that photodetector is exported, and the low-frequency component in removal light intensity signal is simultaneously
Light intensity signal is digitized.It is the high frequency noise content in light source due to the suppression target that intensity noise suppresses, therefore is locating in advance
During reason, low frequency noise component is filtered out, it is to avoid influence is produced on follow-up signal processing.Simultaneously as photodetector output
Light intensity signal is analog signal, so must be sampled, obtains digital luminous intensity signal for digital closed loop processing.
2nd step, by the digital luminous intensity signal obtained by pretreatment by the noise servo suppression system of design, enters line number
Word is filtered, to keep the phase stabilization of signal.I.e. noise servo suppression system filtering system.
The design method of this step noise servo suppression system is as follows：
Noise servo suppression system in the closed loop carries out fast closed-loop feedback control due to needing, therefore for system
Phase delay has very high requirement, it is necessary to keep strict accurate phase-delay characteristic.The present invention uses optimized design
Method carries out the design of noise servo suppression system, and such design method can ensure phase-delay characteristic, while making phase
Position delay is minimum so that fast closed-loop feedback control is possibly realized.The method of optimal design is exactly the zero point for adjusting filtering system
Distributing position so that actual frequency response H (ejω) and ideal frequency response Hd(ejω) between absolute deviation it is minimum, ω is represented
Angular frequency, j represents imaginary part.Such a optimal design side of the ripple approximatioss such as Chebyshev is used in the embodiment of the present invention
Method, optimal filtering system is obtained using the criterion of " worst error is minimum ", and optimum solution is unique.Other filters can also be used
Ripple algorithm, the compensation to phase delay as long as preferable filter effect can be reached, and can make phase keep stable.
Chebyshev's equiripple approximation is to use Weighted approximation error E (ejω) minimum starting point design filtering system
Method.
E(ejω)=W (ejω)[Hd(ejω)-H(ejω)] (1)
In formula, W (ejω) it is weighting function, in the high frequency range of tolerance, larger weighted value can be taken, is otherwise taken
Less weighted value.For this filtering system, H (ejω) can be expressed as
The equation is the error equation of the filtering system, wherein, M represents the sampled point before this filtering sampling
Number, h (k) represents the frequency response values at k points.
Due to the phase characteristic of filtering system can be ensured by symmetry, so design can only consider amplitude versus frequency characte
Without considering phase-frequency characteristic.Therefore, it is possible to useTo replace H (ejω), i.e.,
Calculated using the approximate error equation, calculated, filtered using Lei meter Zi algorithms during calculating
System transter H (z), z are complex variable.
3rd step, phase compensation is carried out by the signal of filtering system by Phase Compensation Algorithm again.Due to the filtering system
Linear phase characteristic, phase delay is certain, so phase compensation can be converted into time bias herein.In the present invention
In, time bias part is realized by all-pass filter, i.e., it is advanced to carry out certain phase to signal on full frequency band.By estimating
The phase delay of filter system is calculated, and estimates the time delay at centre frequency, phase compensation is carried out for centre frequency, adopts
Sample all-pass filter carries out time bias, can also have preferable phase compensation effect in other frequency ranges that need to suppress.
4th step, intends (DAC) processing by digital revolving die by the digital luminous intensity signal after phase compensation, is converted to mould
Intend light intensity signal, feed back to radio frequency (RF) control end of intensity modulator, reach the purpose of frequency range intensity noise required for suppressing.
On the basis of new intensity noise suppressing method is proposed, present invention uses new intensity modulator offset operation
Point control program.The new technology needs addition modulated square wave to be just biased the shortcoming of working point control before solving, keep away
Exempt to add the influence that modulated square wave suppresses intensity modulator normal work i.e. intensity noise.The principle of the program is as follows：
Intensity modulator is made up of double Y waveguides, and operation principle is equivalent to Mach-Zehnder type interferometers, during work, by force
The operating point of degree modulator is highly prone to the influence of environmental factor, the problem of there is drift.
