CN102570273A - Double-frequency laser device - Google Patents
Double-frequency laser device Download PDFInfo
- Publication number
- CN102570273A CN102570273A CN2010106192863A CN201010619286A CN102570273A CN 102570273 A CN102570273 A CN 102570273A CN 2010106192863 A CN2010106192863 A CN 2010106192863A CN 201010619286 A CN201010619286 A CN 201010619286A CN 102570273 A CN102570273 A CN 102570273A
- Authority
- CN
- China
- Prior art keywords
- frequency
- acousto
- light
- optical device
- laser
- 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.)
- Pending
Links
Images
Landscapes
- Instruments For Measurement Of Length By Optical Means (AREA)
Abstract
A double-frequency laser device comprises a single-frequency laser device, a first Wollaston prism, a first driver, a first acousto-optic device, a second driver, a second acousto-optic device, a second Wollaston prism and a beam expander. The first driver sends a first drive signal with frequency fs1 to the first acousto-optic device, and the second driver sends a second drive signal with frequency fs2 to the second acousto-optic device so as to enable the first acousto-optic device and the second acousto-optic device to respectively form a Bragg grating. The single-frequency laser device sends laser with frequency f0, and the laser is divided by the first Wollaston prism into P polarized light and S polarized light which are perpendicular to each other in polarization state. The P polarized light enters the first acousto-optic device at a positive Bragg angle to output light with frequency f0+fs1. The S polarized light enters the first acousto-optic device at a negative Bragg angle to output light with frequency f0-fs1 and then enters the second acousto-optic device at a positive Bragg angle to output light with frequency f0-fs1+fs2. Two beams of light are merged in the second Wollaston prism and then output through the beam expander, and the frequency difference of output light is 2(fs1-fs2).
Description
Technical field
The present invention relates to laser technology field, relate in particular to a kind of two-frequency laser.
Background technology
Two-frequency laser can be used for the double-frequency laser interferometry field, measures such as ultraprecise phase place and displacement measurement, optical element and blooming, the research that also can be used for forming the two-frequency laser array or be used for communication optical fiber etc.
The method that produces double-frequency laser at present mainly contains Zeeman splitting technology harmony light modulation techniques.
Adopt the two-frequency laser of Zeeman splitting technology very ripe, have ripe product.But adopt the two-frequency laser of Zeeman splitting technology all to have a common shortcoming: frequency difference generally is no more than 4.0MHz, and this can not satisfy the increasingly high ultraprecise displacement measurement of measuring speed.As everyone knows; The maximum detection amount speed of double-frequency laser interferometry system and the output frequency difference of two-frequency laser are directly proportional; Such as highest measurement speed is 1m/s, adopts the interferometer of 4 times of segmentations to measure, and requires two-frequency laser output frequency difference 6.3MHz at least.Therefore, adopt the two-frequency laser of Zeeman splitting technology can't satisfy measurement at a high speed.
Opposite with the two-frequency laser of Zeeman splitting, adopt the two-frequency laser of acoustooptic modulation technology, its output frequency difference is then too big, is generally tens MHz, and this mainly is that characteristic by the acousto-optic frequency shifter determines.This frequency difference up to tens MHz brings very big difficulty can for the processing of circuit system, needs special Circuits System to handle, and has increased the difficulty and the cost of Circuits System greatly.For the double-frequency laser interferometry system, only frequency difference will be 3MHz～15MHz, even according to the measurement demand, and it is adjustable to carry out frequency difference.
Summary of the invention
The object of the present invention is to provide a kind of two-frequency laser, wherein, used two acousto-optic frequency shifters of series connection each other, single-frequency laser is modulated, and the final orthogonal double-frequency laser of output polarization attitude, its frequency difference is adjustable within a large range.
According to a kind of two-frequency laser of the present invention, comprise single frequency laser, first wollaston prism, first driver, first acousto-optical device, second driver, rising tone optical device, second wollaston prism and beam expanding lens; Said first driver sends first drive signal that frequency is fs1 to said first acousto-optical device; Said second driver sends second drive signal that frequency is fs2 to said rising tone optical device, makes said first and second acousto-optical devices form a Bragg grating respectively; The frequency that said single frequency laser sends is that the laser of f0 is divided into orthogonal P polarised light of polarization state and S polarised light via said first wollaston prism; The P polarised light is incident to said first acousto-optical device with positive Bragg angle, and output frequency is the light of f0+fs1, and then is incident to said rising tone optical device with negative Bragg angle, and output frequency is the light of f0+fs1-fs2; The S polarised light is incident to said first acousto-optical device with negative Bragg angle, and output frequency is the light of f0-fs1, and then is incident to said rising tone optical device with positive Bragg angle, and output frequency is the light of f0-fs1+fs2; Two-beam closes Shu Houjing and is exported by said beam expanding lens in said second wollaston prism, the difference of output light frequency is 2 (f
S1-f
S2).
Wherein, it is characterized in that the frequency adjustable of the drive signal of said first driver or the output of said second driver.
Wherein, it is characterized in that, when said single frequency laser polarization light output, put a quarter-wave plate in said first wollaston prism the place ahead.
Wherein, said single frequency laser is a stabilized single-frequency laser.
Wherein, at top speed the light beam that sends of single frequency laser transmit through light-conductive optic fibre.
Two wollaston prisms of the present invention, two acousto-optic frequency shifters and a beam expanding lens are formed modulation module jointly.The light beam of single frequency laser output can be transported to modulation module through light-conductive optic fibre.Therefore in use, can be placed on place by the single frequency laser that caloric value is big, only need all very little modulation module of quality of regulation and caloric value, have advantage easy to use away from measured zone.
Two-frequency laser of the present invention has the following advantages: 1. the output frequency difference is moderate, adjustable; 2. modulation module separates with laser, is convenient to regulate; 3. can the heat of laser not introduced measured zone, be convenient to improve the certainty of measurement of interferometer measuration system.Therefore can be used as the perfect light source of double-frequency laser interferometry system.
Description of drawings
Through the embodiment of the invention and combine the description of its accompanying drawing, can further understand purpose, specific structural features and the advantage of its invention.Wherein, accompanying drawing is:
Shown in Figure 1 is Prague acoustooptic diffraction principle;
Shown in Figure 2 is the structural representation of laser according to an embodiment of the invention.
Embodiment
Below, describe in detail according to a preferred embodiment of the invention in conjunction with accompanying drawing.For the ease of describing and the outstanding the present invention of demonstration, omitted existing associated components in the prior art in the accompanying drawing, and will omit description these well-known components.
As everyone knows, when ultrasonic wave passed medium, produce periodically elastic deformation within it, thereby make the refractive index of medium produce cyclic variation, be equivalent to a mobile phase grating, be called acoustooptical effect.If have light to pass medium simultaneously, light will be called acoustooptic diffraction by phase grating institute diffraction.The device that utilizes the acoustooptic diffraction effect to process is called acousto-optical device.Acousto-optical device can fast and effeciently be controlled intensity of laser beam, direction and frequency.
As shown in Figure 1, when incident light during, can produce Bragg diffraction with a special angle (being Bragg angle) incident, wherein the non-diffracted light frequency is constant, and 1 grade of (or-1 grade) diffraction light frequency drifts about, the frequency shift amount ω of diffraction light
sEqual frequency of ultrasonic.
The present invention just is based on above-mentioned Bragg diffraction effect, and the two-frequency laser by two acousto-optic frequency shifter series connection is provided.Shown in Figure 2ly be two-frequency laser according to an embodiment of the invention, this laser comprises devices such as single frequency laser 1, optical fiber collimator 2, light-conductive optic fibre 3, optical fiber collimator 4, quarter-wave plate 5, wollaston prism 6, acousto-optical device 7, driver 8, acousto-optical device 9, driver 10, wollaston prism 11 and beam expanding lens 12.Wherein acousto-optical device 7 is formed a cover acousto-optic frequency shifter with driver 8, and acousto-optical device 9 is formed another set of acousto-optic frequency shifter with driver 10, two cover acousto-optic frequency shifter series connection.Said single frequency laser 1 is used to produce single-frequency laser, according to user demand, this single frequency laser can frequency stabilization also can not frequency stabilization.
As shown in Figure 2, the laser frequency that single frequency laser 1 sends is f0, gets into light-conductive optic fibre 3 through fiber coupler 2, and through optical fiber collimator 4 outputs.If what single frequency laser 1 sent is linearly polarized light, then make it become circularly polarized light through quarter-wave plate 5, if single frequency laser 1 sends is random polarization, then need not use quarter-wave plate 5.The laser of f0 gets into wollaston prism 6 through after the quarter-wave plate, is divided into two bundles that energy equates: P polarised light and the direction of vibration S polarised light vertical with paper that direction of vibration is parallel with paper.The P polarised light is incident to acousto-optical device 7 with Prague angle α, and the S polarised light is incident to acousto-optical device 7 with negative Prague angle-α.
It is signal to the acousto-optical device 7 of fs1 that driver 8 produces frequencies, and the transducer through acousto-optical device 7 produces frequency and is the ultrasonic wave of fs1 and passes acousto-optic crystal, forms Bragg grating.After the P polarised light process acousto-optical device 7 with the incident of α angle, its first-order diffraction light frequency becomes f0+fs1.Through after the acousto-optical device 7, its first-order diffraction light frequency becomes f0-fs1 with the S polarised light of-α angle incident.
After acousto-optical device 7 outgoing, frequency be the P polarised light of f0+fs1 with negative Bragg angle-α incident sound optical device 9, and frequency is that the S polarised light of f0-fs1 is with Bragg angle α incident sound optical device 9.It is signal to the acousto-optical device 9 of fs2 that driver 10 produces frequencies, and the transducer through acousto-optical device 9 produces frequency and is the ultrasonic wave of fs2 and passes acousto-optic crystal, forms Bragg grating.Through after the acousto-optical device 9, its first-order diffraction light frequency becomes f0+fs1-fs2 with the P polarised light of-α angle incident; After the S polarised light process acousto-optical device 9 with the incident of α angle, its first-order diffraction light frequency becomes f0-fs1+fs2.
Frequency is that the P polarised light of f0+fs1-fs2 and the angle of the S polarised light that frequency is f0-fs1+fs2 are 2 α, therefore can converge at wollaston prism 11 again, collimates through beam expanding lens 12 afterwards and expands bundle.The difference of the frequency of the laser beam of final output is:
Δf＝(f
0-f
s1+f
s2)-(f
0+f
s1-f
s2)＝2(f
s1-f
s2)
Through selecting two different driving frequencies, can obtain suitable output frequency difference 2 (f
S1-f
S2).Perhaps select adjustable driver for use, make the output frequency of one of them driver adjustable, thereby realize output frequency difference 2 (f
S1-f
S2) adjustable.
The concrete data of following substitution are carried out example.
Stabilizing He Ne laser 1 is sent the linearly polarized light that wavelength is 632.8nm, and its frequency is 4.74 * 10
8MHz gets into light-conductive optic fibre 3 through fiber coupler 2, and through optical fiber collimator 4 outputs, makes it become circularly polarized light through quarter-wave plate 5.Get into polarization splitting prism 6 then, be divided into two bundles that energy equates: the S polarised light that P polarised light that direction of vibration is parallel with paper and direction of vibration are vertical with light splitting surface.The P polarised light is incident to acousto-optical device 7 for 0.5 ° with Prague angle, and the S polarised light ° is incident to acousto-optical device 7 with negative Prague angle-0.5.
It is signal to the acousto-optical device 8 of 100MHz that driver 8 produces frequencies, and the transducer through acousto-optical device 8 produces frequency and is the ultrasonic wave of 100MHz and passes acousto-optic crystal, forms Bragg grating.After the P polarised light process acousto-optical device 7 with 0.5 ° of incident, its first-order diffraction light frequency becomes (4.74 * 10
8+ 100) MHz.After the S polarised light process acousto-optical device 7 with-0.5 ° of incident, its first-order diffraction light frequency becomes (4.74 * 10
8-100) MHz.
It is signal to the acousto-optical device 9 of 104MHz that driver 10 produces frequencies, and the transducer through acousto-optical device 9 produces frequency and is the ultrasonic wave of 104MHz and passes acousto-optic crystal, forms Bragg grating.After the S polarised light process acousto-optical device 9 with 0.5 ° of incident, its first-order diffraction light frequency becomes (4.74 * 10
8-100+104) MHz; After the P polarised light process acousto-optical device 9 with-0.5 ° of incident, its first-order diffraction light frequency becomes (4.74 * 10
8+ 100-104) MHz.
The S polarised light that comes out from acousto-optical device 9 and the angle of P polarised light are 2 α, therefore can converge at wollaston prism 11 again, collimate through beam expanding lens 12 afterwards and expand bundle.The difference of the frequency of the laser beam of final output is:
Δf＝(4.74×10
8-100+104)-(4.74×10
8+100-104)＝8MHz
Through selecting two different driving frequencies, can obtain suitable output frequency difference 2 (f
S1-f
S2).Perhaps select adjustable driver for use, make the output frequency of one of them driver adjustable, thereby realize output frequency difference 2 (f
S1-f
S2) adjustable.
Described in this specification is several kinds of preferred embodiment of the present invention, and above embodiment is only in order to explain technical scheme of the present invention but not limitation of the present invention.All those skilled in the art all should be within scope of the present invention under this invention's idea through the available technical scheme of logical analysis, reasoning, or a limited experiment.
Claims (5)
1. a two-frequency laser comprises single frequency laser, first wollaston prism, first driver, first acousto-optical device, second driver, rising tone optical device, second wollaston prism and beam expanding lens; Said first driver sends first drive signal that frequency is fs1 to said first acousto-optical device; Said second driver sends second drive signal that frequency is fs2 to said rising tone optical device, makes said first and second acousto-optical devices form a Bragg grating respectively; The frequency that said single frequency laser sends is that the laser of f0 is divided into orthogonal P polarised light of polarization state and S polarised light via said first wollaston prism; The P polarised light is incident to said first acousto-optical device with positive Bragg angle, and output frequency is the light of f0+fs1, and then is incident to said rising tone optical device with negative Bragg angle, and output frequency is the light of f0+fs1-fs2; The S polarised light is incident to said first acousto-optical device with negative Bragg angle, and output frequency is the light of f0-fs1, and then is incident to said rising tone optical device with positive Bragg angle, and output frequency is the light of f0-fs1+fs2; Two-beam closes Shu Houjing and is exported by said beam expanding lens in said second wollaston prism, the difference of output light frequency is 2 (f
S1-f
S2).
2. two-frequency laser according to claim 1 is characterized in that, the frequency adjustable of the drive signal of said first driver or the output of said second driver.
3. two-frequency laser according to claim 2 is characterized in that, when said single frequency laser polarization light output, puts a quarter-wave plate in said first wollaston prism the place ahead.
4. two-frequency laser according to claim 3 is characterized in that, said single frequency laser is a stabilized single-frequency laser.
5. according to any described two-frequency laser among the claim 1-4, it is characterized in that, at top speed the light beam that sends of single frequency laser transmit through light-conductive optic fibre.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010106192863A CN102570273A (en) | 2010-12-31 | 2010-12-31 | Double-frequency laser device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010106192863A CN102570273A (en) | 2010-12-31 | 2010-12-31 | Double-frequency laser device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102570273A true CN102570273A (en) | 2012-07-11 |
Family
ID=46415028
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010106192863A Pending CN102570273A (en) | 2010-12-31 | 2010-12-31 | Double-frequency laser device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102570273A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104283110A (en) * | 2014-10-17 | 2015-01-14 | 中国科学院武汉物理与数学研究所 | Multi-frequency laser time division multiplexing amplifier based on acoustic optical modulator |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62172777A (en) * | 1986-01-27 | 1987-07-29 | Yokogawa Electric Corp | Variable wavelength laser light source |
| US5485272A (en) * | 1993-12-17 | 1996-01-16 | U.S. Philips Corporation | Radiation-source unit for generating a beam having two directions of polarisation and two frequencies |
| CN1959471A (en) * | 2005-11-01 | 2007-05-09 | 安捷伦科技有限公司 | System and method for generating beams of light using an anisotropic acousto-optic modulator |
| CN101004346A (en) * | 2007-01-19 | 2007-07-25 | 清华大学 | Quasi-common path type feedback interferometer of laser in microchip |
-
2010
- 2010-12-31 CN CN2010106192863A patent/CN102570273A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62172777A (en) * | 1986-01-27 | 1987-07-29 | Yokogawa Electric Corp | Variable wavelength laser light source |
| US5485272A (en) * | 1993-12-17 | 1996-01-16 | U.S. Philips Corporation | Radiation-source unit for generating a beam having two directions of polarisation and two frequencies |
| CN1959471A (en) * | 2005-11-01 | 2007-05-09 | 安捷伦科技有限公司 | System and method for generating beams of light using an anisotropic acousto-optic modulator |
| CN101004346A (en) * | 2007-01-19 | 2007-07-25 | 清华大学 | Quasi-common path type feedback interferometer of laser in microchip |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104283110A (en) * | 2014-10-17 | 2015-01-14 | 中国科学院武汉物理与数学研究所 | Multi-frequency laser time division multiplexing amplifier based on acoustic optical modulator |
| CN104283110B (en) * | 2014-10-17 | 2017-06-23 | 中国科学院武汉物理与数学研究所 | Multifrequency LTS laser time sharing multiplexing amplifier based on acousto-optic modulator |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11243352B2 (en) | Polarization independent processing in integrated photonics | |
| US7375819B2 (en) | System and method for generating beams of light using an anisotropic acousto-optic modulator | |
| US7372576B2 (en) | System and method for generating beams of light using an anisotropic acousto-optic modulator | |
| US20100054753A1 (en) | Apparatus and method for stabilizing polarization state | |
| CN103245285B (en) | A kind of reflection type point diffraction carrier synchronization movable phase interfere pick-up unit and detection method | |
| CN102780153B (en) | Acousto-optic frequency sweeping laser based on acousto-optic deflection device | |
| CN102545015A (en) | Dual-frequency laser | |
| CN202853565U (en) | Acousto-optic heterodyne ineterferometer light path device | |
| JP2022526208A (en) | Orbital angular momentum generators and methods for polarization-modulated orbital angular momentum | |
| CN111130637B (en) | Measurement method and measurement system of photon spin-orbital angular momentum combined mode | |
| CN102147536A (en) | Dual-path controllable one-dimensional optic crystal lattice device | |
| CN102570273A (en) | Double-frequency laser device | |
| CN103744071A (en) | Linear scanning device for aplanatism wave surface transformation for orthophoria synthetic aperture laser imaging radar | |
| Niu et al. | Phase modulation characteristics analysis of liquid crystal spatial light modulator under oblique incidence | |
| RU2613943C1 (en) | Acousto-optic polarization transformer of laser radiation (versions) | |
| JP2013130807A (en) | Optical member and optical device | |
| US10094648B2 (en) | Homodyne optical sensor system incorporating a multi-phase beam combining system | |
| CN116222632B (en) | Fiber sweep frequency interference device based on birefringent crystal | |
| CN103424195A (en) | Phase-shifting shearing interferometer by rotating crystal plate | |
| Kotov | Broadband acousto-optic modulation of optical radiation | |
| CN211669852U (en) | Double-refraction interferometer and quantum optical experimental device based on double-refraction interferometer | |
| JP2014196912A (en) | Device and method for measuring optical frequency characteristic | |
| TWI483052B (en) | Wavelength modulation heterodyne light source | |
| Kotov et al. | Acoustooptic diffraction of three-color radiation on a single acoustic wave | |
| KR20100087791A (en) | Birefringence measuring method and apparatus using off-axis digital holography |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120711 |