CN100520281C - Adjustable frequency difference two-frequency laser back-feed nano measuring ruler for frequency stabilizing - Google Patents
Adjustable frequency difference two-frequency laser back-feed nano measuring ruler for frequency stabilizing Download PDFInfo
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- CN100520281C CN100520281C CNB200710176051XA CN200710176051A CN100520281C CN 100520281 C CN100520281 C CN 100520281C CN B200710176051X A CNB200710176051X A CN B200710176051XA CN 200710176051 A CN200710176051 A CN 200710176051A CN 100520281 C CN100520281 C CN 100520281C
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Abstract
The nanometer measuring tape comprises a light source, a probe and a target mirror. The light source uses a frequency-stabilized dual-frequency helium-neon laser; the outputted frequency difference of said dual-frequency laser can to continuously tuned from 1MHz to hundreds MHz; when the target mirror or the measured object moves each 1/8 optical wavelength along with the surface of the measured target, the polarization state of light outputted from the light source varies once. In the range of one cycle from the traceable source to the natural reference, four different polarization states are sequentially appeared, which are parallel ray independent oscillation, parallel ray and vertical ray commonly oscillation, vertical ray independent oscillation and non oscillation; based on the four different polarization states, estimating the bias size and direction of the measured object.
Description
Technical field
The adjustable two-frequency laser back-feed nano of frequency difference that the present invention relates to a kind of frequency stabilization is surveyed chi, belongs to the laser measuring technique field.
Background technology
Laser feedback effect (claiming self-mixing interference effect again) is a kind of basic effect in the laser physics, its fundamental point is: the light beam of laser instrument output is by in the reflective surface reflects back chamber outside the resonator cavity, with the stack of light field in the chamber, thereby physical quantitys such as the output intensity of laser instrument, power, phase place are modulated.The laser feedback effect after being found by people such as King in 1963, and domestic and international research person are devoted to eliminate the influence of this effect to output characteristic of laser, because the existence of this " noise " makes the frequency-stabilizing method of existing laser instrument lose efficacy.
Along with going deep into of research, researchers find that the laser feedback effect has identical depth of modulation and phse sensitivity with traditional two-beam interference effect.Particularly, when the reflecting surface outside the resonator cavity during along the laser axis displacement, the variation that the output intensity of laser instrument can generating period has comprised the information such as size and Orientation of reflecting surface displacement in this variation, by processing of circuit, just can realize displacement measurement to reflecting surface.And utilize the laser feedback effect to carry out displacement measurement only to need a passage, than needing two traditional interferometers of interfering passage of reference arm and gage beam, structure is simpler, and cost is cheaper.Therefore, the laser feedback effect by the lot of domestic and foreign scholar's research, develop, be applied to the measurement of physical quantitys such as displacement, speed, vibration, angle.But the frequency stabilization problem in the laser feedback effect, but be that researchers must be in the face of insoluble bottleneck problem always, the frequency stability of feedback system is about s=10
-6, it make the feedback measuring system aspect stable can't with common interferometer (s＜10
-7) be equal to.In addition, aspect the feedback displacement measurement, researchers have generally run into and can't break through diffraction limit 1/2nd optical wavelength, and can't accurately judge the problems such as direction of measured object displacement, and make the feedback displacement Research on Measuring Technology make slow progress.
On the other hand, traditional double-frequency zeeman laser device is exported frequency difference according to the principle of Zeeman effect and generally is no more than 3MHz, and having limited with it is the measuring speed (can not surpass 900mm/s) of the interferometer of light source.By place the birefringence double-frequency laser that birefringence element obtains double frequency output in laser resonant cavity, because mode competition, the output frequency difference can not be less than 40MHz.Therefore, between the 40MHz frequency difference lower limit of the 3MHz of the double-frequency zeeman laser device frequency difference upper limit and birefringence double-frequency laser, a white space is arranged, and this regional frequency difference can satisfy the rate request of quick measurement, can make subsequent process circuit simple again, and its using value is the highest.
