CN111327366B - System and method for fast locking minimum bias point of electro-optic intensity modulator - Google Patents
System and method for fast locking minimum bias point of electro-optic intensity modulator Download PDFInfo
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- CN111327366B CN111327366B CN202010306364.8A CN202010306364A CN111327366B CN 111327366 B CN111327366 B CN 111327366B CN 202010306364 A CN202010306364 A CN 202010306364A CN 111327366 B CN111327366 B CN 111327366B
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- 238000000034 method Methods 0.000 title claims abstract description 13
- 230000008033 biological extinction Effects 0.000 claims abstract description 14
- 230000005540 biological transmission Effects 0.000 claims abstract description 13
- 239000013307 optical fiber Substances 0.000 claims description 23
- 230000010287 polarization Effects 0.000 claims description 14
- 238000001914 filtration Methods 0.000 claims description 5
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 claims description 3
- 230000010354 integration Effects 0.000 claims 1
- 238000004891 communication Methods 0.000 abstract description 6
- 230000003287 optical effect Effects 0.000 abstract description 6
- 238000013461 design Methods 0.000 abstract description 2
- 239000000835 fiber Substances 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 230000032683 aging Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
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- 239000000758 substrate Substances 0.000 description 1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/54—Intensity modulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/70—Photonic quantum communication
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Abstract
The invention discloses a system and a method for rapidly locking a minimum bias point of an electro-optic intensity modulator. The method of the invention utilizes the electro-optic intensity modulator to obtain an error signal corresponding to a transmission curve by periodically modulating the single photon signal distribution probability and demodulating the corresponding TTL signal with the same frequency, uses the error signal to continuously tune the bias voltage to lock the minimum bias point of the transmission curve in real time, and obtains the single photon pulse output with long time and high extinction ratio. The invention solves the problem that the minimum bias point of the electro-optic intensity modulator cannot be directly locked at the single photon intensity. The invention has reasonable design, simple locking system, high locking precision and high stability, and can be applied to the fields of quantum communication, optical sensing and the like.
Description
Technical Field
The invention relates to the technical fields of quantum communication, optical sensing and the like, in particular to a system and a method for rapidly locking a minimum bias point of an electro-optical intensity modulator.
Background
The single photon pulse with high extinction ratio has important application in the fields of quantum communication, optical sensing and the like, in the field of quantum communication, the higher the extinction ratio of the single photon pulse is, the higher the interference visibility is, the lower the corresponding communication error rate is, in the field of optical sensing, the higher the extinction ratio of the single photon pulse is, the smaller the measurement error is, and the higher the corresponding measurement accuracy is, so that the single photon pulse with high extinction ratio is widely paid attention to how to obtain. The electro-optic intensity modulator is a device for realizing laser intensity modulation based on a crystal electro-optic effect, the bias point of the electro-optic intensity modulator is usually set at a transmission minimum point, and an electric pulse signal is loaded at a radio frequency end to modulate an input continuous single photon signal into a single photon pulse with high extinction ratio. However, the bias point drifts due to external mechanical vibration, ambient temperature changes, instrument aging, and the like. At this time, the pulsed light substrate may split a part of energy, resulting in a decrease in extinction ratio of the single photon pulse, and thus it is necessary to lock the minimum bias point of the electro-optical intensity modulator to output a high extinction ratio single photon pulse. The traditional locking method is based on classical strong light, and can not be directly locked at single photon intensity.
Disclosure of Invention
In order to solve the problem that the minimum bias point of the electro-optic intensity modulator cannot be directly locked at the single photon intensity in the prior art, the invention aims to provide a system and a method for rapidly locking the minimum bias point of the electro-optic intensity modulator, which can automatically lock the minimum bias point in real time at the single photon intensity so as to output single photon pulse with high extinction ratio for a long time, and the locking system is simple, high in locking precision and high in stability.
The invention is realized by adopting the following technical scheme:
a system for quickly locking minimum bias point of electro-optical intensity modulator is composed of laser, attenuator, electro-optical intensity modulator, optical fiber coupler, single-photon detector, phase-locked amplifier, signal generator, first adder, analog proportional-integral-differential controller, second adder and digital delay pulse generator.
