CN108181627B - All-fiber bidirectional mode-locking femtosecond laser ranging device and method based on time domain scanning - Google Patents
All-fiber bidirectional mode-locking femtosecond laser ranging device and method based on time domain scanning Download PDFInfo
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Abstract
The invention relates to an all-fiber bidirectional mode-locking femtosecond laser ranging device and method based on time domain scanning, and belongs to the field of laser ranging. A forward pulse emitted by a light source is divided into a beam of reference light pulse and a beam of measuring light pulse through a Michelson interference unit; the reverse pulse emitted by the light source scans the reference light pulse and the measuring light pulse emitted by the Michelson interference unit through the pulse scanning unit to generate a ranging signal; the data acquisition and processing device can obtain the distance value to be measured according to the ranging signal and the repetition frequency value measured by the frequency counter. Compared with a double-optical comb distance measuring device, the device uses a laser device for generating bidirectional pulses to replace a double-optical comb, the repetition frequency does not need to be adjusted, the measuring structure is optimized, measuring auxiliary equipment is greatly reduced, the size of the distance measuring device is reduced, the cost is saved, and the stability is improved.
Description
Technical Field
The invention relates to an all-fiber bidirectional mode-locking femtosecond laser ranging device and method based on time domain scanning, and belongs to the field of laser ranging.
Background
Typical distance measurements are generally divided into two methods. The first method is a time-of-flight method. The principle of the time-of-flight method is achieved by measuring the round-trip time interval of the pulses. The time-of-flight method has the advantage of wide distance measurement range, and generally can measure several meters to hundreds of kilometers, but the time resolution of the detector can only reach picosecond magnitude, so the measurement accuracy and resolution are limited. The second method is laser interferometry. The laser interferometry uses a continuous laser as a light source, determines the amount of distance change by measuring the number of shifts of the fringes, and thus has a resolution of sub-wavelength. Through the stripe subdivision technology, the resolution can reach dozens of nanometers; however, since the displacement measurement between two points requires continuous movement of the measurement target, it is susceptible to external environment and causes a break point, and thus it is not suitable for absolute distance measurement.
Femtosecond pulsed laser has the characteristics of broad spectrum, narrow pulse, etc., the femtosecond pulses in the time domain are a series of stable, equally spaced pulse trains, while the femtosecond pulses in the frequency domain can provide a series of equally spaced frequency distributions from the microwave frequency to the optical frequency. The repetition frequency and the carrier envelope phase of the femtosecond pulse are simultaneously locked to a high-stability external reference rubidium clock, so that the stability of the femtosecond pulse on a time domain and a frequency domain is greatly improved. With these advantages, high-precision absolute distance measurement can be achieved.
In 2009, Coddington et al achieved 3 μm ranging accuracy at a 5kHz update rate over a 1.5m range using two phase locked femtosecond optical frequency combs. The method has the characteristics of high measuring speed, high measuring precision and large measuring range, but the positions of the double combs are required to be changed for expanding the measuring range, so that the operation is troublesome; in 2010, Lee et al used the femtosecond pulse time flight method of the balanced optical cross-correlation technique, the measurement range of which reached 0.7km, the allen variance reached 117nm at a sampling time of 5ms, and the allen variance decreased to 7nm as the average time increased to 1 s. The method has simple post-processing, high precision and no limit of periodical uncertainty and coherence in the measured distance. For a certain distance to be measured, the method needs to lock two repetition frequencies in phase, and the adjustment range of the repetition frequencies is limited, so the method is not suitable for short-distance measurement and has a measurement dead zone. In 2014, Liyan of Qinghua university and the like propose a nonlinear asynchronous optical sampling absolute distance measurement method based on double optical combs. In the experiment, two optical frequency combs with slightly different repetition frequencies are used for realizing time domain optical scanning, and a frequency doubling technology based on second-class phase matching is used for realizing extraction of peak values so as to obtain flight time. The standard deviation was 1.48 μm when the average time was 0.5ms, and 82.9nm when the average time was 500 ms.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide an all-fiber bidirectional mode-locked femtosecond laser ranging device and method based on time domain scanning.
In order to achieve the purpose, the invention adopts the technical scheme that:
all-fiber two-way mode-locking femtosecond laser ranging device based on time domain scanning comprises a light source, an optical measuring device and a data acquisition and processing device.
The optical measuring device consists of a Michelson interference unit and a pulse scanning unit;
a forward pulse emitted by a light source is divided into a beam of reference light pulse and a beam of measuring light pulse through a Michelson interference unit; the reverse pulse emitted by the light source scans the reference light pulse and the measuring light pulse emitted by the Michelson interference unit through the pulse scanning unit to generate a ranging signal; the data acquisition and processing device can obtain the distance value to be measured according to the ranging signal and the repetition frequency value measured by the frequency counter.
The pulse scanning unit includes: a second half wave plate 13, a third half wave plate 10, a second polarization splitting prism 14, a first convex lens 15, a second convex lens 17, a second-class matching frequency doubling crystal 16 and a dichroic mirror 18; the second half-wave plate 13 and the third half-wave plate 10 are used for adjusting the polarization angle of linearly polarized light. The combined beam light of the reference light pulse and the measurement light pulse generated by the michelson interference unit is incident to the second polarization beam splitter prism 14 through the third half-wave plate 10, and is converged with the reverse pulse emitted by the light source at the second polarization beam splitter prism 14 to obtain a converged beam; the converged light beam sequentially passes through a first convex lens 15, a second type matching frequency doubling crystal 16, a second convex lens 17 and a dichroic mirror 18 and then is collected and processed by a data collecting and processing device;
the light source is a free-running all-fiber bidirectional passive mode-locked annular femtosecond laser;
the Michelson interference unit comprises: the device comprises a first one-half wave plate 3, a first polarization splitting prism 6, a first one-quarter wave plate 5, a second one-quarter wave plate 7, a reflector 4, a beam expander 8 and a pyramid reflector 9. After passing through the first half-wave plate 3, the forward pulse emitted by the light source is divided into two beams of light with vertical polarization at the first polarization beam splitter prism 6. The first one-half wave plate 3 is used for adjusting the polarization state of the light pulse emitted by the light source so as to change the intensity ratio of the two polarized vertical lights separated by the first polarization splitting prism 6. The light enters the reflecting mirror 4 after passing through the first quarter-wave plate 5 and is reflected to be used as reference light pulse; and the other beam is expanded by the second quarter-wave plate 7 and the beam expander 8, enters the pyramid reflecting mirror 9 and is reflected to be used as a measuring light pulse. The effect of the first and second quarter-wave plates 5, 7 is to rotate the polarization of the returning reference light pulses and the measuring light pulses by 90 °. The two reflected return lights are merged at the first polarization splitting prism 6.
The light source is a free-running all-fiber bidirectional passive mode-locked annular femtosecond laser. In general, passive mode-locked fiber lasers employ optical isolators to reduce stray cavity reflections and lower the self-start mode-locking threshold. The all-fiber bidirectional passive mode-locking annular femtosecond laser is embedded into an optical fiber connector by using a carbon nano tube/polymer composite material, is used for saturated absorption to realize bidirectional mode locking, and consists of a wavelength division multiplexer, an erbium-doped fiber, an optical coupler, a carbon nano tube, a single-mode fiber and a polarization controller. The laser has no isolator, and can simultaneously generate stable bidirectional mode-locked pulses with small repetition frequency difference, wherein one is positive and the other is negative. The bidirectional pulse is respectively subjected to power amplification and pulse compression through an erbium-doped fiber amplifier and a dispersion compensation fiber.
Since the scanning light pulse has a slight difference in repetition frequency, that is, a slight time difference in time domain, with the reference light pulse and the measurement light pulse, the reference light pulse and the measurement light pulse correspond to scanning by the scanning light pulse. The second type of matching frequency doubling crystal 16 is characterized by the fact that when two beams of light with perpendicular polarization are incident into the frequency doubling crystal and the two light pulses coincide in the time domain, frequency doubled light is generated. The reference light pulse and the scanning light pulse generate a beam of frequency doubling light, and the measuring light pulse and the scanning light pulse generate another beam of frequency doubling light. The two doubled light beams are filtered by the dichroic mirror 18 and detected by the detector as a reference signal and a measurement signal, respectively.
And measuring the repetition frequency value of the bidirectional pulse generated by the light source by using a frequency counter referenced to a rubidium clock, and inputting the value of the repetition frequency into the data acquisition and processing device. And acquiring a distance measurement signal, and obtaining a pulse flight time by using a peak finding technology through links such as data reading, data filtering, peak value searching, peak value optimization, peak value fitting, distance calculation and the like to obtain a distance value to be measured.
Advantageous effects
1. The invention provides an absolute distance measuring method which is high in measuring precision, high in updating speed and free of measuring blind areas.
2. The invention uses a free-running all-fiber bidirectional passive mode-locking annular femtosecond laser, and compared with a double-femtosecond optical comb distance measurement method, the cost is saved and the stability is improved.
3. The invention does not need to lock repetition frequency and offset frequency and adjust repetition frequency, thereby greatly reducing auxiliary measuring equipment and reducing the volume of the distance measuring device.
Drawings
FIG. 1 is a diagram of an all-fiber two-way mode-locked femtosecond laser ranging device based on time domain scanning;
FIG. 2 is a schematic diagram of an all-fiber two-way mode-locked femtosecond laser ranging based on time domain scanning;
FIG. 3 is a schematic diagram of a pulsed time domain scan;
fig. 4 is a ranging signal diagram.
Wherein, 1-the first erbium-doped fiber amplifier, 2-the first dispersion compensation fiber, 3-the first one-half wave plate, 4-reflector, 5-the first one-half wave plate, 6-the first polarization beam splitter prism, 7-the second one-half wave plate, 8-beam expander, 9-pyramid reflector, 10-the third one-half wave plate, 11-the second erbium-doped fiber amplifier, 12-the second dispersion compensation fiber, 13-the second one-half wave plate, 14-the second polarization beam splitter prism, 15-the first convex lens, 16-crystal, 17-the second convex lens, 18-dichroic mirror
Detailed Description
The embodiments of the present invention will be described in detail below with reference to the drawings and examples.
As shown in fig. 1, the all-fiber bidirectional mode-locked femtosecond laser ranging device based on time domain scanning includes a light source, an optical measuring device and a data collecting and processing device.
As shown in FIG. 2, the light source is a free-running all-fiber bidirectional passive mode-locked ring femtosecond laser, which emits bidirectional pulses with a small repetition frequency difference, wherein the repetition frequency of the forward pulses is frIn the reverse directionThe repetition frequency of the pulses is (f)r+Δfr). The forward pulse is subjected to power amplification and pulse compression through an erbium-doped fiber amplifier 1 and a dispersion compensation fiber 2. After passing through the first half wave plate 3, the light pulse is split into two light pulses with vertical polarization at the first polarization beam splitter prism 6. One beam is incident to the reference reflector 4 after passing through the first quarter-wave plate 5 and is used as a reference light pulse; and the other beam is expanded by the second quarter-wave plate 7 and the beam expander 8 and then enters the pyramid reflecting mirror 9 as a measuring light pulse. The two reflected light pulses are converged at the first polarization beam splitter prism 6, pass through the third half wave plate 10, and enter the second polarization beam splitter prism 14. The reverse pulse is subjected to power amplification and pulse compression through a second erbium-doped fiber amplifier 11 and a second dispersion compensation fiber 12, then is converged with the reference optical pulse and the measurement optical pulse at a second polarization beam splitter prism 14, is converged through a first convex lens 15, and is incident to a second-class matching frequency doubling crystal 16.
Fig. 3 is a schematic diagram of pulse time domain scanning. In the time domain, the pulse interval of the positive pulse is 1/frThe pulse interval of the reverse pulse is 1/(f)r+Δfr). Due to the difference in repetition frequency of the bidirectional pulses, the bidirectional pulses in one-to-one correspondence have a certain time interval. Corresponding to reverse pulse at time interval Δ TrSweeping a positive going pulse. The interval Delta TrIs composed of
Wherein f isrThe repetition frequency of the positive pulse, (f)r+Δfr) For repetition frequency of the reverse pulse, Δ frThe frequency difference is repeated for the bi-directional pulses.
The second-type matching frequency doubling crystal 16 is a BBO (barium metaborate) crystal with a thickness of 2mm, and is characterized in that when two beams of light with vertical polarization are incident into the frequency doubling crystal and two beams of light pulses are superposed on a time domain, frequency doubling light is generated. The bi-directional pulse appears in the time domain as Δ TrFor time domain scanning of step size, coincidence frequency is Δ frTherefore, the frequency of the generated frequency-doubled light is Δ fr. That is to say every 1/deltafrOne measurement can be completed. The light source in this embodiment is a self-developed all-fiber bidirectional passive mode-locked ring femtosecond laser with a forward pulse repetition frequency of 75.805MHz and a reverse pulse repetition frequency of 75.808MHz, and the above analysis shows that the distance measurement update speed of the device reaches 3 kHz.
The reference light pulse and the scanning light pulse generate a beam of frequency doubling light, and the measuring light pulse and the scanning light pulse generate another beam of frequency doubling light. The two doubled light beams are filtered by the dichroic mirror 18 and detected by the detector as a reference signal and a measurement signal, respectively. The dichroic mirror 18 is made of K9 type synthetic glass with an operating angle of 0 deg., and functions to transmit light of an octave wavelength of 775nm and reflect light of a fundamental frequency of 1550 nm.
As shown in FIG. 4, TrefAs reference signal, TtarTo measure the signal. The fuzzy distance of the method is c/(2 n)gfr)，TrefAnd TtarThe time between is the flight time within the single fuzzy distance, so the total effective pulse flight time taudIs composed of
Wherein, trefIs a reference signal, ttarIs a measurement signal; n is integral multiple of the interval of the positive pulse and is obtained by rough measurement of a common distance meter. In the formula (2), let M ═ fr/ΔfrIs approximately equal to 15000, which means that the time resolution is improved by 15000 times through an optical method, and compared with the traditional time flight method, the method has high measurement precision.
The distance to be measured is
Where c speed of light in vacuum, ngIs the refractive index of air.
And measuring the repetition frequency value of the bidirectional pulse generated by the light source by using a frequency counter referenced to a rubidium clock, and inputting the value of the repetition frequency into the data acquisition and processing device. Collecting ranging signals, obtaining pulse flight time by using a peak finding technology through links such as data reading, data filtering, peak value searching, peak value optimization, peak value fitting, distance calculation and the like, and obtaining a distance value to be measured according to a formula (3).
The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (4)
1. All-fiber two-way mode locking femtosecond laser range unit based on time domain scanning, its characterized in that: the device comprises a light source, an optical measuring device and a data acquisition and processing device;
the optical measuring device consists of a Michelson interference unit and a pulse scanning unit;
a forward pulse emitted by a light source is divided into a beam of reference light pulse and a beam of measuring light pulse through a Michelson interference unit; the reverse pulse emitted by the light source scans the reference light pulse and the measuring light pulse emitted by the Michelson interference unit through the pulse scanning unit to generate a ranging signal; the data acquisition and processing device can obtain the distance value to be measured according to the ranging signal and the repetition frequency value measured by the frequency counter.
2. The all-fiber two-way mode-locked femtosecond laser ranging device based on time domain scanning as claimed in claim 1, wherein: the pulse scanning unit includes: the second half wave plate, the third half wave plate, the second polarization beam splitter prism, the first convex lens, the second type matching frequency doubling crystal and the dichroic mirror; the combined beam light of the reference light pulse and the measurement light pulse generated by the Michelson interference unit is incident to a second polarization beam splitter prism through a third half-wave plate, and is converged with the reverse pulse emitted by the light source at the second polarization beam splitter prism to obtain a converged light beam; the converged light beams sequentially pass through the first convex lens, the second type matching frequency doubling crystal, the second convex lens and the dichroic mirror and are collected and processed by the data collecting and processing device.
3. The all-fiber two-way mode-locked femtosecond laser ranging device based on time domain scanning as claimed in claim 1, wherein: the light source is a free-running all-fiber bidirectional passive mode-locked annular femtosecond laser.
4. The all-fiber two-way mode-locked femtosecond laser ranging device based on time domain scanning as claimed in claim 1 or 2, wherein: the Michelson interference unit comprises: the device comprises a first quarter wave plate, a first polarization splitting prism, a first quarter wave plate, a second quarter wave plate, a reflector, a beam expander and a pyramid reflector; after passing through the first half wave plate, the forward pulse emitted by the light source is divided into two beams of light with vertical polarization at the first polarization beam splitter prism; the light enters the reflector after passing through the first quarter-wave plate and is reflected to be used as reference light pulse; and the other beam is expanded by the second quarter-wave plate and the beam expander, enters the pyramid reflecting mirror and is reflected to be used as a measuring light pulse.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003255046A (en) * | 2002-03-04 | 2003-09-10 | Nikon Geotecs Co Ltd | Distance measuring equipment and method |
| CN202583052U (en) * | 2012-05-15 | 2012-12-05 | 中国科学院工程热物理研究所 | Double-color femtosecond laser collinear pumping detection heat reflection device |
| CN105446120A (en) * | 2015-11-25 | 2016-03-30 | 天津大学 | Optical fiber link time-frequency distribution device based on femtosecond laser and stabilizing method thereof |
| CN106289499A (en) * | 2016-07-18 | 2017-01-04 | 中国航空工业集团公司北京长城计量测试技术研究所 | A kind of micrometer vibrational system utilizing femtosecond laser and micrometer method for oscillating |
-
2018
- 2018-01-09 CN CN201810017962.6A patent/CN108181627B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003255046A (en) * | 2002-03-04 | 2003-09-10 | Nikon Geotecs Co Ltd | Distance measuring equipment and method |
| CN202583052U (en) * | 2012-05-15 | 2012-12-05 | 中国科学院工程热物理研究所 | Double-color femtosecond laser collinear pumping detection heat reflection device |
| CN105446120A (en) * | 2015-11-25 | 2016-03-30 | 天津大学 | Optical fiber link time-frequency distribution device based on femtosecond laser and stabilizing method thereof |
| CN106289499A (en) * | 2016-07-18 | 2017-01-04 | 中国航空工业集团公司北京长城计量测试技术研究所 | A kind of micrometer vibrational system utilizing femtosecond laser and micrometer method for oscillating |
Non-Patent Citations (1)
| Title |
|---|
| 双飞秒激光测距系统的测量精度分析;梁飞;《光电子·激光》;20150831;第1553-1560页 * |
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