The output signal function expression of intensity modulator is as follows：
Relation between this function representation intensity modulator output intensity and input light intensity and bias voltage.PoutIt is
The luminous power of intensity modulator output；PinIt is the luminous power of input；Vb0It is the bias voltage of operating point, Vbm(t) when being t
The operating voltage of intensity modulator, i.e. modulation voltage；VπIt is the canonical parameter i.e. half-wave voltage of intensity modulator, represents intensity
The output of modulator from maximum be transferred to minimum when required change magnitude of voltage；It is due to that outside environmental elements are such as stable, shakes
It is dynamic to cause the random phase shift of operating point drift.Therefore V is worked asbm(t) when being zero, i.e., when intensity modulator does not work, P-V relation curves
As shown in Figure 5.In Fig. 5, abscissa represents bias voltage Vb, ordinate represents Output optical power Pout。
As seen from Figure 5, when intensity modulator is operated in Quad+ or Quad-, P-V curve approximations in linear, this
When power output be peak power and minimum power median.At this moment operating voltage V is addedbm(t) operating voltage can, be caused
Produced effect is similar to linearly, therefore should be by the offset operation point control of intensity modulator in this place.Because intensity is adjusted
Device processed is influenceed that operating point drift can be caused by outside environmental elements, therefore the present invention devises intensity modulator offset operation
The stable closed loop of point.Here, the present invention, without adding low-frequency modulation signal, also would not using the scheme of power measurement
Influence the normal work of intensity modulator.Its operation principle is as described below：
Due to shown in the output signal function such as formula (4) of intensity modulator, when intensity modulator is not started working, Vbm
(t) voltage is zero, and above formula can be rewritten as：
It is recognised that as output voltage PoutObtain maximum PoutmaxWhen, the right of formula (5) obtains maximum, now
I.e.
Assuming that k=0, can obtain bias voltage V during intensity modulator maximum output luminous power pointb0maxValue be
As output voltage PoutObtain minimum value PoutminWhen, the right of formula (5) obtains minimum value, now
I.e.
Assuming that k=0, can obtain bias voltage V during intensity modulator minimum Output optical power pointb0minFor
When intensity modulator is operated in desired linear work point, power output is peak power output and minimum output
The median of power.Therefore, the present invention calculates corresponding bias voltage value P during linear work point according to following formulaOperating pointIt is as follows：
By PoutmaxAnd PoutminSubstituting into above formula can obtain：
Output signal function during operating point is as follows：
By upper (13) and (14) two formulas, it can obtain, at operating point：
It can be solved by above formula,V when can further solve operating pointb0Value be
Can be by V during operating pointb0By Vb0minAnd Vb0maxTo represent：
Therefore, the step of present invention is controlled using the method progress intensity modulator offset operation point of mean power is as follows：
The scheme of mean power measurement carries out intensity modulator offset operation point stabilization, including start job search point and work
Two parts of control for a long time are carried out when making.
The process that start operating point is found is as follows：
The scanning of voltage is biased to intensity modulator by servo controller, from-VπScan Vπ, sweep spacing is set
For 0.01V.VπIt is the half-wave voltage of intensity modulator.Sweep spacing can be set as needed, be set in the embodiment of the present invention
0.01V can obtain accurate operating bias voltage, and need not record the scan values of much larger number.
During bias voltage is scanned, the magnitude of voltage that photodetector is exported when recording each scan values.Due to light
The magnitude of voltage relation proportional to the Output optical power of intensity modulator of electric explorer output, therefore recording voltage value can be passed through
The Output optical power of intensity modulator is obtained indirectly.By recording the magnitude of voltage that photodetector is exported, wherein light can be obtained
The maximum and minimum value of electric explorer output voltage.The two points are the maximum output luminous power point of intensity modulator
PoutmaxWith minimum Output optical power point Poutmin。
Then correspond to bias voltage V when can check in maximum output luminous power point and minimum Output optical power pointb0maxWith
Vb0min.Bias voltage V when can obtain correct bias operating point by the formula (17) released aboveb0。
Now start scanning process terminates, the V of outputb0The bias voltage of as correct operating point, sets intensity modulated
The bias voltage of device start is Vb0。
During work, it is as follows that servo controller carries out the stable process of intensity modulator offset operation point：
Output optical power of the intensity modulator in operating point photodetector corresponding with its is obtained by scanning of starting shooting defeated
Go out voltage, operationally, by monitoring in real time, obtain real-time photodetector output voltage.Looked for by inquiry scan record
To Vb0The output voltage of corresponding photodetector, regard the voltage as the preferable output voltage of photodetector during operating point.