Summary of the invention
The present invention combines the advantage of laser feedback effect, Zeeman effect and birefringence effect, and providing a kind of can be light source to continuously adjustable two-frequency laser between the hundreds of MHz at 1MHz with the output frequency difference, and frequency stability is better than 10
-8, resolution 1/8th optical wavelength, and realized can declaring to the back-feed nano of measuring and surveyed chi.
The invention is characterized in that it contains:
The Lights section, be an output frequency difference at 1MHz to the continuously adjustable orhtogonal linear polarizaiton light of hundreds of MHz, through the two-frequency laser of the whole bore type of overheated frequency stabilization, this laser instrument comprises:
Laser gain pipe, in fill the He-Ne combination gas;
The key light outgoing mirror is positioned at the axial side of described laser gain pipe, is flat mirror, and it is towards the inside surface plating reflectance coating of gain tube, outside surface plating anti-reflection film;
Tail light outgoing mirror is positioned at the axial opposite side of described laser gain pipe, is concave mirror, and it is towards the concave surface plating anti-reflection film of gain tube, outside surface plating reflectance coating;
The transverse magnetic field generator, form by two blocks of parallel permanent magnets of both sides, described laser gain pipe axis that place, whole gain tube is in the magnetic field, and magnetic direction is perpendicular to laser axis, and is parallel or perpendicular to the polarization direction of any polarization state of laser instrument output;
The frequency stabilization structure, constitute by close resistance wire and the aluminium shell that is around in helium-neon laser shell (not containing the pipe neck), the thermal effect of energising back resistance wire can be laser instrument and evenly heats, make laser instrument reach thermally-stabilised in the short period of time, aluminium shell is enclosed in a space that temperature is relatively independent with laser tube, thus the frequency of stable laser;
The stress bringing device is used for described outgoing mirror is applied the stress perpendicular to laser axis;
Probe segment, it comprises:
Polarization splitting prism is positioned at the opposite side of described tail light outgoing mirror, is used for laser instrument output light with cross polarization and is split up into orthogonal and two bundles that propagate along different directions in polarization direction;
Photodetector, totally two, be positioned at two surfaces that light beam output is arranged of described Glan prism, the light intensity that are used for detecting the laser beam of the two bundle cross polarizations that Glan prism separates change;
Amplifying circuit, totally two, be positioned at the rear end of above-mentioned photodetector, be used for electric current-voltage transitions and signal processing and amplifying are carried out in the output of photodetector;
The above-mentioned partly integrated of probe is assemblied in independently in the black box, only reserves light beam input end and circuit output end respectively in both sides;
The A/D change-over circuit is gathered the two-way amplifying signal, and is converted into digital signal;
Fpga chip and peripheral circuit thereof are mainly finished shaping, filtering to digital signal, and add floating threshold voltage on signals, finish the computing of the counting and the judgement sense of displacement of subregion segmentation;
Digital indicator is used for the result of displacement measurement is shown;
The black box of above-mentioned the Lights section and the probe part fixed support of respectively hanging oneself is installed on the same base platform;
Target mirror part, it is a catoptron that can be fixed on the testee, described catoptron can be with testee along the displacement of laser instrument main beam exit direction, make the polarized light that incides two on testee bundle quadrature be reflected back toward laserresonator respectively with the chamber in two bundle cross polarization optical superposition, cause the polarized light light-intensity variation separately of two bundle quadratures, the reflectivity range of described catoptron is 0.1%～99.99%, and described catoptron also can be the smooth surface of measured object;
Feature of the present invention also is, it contains:
The Lights section is single longitudinal mode output frequency difference at the two-frequency laser through half external cavity type of oversampling circuit frequency stabilization of 1MHz to the continuously adjustable orhtogonal linear polarizaiton light of hundreds of MHz, and this laser instrument comprises:
Laser gain pipe, in fill the He-Ne combination gas;
Anti-reflection window is positioned at the axial side of described laser gain pipe, is flat mirror, and its surfaces externally and internally all plates anti-reflection film;