The output end of the photoelectric intensity modulator is connected with the input end of the optical fiber coupler, the first output end of the optical fiber coupler is used as a signal output end (used for scientific research), the second output end of the optical fiber coupler is connected with the input end of the single photon detector, the output end of the single photon detector is connected with the input end of the phase-locked amplifier, the output end of the phase-locked amplifier is connected with the input end of the analog proportional integral differential controller, the output end of the signal generator is connected with the first input end of the first adder, the output end of the analog proportional integral differential controller is connected with the second input end of the first adder, the output end of the first adder is connected with the bias end of the photoelectric intensity modulator, the modulation output end of the phase-locked amplifier is connected with the first input end of the second adder, the first output end of the digital delay pulse generator is connected with the second input end of the second adder, the output end of the second adder is connected with the radio frequency delay pulse generator, and the second output end of the digital delay pulse generator is connected with the photon generator.
The method for rapidly locking the minimum bias point of the electro-optical intensity modulator by using the system comprises the following steps:
the laser outputs linear polarization laser signals transmitted along the slow axis of the polarization maintaining fiber, the laser signals enter the attenuator to reduce the intensity to a single photon level, and then the single photon signals are transmitted along the slow axis of the polarization maintaining fiber to enter the electro-optic intensity modulator to be modulated.
The digital delay pulse generator outputs one path of TTL pulse to be loaded to the radio frequency end of the electro-optic intensity modulator through the second adder, the digital delay pulse generator is used for cutting continuous light into single photon pulse light, the modulated single photon pulse is transmitted along the polarization maintaining optical fiber slow axis and enters the optical fiber coupler to be divided into two beams, one beam of single photon pulse is used for scientific research, the other beam of single photon pulse is detected by the single photon detector, the digital delay pulse generator outputs the other path of TTL pulse as a trigger clock of the single photon detector, the time interval of the two paths of TTL pulses is adjusted to enable the photon count acquired by the single photon detector to be maximum, and the single photon detector converts the single photon pulse light into the TTL signal to be input into the phase-locked amplifier.
The phase-locked amplifier demodulates the modulated TTL signal, namely, the TTL signal and the modulated signal with the same frequency are mixed and subjected to low-pass filtering to obtain an error signal for locking a minimum offset point, the integral time, sensitivity, filtering slope and phase of the modulated signal of the phase-locked amplifier are regulated to enable the signal-to-noise ratio of the error signal to be maximum, the central position of the error signal corresponds to the minimum offset point of a transmission curve, and the error signal is used for tracking and locking the minimum offset point in real time.
The error signal is optimized by the analog proportional-integral-differential controller and then is loaded to the bias end of the electro-optic intensity modulator through the first adder, the triangular wave scanning signal output by the signal generator is switched into direct current voltage, the voltage amplitude and the parameters of the analog proportional-integral-differential controller are adjusted, the amplitude of the error signal is enabled to be minimum, the error signal achieves real-time locking of the minimum bias point of the electro-optic intensity modulator through continuous tuning of the bias voltage, and long-time high extinction ratio single photon pulse output is obtained.
The invention utilizes the electro-optic intensity modulator to modulate single photon signals through periodical intensity, demodulates photoelectric converted TTL signals with the same frequency to obtain error signals corresponding to the transmission curve, and uses the error signals to continuously tune bias voltage to lock the minimum bias point of the transmission curve in real time. The method solves the problem that the minimum bias point of the electro-optic intensity modulator cannot be directly locked at the single photon intensity.
The invention has reasonable design and good practical application value.
Drawings
FIG. 1 shows a schematic diagram of the connection of the system of the present invention (dashed lines represent optical signals transmitted by polarization maintaining fibers and solid lines represent electrical signals).
Fig. 2 shows a transmission diagram of an electro-optical intensity modulator.
Fig. 3 shows an error signal for locking the minimum bias point.
In the figure: the device comprises a 1-laser, a 2-attenuator, a 3-electro-optical intensity modulator, a 4-optical fiber coupler, a 5-single photon detector, a 6-phase-locked amplifier, a 7-signal generator, an 8-first adder, a 9-analog proportional-integral-differential controller, a 10-second adder and an 11-digital delay pulse generator.
Detailed Description
Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
A system for fast locking minimum bias point of electro-optic intensity modulator, as shown in fig. 1, comprises a laser 1 (orbit light, ETH), an attenuator 2, an electro-optic intensity modulator 3, a fiber coupler 4 (THORLABS, PN1550R5 A1), a single photon detector 5 (Quantum, QCD 300), a lock-in amplifier 6 (SRS, SR 830), a signal generator 7 (Tektronix, AFG 3102), a first adder 8, an analog proportional-integral-derivative controller 9 (SRS, SIM 960), a second adder 10, a digital delay pulse generator 11 (SRS, DG 645).
As shown in fig. 1, a classical linear polarization laser signal output by a laser enters an electro-optical intensity modulator 3 after passing through an attenuator 2, the output end of the electro-optical intensity modulator 3 is connected with the input end of an optical fiber coupler 4, a first output end output signal of the optical fiber coupler 4 is used for scientific research, a second output end of the optical fiber coupler 4 is connected with the input end of a single photon detector 5, the output end of the single photon detector 5 is connected with the input end of a phase-locked amplifier 6, the output end of the phase-locked amplifier 6 is connected with the input end of an analog proportional integral differential controller 9, the output end of a signal generator 7 is connected with the first input end of a first adder 8, the output end of the analog proportional integral differential controller 9 is connected with the second input end of the first adder 8, the output end of the first adder 8 is connected with the bias end of the electro-optical intensity modulator 3, the modulation output end of the phase-locked amplifier 6 is connected with the first input end of a second adder 10, the first output end of a digital delay pulse generator 11 is connected with the second input end of the second adder 10, the output end of the second adder 10 is connected with the output end of the digital delay pulse generator 11 of the single photon generator 5.
The electro-optical intensity modulator used in the embodiment of the invention is an intensity modulator with a Mach-Zehnder interferometer structure, and the relative phases of two waveguide arms are adjusted by changing external voltage based on the electro-optical effect of a lithium niobate crystal so as to realize laser intensity modulation. Under classical light intensity, the corresponding transmitted light intensities of the electro-optical intensity modulator under different bias voltages are sequentially measured by using a direct-current power supply and a photoelectric detector to obtain a transmission curve graph of the electro-optical intensity modulator, and as shown in fig. 2, the transmission curve randomly drifts due to factors such as environmental disturbance, instrument aging and the like, so that a minimum bias point needs to be locked in real time.
The method for rapidly locking the minimum bias point of the electro-optical intensity modulator by using the system comprises the following steps:
the laser 1 outputs 1550nm linear polarization classical laser signals transmitted along the polarization-maintaining optical fiber slow axis, the laser signals enter the attenuator 2 to reduce the intensity to a single photon level, namely the average photon number in each detection gate of the corresponding single photon detector 5 is about 0.1, and then the single photon signals are transmitted along the polarization-maintaining optical fiber slow axis to enter the electro-optical intensity modulator 3 to be modulated.
The signal generator 7 outputs a 10Hz triangular wave scanning signal to be loaded to the bias end of the electro-optic intensity modulator 3 through the first adder 8 so as to carry out linear scanning near the minimum bias point, the modulation end of the phase-locked amplifier 6 outputs an 8kHz sine wave signal to be loaded to the radio frequency end of the electro-optic intensity modulator 3 through the second adder 10 so as to quickly modulate the distribution probability of the single photon signal, the digital delay pulse generator 11 outputs a TTL pulse with the frequency of 4MHz to be loaded to the radio frequency end of the electro-optic intensity modulator 3 through the second adder 10 so as to cut continuous light into 4MHz single photon pulse light, the modulated single photon pulse is transmitted into the optical fiber coupler 4 along the polarization maintaining optical fiber slow axis (the spectral ratio of 50:50) to be divided into two single photon pulses with equal intensity, one single photon pulse is used for scientific research, the other single photon pulse is detected by the single photon detector 5, the digital delay pulse generator 11 outputs another TTL pulse with the frequency of 4MHz as a trigger clock of the single photon detector 5, the time interval between the two pulses is adjusted so that the single photon pulse and the single photon pulse detector 5 is aligned with the single photon detector 5, and the single photon pulse signal is acquired by the single photon detector 5, and the phase-locked amplifier 6 is amplified.
The phase-locked amplifier 6 demodulates the modulated TTL signal, that is, the TTL signal and the co-frequency modulated signal are mixed and subjected to low-pass filtering, so as to obtain an error signal for locking the minimum offset point, the integral time of the phase-locked amplifier 6 is adjusted to be 3ms, the sensitivity is adjusted to be 50mV, the filtering slope is adjusted to be 12dB, the phase of the sine wave modulated signal is changed, the signal-to-noise ratio of the error signal is maximally 39, as shown in fig. 3, the central position of the error signal corresponds to the minimum offset point of the transmission curve, and the error signal is used for tracking and locking the minimum offset point in real time.
The error signal is optimized by the analog proportional-integral-differential controller 9 and then is loaded to the bias end of the electro-optic intensity modulator 3 by the first adder 8, the triangular wave scanning signal output by the signal generator 7 is switched into direct current voltage, the voltage amplitude and the parameters of the analog proportional-integral-differential controller 9 are regulated, the amplitude of the error signal is enabled to be minimum, the error signal realizes the real-time locking of the minimum bias point of the electro-optic intensity modulator 3 by continuously tuning the bias voltage, and the extinction ratio of single photon pulses output within 1000s is larger than 27dB.
According to the embodiment of the invention, the electro-optical intensity modulator is utilized to obtain the error signal corresponding to the transmission curve by periodically modulating the single photon signal distribution probability and demodulating the corresponding TTL signal with the same frequency, and the error signal is used for continuously tuning the bias voltage to lock the minimum bias point of the transmission curve in real time, so that the long-time high extinction ratio single photon pulse output is obtained.
In a word, the invention provides a novel system and a novel method for directly and rapidly locking the minimum bias point of the electro-optic intensity modulator at single photon intensity, so that single photon pulse output with long-time high extinction ratio is obtained, and the locking system is simple, high in locking precision and high in stability, and can be applied to the fields of quantum communication, optical sensing and the like.
It should be noted that modifications and applications can be made by those skilled in the art without departing from the principles of the invention, which are also considered as being within the scope of the invention.
Claims (2)
1. A system for rapidly locking a minimum bias point of an electro-optic intensity modulator, comprising: the device comprises a laser (1), an attenuator (2), an electro-optical intensity modulator (3), an optical fiber coupler (4), a single photon detector (5), a phase-locked amplifier (6), a signal generator (7), a first adder (8), an analog proportional-integral-differential controller (9), a second adder (10) and a digital delay pulse generator (11);
the laser device (1) outputs 1550nm linear polarization laser signals transmitted along a polarization maintaining optical fiber slow axis, the laser signals enter an attenuator (2) to reduce the intensity to a single photon magnitude and then enter an electro-optic intensity modulator (3), the output end of the electro-optic intensity modulator (3) is connected with the input end of an optical fiber coupler (4), the first output end of the optical fiber coupler (4) serves as a signal output end, the second output end of the optical fiber coupler (4) is connected with the input end of a single photon detector (5), the output end of the single photon detector (5) is connected with the input end of a phase-locked amplifier (6), the output end of the phase-locked amplifier (6) is connected with the input end of an analog proportional integral derivative controller (9), the output end of the signal generator (7) is connected with the first input end of a first adder (8), the output end of the analog proportional integral derivative controller (9) is connected with the second input end of the first adder (8), the output end of the first adder (8) is connected with the output end of the second adder (10), the output end of the second adder (10) is connected with the output end of the second adder (10) of the pulse modulator (10), the second output end of the digital delay pulse generator (11) is connected with the trigger end of the single photon detector (5).