The preferable output voltage of photodetector is compared during by real-time photodetector output voltage with operating point
Compared with, the difference of actual output voltage and desired output voltage is obtained, corresponding bias voltage difference is obtained according to the difference, will be inclined
Direct current (DC) end that voltage difference inputs to intensity modulator as value of feedback is put, the bias voltage and V of intensity modulator is controlledb0
Between error be maintained in real time within a limit value, and then reach that closed loop is adjusted in real time.For example, setting control intensity modulated
The bias voltage of device is in [Vb0-a,Vb0+ b] in, wherein parameter a and b values can be come according to specific needs within [0,0.5]
Setting.The magnitude of voltage relation proportional to the Output optical power of intensity modulator of photodetector output, according to scanning before
Record value can calculate the proportionate relationship between the output voltage of photodetector and the bias voltage of intensity modulator.Obtaining
After the actual output voltage of photodetector, the ratio obtained by the scanning record value before inquiry or according to calculating is closed
System, can obtain the corresponding bias voltage of actual output voltage and operating bias voltage V of photodetectorb0Difference, will
To bias voltage difference cutting in intensity modulator, with the bias voltage of strength of stability modulator operating point.
Claims (2)
1. a kind of light source intensity noise based on intensity modulator suppresses digital double closed-loop method, using two closed loops, the
One closed loop use intensity modulator carries out the suppression of intensity noise；It is characterized in that：Second closed loop is used for stable strong
Spend the bias voltage of modulator operating point；The bias voltage of strength of stability modulator operating point includes start job search point and work
As when be controlled two parts；
Described start job search point, be specifically：The bias voltage of intensity modulator is scanned, from-VπScan Vπ,
VπFor the half-wave voltage of intensity modulator, the output voltage of photodetector, finds photodetector when recording each scan values
Output voltage maximum and minimum value, bias voltage V when correspondence finds intensity modulator maximum output luminous power pointb0max
Bias voltage V during with minimum Output optical power pointb0min；Then start sets the bias voltage V of intensity modulatorb0For：
Vb0The desired output voltage of photodetector when the output voltage of corresponding photodetector is operating point；
It is controlled during described work, is specifically：The output voltage of monitoring photodetector, compares photodetector in real time
The desired output voltage of photodetector when actual output voltage is with operating point, obtains corresponding bias voltage difference, will bias
Voltage difference feeds back to intensity modulator, controls the bias voltage of intensity modulator in [Vb0-a,Vb0+ b] in, wherein parameter a and
B values are within [0,0.5]；
Described use intensity modulator carries out the suppression of intensity noise, comprises the following steps that：
1st step, is pre-processed to the light intensity signal that photodetector is exported, the low-frequency component in removal light intensity signal and by light
Strong signal digitlization；
2nd step, obtained digital luminous intensity signal is filtered, and keeps the phase stabilization of signal；
3rd step, phase compensation is carried out to filtered digital luminous intensity signal, is specifically：According to the time delay at centre frequency,
Time bias is carried out to filtered signal in full frequency band；
4th step, is converted to simulation light intensity signal by the digital luminous intensity signal after phase compensation, feeds back to intensity modulator
Radio frequency control end.