The key light outgoing mirror is positioned at the opposite side of described anti-reflection window, is flat mirror, and it is towards inside surface plating reflectance coating of anti-reflection window;
Driver part is the tubular piezo-electric pottery, is consolidated with the outside surface of described key light outgoing mirror, is used to drive outgoing mirror, realizes the harmonious dynamic frequency stabilization of intonation;
Position phase regulator is positioned at the opposite side of described key light outgoing mirror, has an element of phase regulatory function to constitute by wave plate or other, and its function is the phasic difference of adjusting between the polarized light of two bundle quadratures;
Tail light outgoing mirror is positioned at the axial opposite side of described laser gain pipe, is concave mirror, surface plating reflectance coating;
The transverse magnetic field generator, form by two blocks of parallel permanent magnets of both sides, described laser gain pipe axis that place, whole gain tube is in the magnetic field, and magnetic direction is perpendicular to laser axis, and is parallel or perpendicular to the polarization direction of any polarization state of laser instrument output;
The frequency stabilization structure is made up of described driver part and the frequency stabilization circuit that is fixed on the key light outgoing mirror;
The stress bringing device is used for described anti-reflection window is applied the stress perpendicular to laser axis;
Probe segment, it comprises:
Polarization splitting prism is positioned at the opposite side of described tail light outgoing mirror, is used for laser instrument output light with cross polarization and is split up into orthogonal and two bundles that propagate along different directions in polarization direction;
Photodetector, totally two, be positioned at two surfaces that light beam output is arranged of described Glan prism, the light intensity that are used for detecting the laser beam of the two bundle cross polarizations that Glan prism separates change;
Amplifying circuit, totally two, be positioned at the rear end of above-mentioned photodetector, be used for current/voltage-converted and signal processing and amplifying are carried out in the output of photodetector;
The above-mentioned partly integrated of probe is assemblied in independently in the black box, only reserves light beam input end and circuit output end respectively in both sides;
The A/D change-over circuit is gathered the two-way amplifying signal, and is converted into digital signal;
Fpga chip and peripheral circuit thereof are mainly finished shaping, filtering to digital signal, and add floating threshold voltage on signals, finish the computing of the counting and the judgement sense of displacement of subregion segmentation;
Frequency stabilization circuit, be used for the peak point of the two paths of signals of described A/D change-over circuit collection is compared analysis, and export control signal in view of the above and give the D/A change-over circuit, after the PI amplifier amplifies, the driver part of controlling described the Lights section promotes the outgoing mirror motion, realizes the dynamic frequency stabilization to laser instrument;
Digital indicator is used for the result of displacement measurement is shown;
The black box of above-mentioned the Lights section and the probe part fixed support of respectively hanging oneself is installed on the same base platform;
Target mirror part, it is a catoptron that can be fixed on the testee, described catoptron can be with testee along the displacement of laser instrument main beam exit direction, make the polarized light that incides two on testee bundle quadrature be reflected back toward laserresonator respectively with the chamber in two bundle cross polarization optical superposition, cause the polarized light light-intensity variation separately of two bundle quadratures, the reflectivity range of described catoptron is 0.1%～99.99%, and described catoptron also can be the smooth surface of measured object;
The invention provides a kind of frequency stabilization, frequency difference is adjustable, and resolution breaks through diffraction limit, and realization can be declared to the nanometer scale optics survey chi of measuring, and it is small and exquisite, with low cost that this surveys chi volume, and can carry out contactless measurement.
Description of drawings
Fig. 1: the whole bore type birefringence of hot frequency stabilization-double-frequency zeeman laser device back-feed nano is surveyed the chi synoptic diagram.
Fig. 2: the half external cavity type birefringence of circuit frequency stabilization-double-frequency zeeman laser device back-feed nano is surveyed the chi synoptic diagram.
Fig. 3: based on the static frequency stabilization schematic diagram of birefringence-double-frequency zeeman laser device intonation harmonic curve.
Fig. 4: the feedback light intensity curve and the dynamic frequency stabilization point synoptic diagram of two bundle crossed polarized lights in the measuring process.
Fig. 5: add that signal behind the floating threshold voltage carries out subdivision and count and declares to instrumentation plan.
Embodiment
Example one structure of the present invention as shown in Figure 1,2 is the key light outgoing mirror of helium-neon laser, and its reflectivity is 99.5%, and reflectance coating is plated in the right surface of this level crossing, anti-reflection film is plated in the left surface of this level crossing, is full of the mixed gas of He and Ne in the laser gain pipe 3.The left surface plating anti-reflection film of tail light outgoing mirror 7 is concave surface, and right surface plating reflectance coating is the plane, and reflectivity is about 99.8%.2,3 and 7 have formed the helium-neon laser of a whole bore type jointly, and the chamber is long to be 80mm～120mm.After diameter applies an external force 13 on the tail light outgoing mirror 7, because the stress birefrin effect makes laser instrument export two bundle crossed polarized lights: directional light and vertical light.Can adjust two frequency differences of restrainting between the crossed polarized lights by the size of control external force.After diameter on the key light outgoing mirror 2 applies an external force 13,, can artificially control the phasic difference between the two bundle crossed polarized lights by adjusting the external force size.The close aluminium shell 6 that is around in resistance wire 5 on the gain tube 3 and laser tube has constituted the hot frequency stabilization structure of laser instrument jointly, 5 heatings of energising back, laser tube temperature is on every side risen in the short period of time, the output frequency of rapid stable laser, 6 play insulation and thermally equilibrated effect, make the laser instrument after the frequency stabilization be subjected to the influence of ambient temperature fluctuations very little, thereby reach the purpose of long-time frequency stabilization.Place the permanent magnet strip 4 of laser instrument both sides to be installed in above 6, its function is for gain tube 3 provides a transverse magnetic field vertical with laser axis, produces transverse zeeman effect.The course of work that chi is surveyed in the whole bore type birefringence of this hot frequency stabilization-double-frequency zeeman laser device back-feed nano is: when the surface of measured object or target mirror 1 during along the laser axis displacement, the variation of the light intensity meeting generating period of two bundle crossed polarized lights, behind polarization splitting prism 8, two bundle crossed polarized lights are propagated along different directions respectively, and surveyed by photodetector 9 and 12 respectively, after conversion amplification and A/D Acquisition Circuit 10, be admitted to fpga chip and peripheral circuit 11 is analyzed and calculated, the final displacement size and Orientation that on display 14, has demonstrated testee, wherein, if the testee sense of displacement is consistent with the positive dirction of default, then displacement is shown as positive number, otherwise then is negative value.
Principle of the present invention is as follows:
In the helium-neon laser of single-mode oscillation, the two difference on the frequency Δ v and the relations between the external carbuncle F of restrainting between the crossed polarized lights that produced by chamber internal stress birefringence effect satisfy:
In the formula, v is an optical frequency, and L is that laser resonant cavity is long, and λ is an optical wavelength, and D is the diameter of crystal, f
0Be the material fringe value.
Do the time spent as the laser feedback effect, target mirror 1 among Fig. 1 and key light outgoing mirror 2 have constituted a F-P chamber, we are referred to as the feedback exocoel, the effective reflectivity of target mirror 1 can be coupled on the key light outgoing mirror 2, the light intensity of two bundle crossed polarized lights of birefringence at this moment ,-double-frequency zeeman laser device output changes and can be expressed as:
ΔI
1＝I
1-I
01＝c(β
2-θ)(R
f1-R
2)/4ML，
ΔI
2＝I
2-I
02＝c(β
1-θ)(R
f2-R
2)/4ML， (2)
M＝β
1β
2-θ
12θ
21.