2. A method for rapidly locking a minimum bias point of an electro-optic intensity modulator, comprising: the method is based on the system implementation of the minimum bias point of the fast locking electro-optic intensity modulator of claim 1;
the laser (1) outputs linear polarization laser signals transmitted along the slow axis of the polarization maintaining optical fiber, the laser signals enter the attenuator (2) to reduce the intensity to a single photon level, and the single photon signals are transmitted along the slow axis of the polarization maintaining optical fiber and enter the electro-optic intensity modulator (3) to be modulated;
the triangular wave scanning signal output by the signal generator (7) is loaded to the bias end of the electro-optic intensity modulator (3) through the first adder (8); the modulation end of the lock-in amplifier (6) outputs a high-frequency sine wave signal, and the high-frequency sine wave signal is loaded to the radio frequency end of the electro-optic intensity modulator (3) through a second adder (10); the digital delay pulse generator (11) outputs one path of TTL pulse and loads the TTL pulse to the radio frequency end of the electro-optic intensity modulator (3) through the second adder (10), the digital delay pulse generator is used for chopping continuous light into single photon pulse light, the modulated single photon pulse is transmitted into the optical fiber coupler (4) along the polarization maintaining optical fiber slow axis and is divided into two beams, one beam of single photon pulse is output, the other beam of single photon pulse is detected by the single photon detector (5), the digital delay pulse generator (11) outputs the other path of TTL pulse as a trigger clock of the single photon detector (5), the time interval of the two paths of TTL pulse is regulated to enable photon count acquired by the single photon detector (5) to be maximum, and the single photon pulse light is converted into a TTL signal by the single photon detector (5) and is input into the lock-phase amplifier (6);
the phase-locked amplifier (6) demodulates the modulated TTL signal to obtain an error signal for locking a minimum offset point, adjusts the integration time, sensitivity, filtering slope and phase of the modulated signal of the phase-locked amplifier (6) to maximize the signal-to-noise ratio of the error signal, and the central position of the error signal corresponds to the minimum offset point of the transmission curve, wherein the error signal is used for tracking and locking the minimum offset point in real time;
the error signal is loaded to the bias end of the electro-optic intensity modulator (3) through a first adder (8) after being optimized by the analog proportional-integral-derivative controller (9), the triangular wave scanning signal output by the signal generator (7) is switched into direct current voltage, the voltage amplitude and the parameters of the analog proportional-integral-derivative controller (9) are adjusted, the amplitude of the error signal is enabled to be minimum, the error signal achieves real-time locking of the minimum bias point of the electro-optic intensity modulator (3) through continuous tuning of the bias voltage, and single photon pulse output with high extinction ratio is obtained.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9496962B1 (en) * | 2013-06-27 | 2016-11-15 | Clariphy Communications, Inc. | Systems and methods for biasing optical modulating devices |
| CN109193323A (en) * | 2018-11-16 | 2019-01-11 | 忻州师范学院 | Lock the device and method of optical communicating waveband twin-laser frequency |
| CN110146162A (en) * | 2019-06-21 | 2019-08-20 | 忻州师范学院 | The device and method of real-time lock single photon intensity |
| CN211579977U (en) * | 2020-04-17 | 2020-09-25 | 忻州师范学院 | System for fast locking minimum bias point of electro-optical intensity modulator |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US7184671B2 (en) * | 2003-09-16 | 2007-02-27 | Opnext, Inc. | Optical transmission controller |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9496962B1 (en) * | 2013-06-27 | 2016-11-15 | Clariphy Communications, Inc. | Systems and methods for biasing optical modulating devices |
| CN109193323A (en) * | 2018-11-16 | 2019-01-11 | 忻州师范学院 | Lock the device and method of optical communicating waveband twin-laser frequency |
| CN110146162A (en) * | 2019-06-21 | 2019-08-20 | 忻州师范学院 | The device and method of real-time lock single photon intensity |
| CN211579977U (en) * | 2020-04-17 | 2020-09-25 | 忻州师范学院 | System for fast locking minimum bias point of electro-optical intensity modulator |
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