2. a kind of light source intensity noise based on intensity modulator according to claim 1 suppresses digital double closed-loop method,
Characterized in that, the bias voltage to intensity modulator is scanned, setting sweep spacing is 0.01V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410462716.3A CN104236537B (en) | 2014-09-12 | 2014-09-12 | Light source intensity noise based on intensity modulator suppresses digital double closed-loop method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410462716.3A CN104236537B (en) | 2014-09-12 | 2014-09-12 | Light source intensity noise based on intensity modulator suppresses digital double closed-loop method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104236537A CN104236537A (en) | 2014-12-24 |
| CN104236537B true CN104236537B (en) | 2017-08-11 |
Family
ID=52225083
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410462716.3A Active CN104236537B (en) | 2014-09-12 | 2014-09-12 | Light source intensity noise based on intensity modulator suppresses digital double closed-loop method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104236537B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104991180A (en) * | 2015-07-15 | 2015-10-21 | 国网智能电网研究院 | Photoelectric detector assembly bandwidth detecting method and device |
| CN105807656B (en) * | 2016-03-09 | 2018-05-08 | 宁波中物东方光电技术有限公司 | Optical crystal control method based on Segmented Extreme Value search with multiple spot judgement |
| CN106017449B (en) * | 2016-05-31 | 2018-09-21 | 东南大学 | A kind of system improving atmospheric packaged silicon micro-gyroscope zero bias performance |
| CN110319827B (en) * | 2019-07-17 | 2020-01-31 | 北京航空航天大学 | light source relative intensity noise self-adaptive suppression device for fiber optic gyroscope |
| CN111044027B (en) * | 2020-01-02 | 2021-09-17 | 浙江大学 | Method for demodulating signal by using open-loop optical fiber gyroscope signal processing circuit |
| CN111290041B (en) * | 2020-03-19 | 2022-06-21 | 之江实验室 | Method and device for suppressing intensity noise of light source by utilizing proportional compensation of electro-optic modulator |
| CN111854802B (en) * | 2020-07-28 | 2021-05-18 | 武汉长盈通光电技术股份有限公司 | Optical path contrast detection method for fiber-optic gyroscope |
| CN113675724B (en) * | 2021-08-23 | 2022-11-18 | 北京航空航天大学 | Temperature drift suppression method for laser light stabilizing intensity system capable of delaying and expanding compensation quantity |
| CN113922884B (en) * | 2021-08-30 | 2023-02-28 | 北京航天控制仪器研究所 | Carrier suppression device and method for electro-optical modulator |
| CN114039666B (en) * | 2021-11-26 | 2023-02-21 | 济南量子技术研究院 | Intensity modulation device, stability control method thereof and QKD system |
| CN116026310B (en) * | 2023-03-30 | 2023-06-16 | 中国船舶集团有限公司第七〇七研究所 | Integrated optical gyroscope, modulation system and light source noise suppression method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5602642A (en) * | 1995-06-07 | 1997-02-11 | Honeywell Inc. | Magnetically insensitive fiber optic rotation sensor |
| CN102269590A (en) * | 2011-05-03 | 2011-12-07 | 北京航空航天大学 | Apparatus and method for inhibiting intensity noise in optical signal |
| CN102650524A (en) * | 2012-04-25 | 2012-08-29 | 北京航空航天大学 | Differential dual-interference type closed loop fiber optic gyroscope based on birefringence modulation of wide frequency light source |
| CN102706362A (en) * | 2012-05-24 | 2012-10-03 | 湖北航天技术研究院总体设计所 | Optical power self-correction method for fiber-optic gyroscope and high-precision fiber-optic gyroscope using same |
| CN102818565A (en) * | 2012-08-09 | 2012-12-12 | 浙江大学 | Suppression method of relative intensity noise of light source of fiber-optic gyroscope |
| US8542364B1 (en) * | 2009-12-17 | 2013-09-24 | Honeywell International Inc. | System to reduce gyroscopic errors with limited power supply quality in a fiber optic gyroscope |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2849734B2 (en) * | 1994-06-22 | 1999-01-27 | 日本航空電子工業株式会社 | Fiber optic gyro |
| US8717575B2 (en) * | 2011-08-17 | 2014-05-06 | Honeywell International Inc. | Systems and methods for environmentally insensitive high-performance fiber-optic gyroscopes |
-
2014
- 2014-09-12 CN CN201410462716.3A patent/CN104236537B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5602642A (en) * | 1995-06-07 | 1997-02-11 | Honeywell Inc. | Magnetically insensitive fiber optic rotation sensor |