In the formula, subscript 1 and 2 is represented directional light and vertical light, I respectively
1And I
2Be respectively directional light and vertical light at the stable state light intensity that has under the laser feedback condition, I
01And I
02Be the two stable state light intensity when the unglazed feedback, β
1And β
2Be saturation parameter, θ
12And θ
21Be mutual saturation coefficient, under three rank perturbation approximations, θ arranged
12=θ
21=θ, c are the light velocity in the vacuum, R
F1And R
F2Be the effective reflectivity of the target mirror 1 equivalent reflectivity after being coupled on the key light outgoing mirror 2, its expression formula is:
(3)
In the formula, R
2And R
3Represent the reflectivity of key light outgoing mirror 2 and target mirror 1 respectively, δ
1And δ
2Be respectively the phasic difference between the adjacent folded light beam of feedback exocoel of directional light and vertical light, δ is arranged between the two
1=δ
2+ 4 π l Δ v/c, wherein l represents the length of feedback exocoel.To can obtain in formula (3) the substitution formula (2)
I
1-I
01＝N(β
2-θ)(1-R
2)×[1-(1-R
3)/(1+R
2R
3+2r
2r
3cosδ
1)]
I
2-I
02＝N(β
1-θ)(1-R
2)×[1-(1-R
3)/(1+R
2R
3+2r
2r
3cosδ
2)]， (4)
N＝c/4ML，
In the formula, r
2And r
3Represent the reflection coefficient of key light outgoing mirror 2 and target mirror 1 respectively.
Device according to above principle and Fig. 1, can obtain feedback light intensity curve Fig. 4 through conversion amplification and A/D Acquisition Circuit 10 backs two bundle crossed polarized lights, transverse axis representative is the target mirror along laser axis time of displacement at the uniform velocity among the figure, what characterize is the displacement of target mirror, what the longitudinal axis was represented is the signal voltage value that collects, what characterize is laser instrument output light intensity, therefore, the physical significance of Fig. 4 is: the periodic wave moving curve that two bundle cross polarization light intensities produce along with the displacement of target mirror, on behalf of the target mirror, the one-period of this curve moved 1/2nd optical wavelength.This physical principle has determined Nano-meter Measurement Ruler of the present invention to have self calibrating function, can not cause the accumulation of error.Fpga chip and peripheral circuit 11 thereof, detect the magnitude of voltage of the point that two bundle polarized light light intensity equate in Fig. 4 signal, two such points are arranged in one-period, the voltage of corresponding 4V of difference and 0V, get phase intermediate value 2V as floating threshold voltage, signal handled obtain curve shown in Figure 5, the polarization state of four kinds of different conditions appears in order among the figure: directional light vibrate separately (AB district), directional light and vertical light vibrate jointly (BC district), vertical light is vibrated separately in (CD district), no light generation (DA district).Therefore, one-period is divided into four parts, and the displacement size of every part representative is 1/8th optical wavelength, thereby has realized that the displacement size breaks through the segmentation of diffraction limit.When target mirror 1 when different directions moves, the order that polarization state occurs is different, by the polarization state change frequency N of record target mirror 1 to the positive dirction motion
+With N to the negative direction motion
-, just can obtain the final mean annual increment movement of target mirror 1:
This result after showing on the display 14, has promptly been finished the process of one-shot measurement.
The structural representation of example two of the present invention as shown in Figure 2,1-4 and 7-14 totally ten two elements are identical with the element of reference numeral among Fig. 1, so locate no longer to repeat to introduce.Position phase regulator 16 in the feedback exocoel, there is an element of phase regulatory function to constitute by wave plate or other, its function is the phasic difference of adjusting between the polarized light of two bundle quadratures, be positioned at after diameter applies an external force 13 on the anti-reflection window 18 of laser resonant cavity, because the stress birefrin effect makes laser instrument export two bundle crossed polarized lights: directional light and vertical light.D/A change-over circuit 15, PI amplifier 16 and piezoelectric ceramics 17 have constituted the frequency stabilization circuit of this example jointly.Its frequency stabilization principle as shown in Figure 3, Fig. 3 does not have under the situation of laser feedback effect, birefringence-double-frequency zeeman laser device intonation harmonic curve, what wherein time shaft characterized is the output frequency of laser instrument, what the laser intensity axle characterized is the laser instrument output intensity, as can be seen from the figure, in the process of the inswept bright dipping bandwidth of laser instrument output frequency, its polarization state has experienced in proper order: have only a district of directional light output, directional light and two districts of vertical light coexistence output and three districts that have only vertical light to export.The desirable output frequency of the birefringence among the present invention-double-frequency zeeman laser device is pairing frequency when directional light is equal with the vertical light output intensity in two districts, the static frequency stabilization point that promptly marks among the figure.Therefore, in the frequency stabilization process, fpga chip and peripheral circuit 11 thereof are at first judged the strength difference between the two bundle crossed polarized lights, and output voltage signal in view of the above, behind D/A change-over circuit 15 and PI amplifier 16, it is humorous that 2 pairs of laser instruments of drive pressure electroceramics 17 and key light outgoing mirror carry out intonation, and the strength difference between two bundle crossed polarized lights is zero, finishes static frequency stabilization process.When beginning to measure, the peak point of the two paths of signals of fpga chip and the collection of 11 pairs of A/D change-over circuits of peripheral circuit thereof carries out real-time comparative analysis, and export control signal in view of the above and give the D/A change-over circuit, after the PI amplifier amplifies, the driver part of controlling described the Lights section promotes the outgoing mirror motion, realization is to the dynamic frequency stabilization of laser instrument, as the dynamic frequency stabilization point that is marked among Fig. 4.The course of work that chi is surveyed in the half external cavity type birefringence of this circuit frequency stabilization-double-frequency zeeman laser device back-feed nano is: when the surface of measured object or target mirror 1 during along the laser axis displacement, the variation of the light intensity meeting generating period of two bundle crossed polarized lights, behind polarization splitting prism 8, two bundle crossed polarized lights are propagated along different directions respectively, and surveyed by photodetector 9 and 12 respectively, after conversion amplification and A/D Acquisition Circuit 10, be admitted to fpga chip and peripheral circuit 11 is analyzed and calculated, the final displacement size and Orientation that on display 14, has demonstrated testee, wherein, if the testee sense of displacement is consistent with the positive dirction of default, then displacement is shown as positive number, otherwise then is negative value.
The two-frequency laser back-feed nano that the frequency difference of the frequency stabilization that the present invention is designed is adjustable is surveyed chi by light source, probe and target mirror three parts Form, anti-interference, volume is little, range is big. Its light source uses is that frequency difference after the frequency stabilization connects between hundreds of MHz at 1MHz Continuous adjustable double frequency He-Ne laser, when the surface of target mirror or measured target along every movement 1/8th optical wavelength of laser axis, Light source output polarisation of light attitude changes once, can judge accordingly the size and Orientation of measured target displacement. At accessories such as photoswitches Auxiliary lower, the designed back-feed nano of the present invention is surveyed chi can also realize real-time online measuring to the length of parts on the production line, Have reliable and stable, the resolution ratio height, fast response time, cost is low, and easily characteristics are installed.
Claims (4)
1, the adjustable two-frequency laser back-feed nano of the frequency difference of frequency stabilization is surveyed chi, and it comprises light source, probe and target mirror three parts, it is characterized in that it contains:
The Lights section, be an output frequency difference at 1MHz to the continuously adjustable orhtogonal linear polarizaiton light of hundreds of MHz, through the two-frequency laser of the whole bore type of overheated frequency stabilization, this laser instrument comprises:
Laser gain pipe, in fill the He-Ne combination gas;
The key light outgoing mirror is positioned at the axial side of described laser gain pipe, is flat mirror, and it is towards the inside surface plating reflectance coating of gain tube, outside surface plating anti-reflection film;
Tail light outgoing mirror is positioned at the axial opposite side of described laser gain pipe, is concave mirror, and it is towards the concave surface plating anti-reflection film of gain tube, outside surface plating reflectance coating;
The transverse magnetic field generator, form by two blocks of parallel permanent magnets of both sides, described laser gain pipe axis that place, whole gain tube is in the magnetic field, and magnetic direction is perpendicular to laser axis, and is parallel or perpendicular to the polarization direction of any polarization state of laser instrument output;
The frequency stabilization structure, constitute by close resistance wire and the aluminium shell that is around in the helium-neon laser shell, the thermal effect of energising back resistance wire can be laser instrument and evenly heats, make laser instrument reach thermally-stabilised in the short period of time, aluminium shell is enclosed in a space that temperature is relatively independent, the frequency of stable laser with laser tube;
The stress bringing device applies the stress perpendicular to laser axis to described outgoing mirror;
Probe segment, it comprises:
Polarization splitting prism is positioned at the opposite side of described tail light outgoing mirror, and the laser instrument output light of cross polarization is split up into orthogonal and two bundles that propagate along different directions in polarization direction;
Photodetector, totally two, be positioned at the opposite side of described polarization splitting prism, the light intensity that detect the laser beam of the two bundle cross polarizations that polarization splitting prism separated change;
Amplifying circuit, totally two, be positioned at the rear end of above-mentioned photodetector, current/voltage-converted and signal processing and amplifying are carried out in the output of photodetector;
The above-mentioned partly integrated of probe is assemblied in independently in the black box, only reserves light beam input end and circuit output end respectively in both sides;
The A/D change-over circuit is gathered the two-way amplifying signal, and is converted into digital signal;
Fpga chip and peripheral circuit thereof are mainly finished shaping, filtering to digital signal, and add floating threshold voltage on signals, finish the computing of the counting and the judgement sense of displacement of subregion segmentation;
Digital indicator shows the result of displacement measurement;
The black box of above-mentioned the Lights section and the probe part fixed support of respectively hanging oneself is installed on the same base platform;
Target mirror part, it is a catoptron that is fixed on the testee, described catoptron with testee along the displacement of laser instrument main beam exit direction, make the polarized light that incides two on testee bundle quadrature be reflected back toward laserresonator respectively with the chamber in two bundle cross polarization optical superposition, cause the polarized light light-intensity variation separately of two bundle quadratures, the reflectivity range of described catoptron is 0.1%～99.99%.
2, Nano-meter Measurement Ruler according to claim 1 is characterized in that, described catoptron is the smooth surface of measured object.
3, the adjustable two-frequency laser back-feed nano of the frequency difference of frequency stabilization is surveyed chi, it is characterized in that it contains:
The Lights section is single longitudinal mode output frequency difference at the two-frequency laser through half external cavity type of oversampling circuit frequency stabilization of 1MHz to the continuously adjustable orhtogonal linear polarizaiton light of hundreds of MHz, and this laser instrument comprises:
Laser gain pipe, in fill the He-Ne combination gas;
Anti-reflection window is positioned at the axial side of described laser gain pipe, is flat mirror, and its surfaces externally and internally all plates anti-reflection film;
The key light outgoing mirror is positioned at the opposite side of described anti-reflection window, is flat mirror, and it is towards inside surface plating reflectance coating of anti-reflection window;
Driver part is the tubular piezo-electric pottery, is consolidated with the outside surface of described key light outgoing mirror, drives outgoing mirror, realizes the harmonious circuit frequency stabilization of intonation;
Position phase regulator is positioned at the opposite side of described key light outgoing mirror, has an element of phase regulatory function to constitute by wave plate or other, and its function is the phasic difference of adjusting between the polarized light of two bundle quadratures;
Tail light outgoing mirror is positioned at the axial opposite side of described laser gain pipe, is concave mirror, surface plating reflectance coating;
The transverse magnetic field generator, form by two blocks of parallel permanent magnets of both sides, described laser gain pipe axis that place, whole gain tube is in the magnetic field, and magnetic direction is perpendicular to laser axis, and is parallel or perpendicular to the polarization direction of any polarization state of laser instrument output;
The frequency stabilization structure is made up of described driver part and the frequency stabilization circuit that is fixed on the key light outgoing mirror;
The stress bringing device applies the stress perpendicular to laser axis to described anti-reflection window;
Probe segment, it comprises:
Polarization splitting prism is positioned at the opposite side of described tail light outgoing mirror, and the laser instrument output light of cross polarization is split up into orthogonal and two bundles that propagate along different directions in polarization direction;
Photodetector, totally two, be positioned at the opposite side of described polarization splitting prism, the light intensity that detect the laser beam of the two bundle cross polarizations that polarization splitting prism separated change;
Amplifying circuit, totally two, be positioned at the rear end of described photodetector, current/voltage-converted and signal processing and amplifying are carried out in the output of photodetector;
The above-mentioned partly integrated of probe is assemblied in independently in the black box, only reserves light beam input end and circuit output end respectively in both sides;
The A/D change-over circuit is gathered the two-way amplifying signal, and is converted into digital signal;
Fpga chip and peripheral circuit thereof are mainly finished shaping, filtering to digital signal, and add floating threshold voltage on signals, finish the computing of the counting and the judgement sense of displacement of subregion segmentation;
Frequency stabilization circuit, be used for the peak point of the two paths of signals of described A/D change-over circuit collection is compared analysis, and export control signal in view of the above and give the D/A change-over circuit, after the PI amplifier amplifies, the driver part of controlling described the Lights section promotes the outgoing mirror motion, realizes the dynamic frequency stabilization to laser instrument;
Digital indicator shows the result of displacement measurement;
The black box of above-mentioned the Lights section and the probe part fixed support of respectively hanging oneself is installed on the same base platform;
Target mirror part, it is a catoptron that is fixed on the testee, described catoptron can be with testee along the displacement of laser instrument main beam exit direction, make the polarized light that incides two on testee bundle quadrature be reflected back toward laserresonator respectively with the chamber in two bundle cross polarization optical superposition, cause the polarized light light-intensity variation separately of two bundle quadratures, the reflectivity range of described catoptron is 0.1%～99.99%.
4, Nano-meter Measurement Ruler according to claim 3 is characterized in that, described catoptron is the smooth surface of measured object.
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| CNB200710176051XA CN100520281C (en) | 2007-10-18 | 2007-10-18 | Adjustable frequency difference two-frequency laser back-feed nano measuring ruler for frequency stabilizing |
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| CN103018747A (en) * | 2012-11-26 | 2013-04-03 | 中国人民解放军第四军医大学 | Laser self-mixing distance measuring system based on uncollimated feedback external cavity |
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| CN103115573B (en) * | 2013-01-30 | 2015-08-12 | 清华大学 | Displacement measurement method |
| CN103464959A (en) * | 2013-09-11 | 2013-12-25 | 奇昊汽车系统（苏州）有限公司 | Cross car beam (CCB) welding device with protection function |
| CN104034264B (en) * | 2014-06-14 | 2017-02-15 | 哈尔滨工业大学 | Traceable accurate measurement ruler based semiconductor laser distance measurement device and method |
| CN106524898B (en) * | 2016-11-21 | 2019-12-13 | 北京镭测科技有限公司 | Frequency stabilizing device and method for output frequency difference of double-frequency laser |
| CN109444004B (en) * | 2018-12-14 | 2021-05-18 | 西安理工大学 | Yb-YAG solid laser self-mixing interference nano-grain size sensor |
| CN111256583B (en) * | 2020-02-03 | 2021-09-21 | 暨南大学 | Differential self-mixing interference measurement system and method |
| CN111786255B (en) * | 2020-08-04 | 2024-04-19 | 中国工程物理研究院总体工程研究所 | Frequency-stabilizing and light-stabilizing intensity double-piezoelectric ceramic tuning external cavity semiconductor laser |
-
2007
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Non-Patent Citations (2)
| Title |
|---|
| 激光器纳米测尺原理. 张书练.中国工程科学，第7卷第3期. 2005 |
| 激光器纳米测尺原理. 张书练.中国工程科学，第7卷第3期. 2005 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103018747A (en) * | 2012-11-26 | 2013-04-03 | 中国人民解放军第四军医大学 | Laser self-mixing distance measuring system based on uncollimated feedback external cavity |
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