| US8542364B1 (en) * | 2009-12-17 | 2013-09-24 | Honeywell International Inc. | System to reduce gyroscopic errors with limited power supply quality in a fiber optic gyroscope |
| CN102269590A (en) * | 2011-05-03 | 2011-12-07 | 北京航空航天大学 | Apparatus and method for inhibiting intensity noise in optical signal |
| CN102650524A (en) * | 2012-04-25 | 2012-08-29 | 北京航空航天大学 | Differential dual-interference type closed loop fiber optic gyroscope based on birefringence modulation of wide frequency light source |
| CN102706362A (en) * | 2012-05-24 | 2012-10-03 | 湖北航天技术研究院总体设计所 | Optical power self-correction method for fiber-optic gyroscope and high-precision fiber-optic gyroscope using same |
| CN102818565A (en) * | 2012-08-09 | 2012-12-12 | 浙江大学 | Suppression method of relative intensity noise of light source of fiber-optic gyroscope |
Non-Patent Citations (2)
| Title |
|---|
| 光强外调制法抑制相对强度噪声;徐建营等;《中国惯性技术学报》;20081231;第16卷(第6期);正文第1节及图1 * |
| 高精度光纤陀螺光源强度噪声的抑制;李绪友等;《中国惯性技术学报》;20101031;第18卷(第5期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104236537A (en) | 2014-12-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104236537B (en) | Light source intensity noise based on intensity modulator suppresses digital double closed-loop method | |
| CN108007550B (en) | Improved PGC modulation-demodulation detection method | |
| CN110319827B (en) | light source relative intensity noise self-adaptive suppression device for fiber optic gyroscope | |
| JP4426292B2 (en) | Method and apparatus for detection and control of light beam alignment | |
| US9518825B2 (en) | Suppression of lock-in effect due to a MIOC frequency response in a fiber-optic Sagnac interferometer | |
| CN102147254A (en) | Four-frequency laser gyro control method | |
| CN105867497B (en) | A kind of MZ modulators bias voltage self-adaptation control method | |
| US20130044328A1 (en) | Systems and methods for environmentally insensitive high-performance fiber-optic gyroscopes | |
| CN105911869A (en) | Interference observation-based quick reflector disturbance suppression method | |
| CN101975574A (en) | Small jitter frequency stabilization method of four-frequency laser gyro | |
| CN102692314A (en) | Apparatus and method for testing power spectral density of frequency noise of laser based on fiber resonator | |
| CN110749875A (en) | Laser pulse adjusting module of pilot frequency self-adaptive Mach-Zehnder modulator | |
| CN111462707B (en) | Modeling compensation-based temperature drift suppression method for liquid crystal power stabilizing system | |
| CN107332607B (en) | A kind of Now therefore to all whom it may concern ASE compensating parameter acquisition methods and acquisition device | |
| Deng et al. | On vibration rejection of nonminimum-phase long-distance laser pointing system with compensatory disturbance observer | |
| JP2013213721A (en) | Object movement controlling device and fourier transform infrared spectrophotometer | |
| CN110609475A (en) | Virtual double closed-loop control method based on improved extended state observer | |
| CN112781578B (en) | Optical fiber gyroscope with scale factor self-adaptive control and method | |
| CN105953725A (en) | Phase carrier type laser interference signal closed-loop demodulation method | |
| CN105334644B (en) | The accuracy control method of lithium niobate external modulator | |
| CN112815935A (en) | Device and method for evaluating dynamic characteristics of fiber-optic gyroscope | |
| US20060051087A1 (en) | Method for determining the signal-to-noise ratio of an optical signal | |
| CN110879532B (en) | Control system and design method | |
| CN107576323A (en) | Based on the combined optical fibre gyro filtering method of FIR and LMS adaptive-filterings | |
| US9677941B2 (en) | Object movement control device and fourier transform infrared spectrophotometer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information |
Inventor after: Li Lijing Inventor after: Zheng Yue Inventor after: Wei Chao Inventor after: Yang Dewei Inventor after: Zhang Chunxi Inventor before: Xu Wenyuan Inventor before: Wei Chao Inventor before: Yang Dewei Inventor before: Li Lijing Inventor before: Zhang Chunxi |
|
| COR | Change of bibliographic data | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |