CN108319092A - Utilize the method for being periodically totally reflected realization quasi-phase matched - Google Patents
Utilize the method for being periodically totally reflected realization quasi-phase matched Download PDFInfo
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- CN108319092A CN108319092A CN201810286480.0A CN201810286480A CN108319092A CN 108319092 A CN108319092 A CN 108319092A CN 201810286480 A CN201810286480 A CN 201810286480A CN 108319092 A CN108319092 A CN 108319092A
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/353—Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams
- G02F1/3544—Particular phase matching techniques
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/353—Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams
- G02F1/3544—Particular phase matching techniques
- G02F1/3548—Quasi phase matching [QPM], e.g. using a periodic domain inverted structure
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- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
A method of realizing quasi-phase matched using periodically total reflection, light wave is slanted through to the crystal of front/rear end beveling, so that after there is phase mismatch when collinearly being propagated with frequency doubled light in fundamental frequency light, light wave occurs to be totally reflected and generate in crystal and air surface can compensate for the phase shift difference of collinear phase mismatch, to realize the growth of quasi-phase matched and double frequency power.The present invention need not carry out complicated processing and high conversion efficiency to crystal.
Description
Technical field
It is specifically a kind of using in nonlinear crystal inner surface the present invention relates to a kind of technology in optical device field
The method that periodically quasi-phase matched is realized in total reflection
Background technology
It is carrying out realizing the main of phase matched when frequency conversion generates the laser of new wavelength using nonlinear material at present
Method has：Birefringence matching, modal phase matching and quasi-phase matching, but birefringence matching is by polarization and wave vector side
To limitation, for specific crystal, the corresponding phase matched angle of each incident wavelength is different from, so actually using
It is middle to be inconvenient to adjust；Modal phase matching is then difficult to realize frequency multiplication in the case where the overlapping area of each pattern is small；Quasi- phase
With then needing artificially to carry out periodic periodical poling to ferroelectric crystal, polarization cycle of high cost and certain is only used for
Specific wavelength.
Invention content
The present invention has for existing phase-matching technique to be not easy to adjust, of high cost, cannot meet different wave length simultaneously
The shortcomings of, it proposes a kind of method using periodically total reflection realization quasi-phase matched, light wave is entered from end face at a certain angle
It after being mapped to the crystal of front/rear end beveling, is totally reflected back and forth in crystal inner surface, fundamental frequency light is compensated using total reflection phase shift difference
With phase difference caused by frequency multiplication optical dispersion, phase matched is realized, while to double frequency power sustainable growth, in the phase of odd times
It is inverted in dry length, to make up the phase mismatch in frequency conversion, frequency conversion is made to increase always towards second harmonic
Strong direction carries out.The present invention need not carry out complicated processing and high conversion efficiency to crystal.
The present invention is achieved by the following technical solutions：
Light wave is slanted through the crystal of front/rear end beveling by the present invention so that is occurred when fundamental frequency light is collinearly propagated with frequency doubled light
After phase mismatch, light wave occurs to be totally reflected and generate in crystal and air surface can compensate for the phase shift difference of collinear phase mismatch,
To realize the growth for realizing quasi-phase matched and double frequency power.
The crystal is nonlinear crystal, it is preferred to use lithium columbate crystal.
The incidence end and exit end of the crystal cut with an oblique angle, which is preferably dimensioned to be：Thick 0.5mm, width
5mm, long 17mm.
To reduce scattering and improve the depth of parallelism, the surface of polishing is preferably the preferably polished processing in the surface of the crystal
Incident end face, provides the upper and lower surface that light wave is reflected in crystals at outgoing end face.
The oblique angle makes light wave by generating total reflection in crystal and air surface after incident end face incidence and will not
It is totally reflected in outgoing end face.
The incident end face and outgoing end face are preferably parallel.
The oblique fire, incidence angle are more than critical total internal.
The double frequency power and light wave are square directly proportional crystals order of reflection.
The light wave preferably through after lens or optical fiber collimator by surface feeding sputtering to crystals, due to internal anti-
Firing angle is more than the critical angle of total reflection, so fundamental frequency light and frequency doubled light are propagated in crystal with zigzag.The fundamental frequency light of interaction
When being propagated between former and later two pips with frequency doubled light, phase mismatch is will produce when collinearly propagating, utilizes fundamental frequency light and frequency multiplication
The phase shift difference caused by total reflection that light generates at crystal-Air Interface, phase mismatch when come to collinearly propagating are mended
It repays, so that fundamental frequency light meets conllinear quasi-phase matched condition with frequency doubled light in lithium niobate crystal body.It is produced during this
The walk-off effect of raw fundamental frequency light and frequency doubled light can be ignored, and so as to make fundamental frequency light multipass in nonlinear crystal, this will
Greatly prolong the equivalent length of frequency-doubling crystal.
Technique effect
Compared with prior art, the sustainable growth of frequency multiplication luminous power may be implemented in the present invention, do not need specific angle and
Polarization requires, and double frequency power and light wave are in the square directly proportional of crystals order of reflection.Since the present invention is in a monoblock
Quasi-phase matched is realized in crystal, without crystal is carried out slice stacking or is controlled using special growth or polarization process
To obtain specific period structure crystal.And the fundamental frequency light of different wave length of the present invention is likely to by changing crystal inner total reflection
Angle meets total reflection phase-matching condition.
Description of the drawings
Fig. 1 is crystal structure schematic diagram of the present invention；
Fig. 2 is crystal side view of the present invention；
Fig. 3 is crystal vertical view of the present invention；
Fig. 4 is the change schematic diagram of embodiment power；
In figure：The in planes of incidence, out exit facets, the upper surfaces a, the lower surfaces b.
Specific implementation mode
As shown in Figure 1, the present embodiment is by taking lithium columbate crystal as an example.Lithium niobate is uniaxial negative crystal, and there are two in crystal
The kind different light wave of refractive index.The refractive index of one of light wave, it is unrelated with wave vector direction, it is constant to be equal to no, referred to as ordinary
Light, abbreviation o light；The refractive index of another light wave, then change with the direction change of wave vector, is referred to as extraordinary ray, referred to as e
Light.Experiment lithium columbate crystal used is that z is tangentially cut, and when vertical light is in optical axis, o light and e are existed simultaneously in crystal
Light.O light and e optical indexs are related with wavelength, that is, meet Sellmeier equations.
Since crystal incidence end has the oblique angle of certain angle, fundamental frequency light to enter crystals by surface feeding sputtering, due to interior
Portion's angle of reflection is more than the critical angle of total reflection, so fundamental frequency light and frequency doubled light are propagated in crystal with zigzag：The base of interaction
It is conllinear to will produce phase mismatch when propagating when frequency light and frequency doubled light are propagated between former and later two pips, using fundamental frequency light with
The phase shift difference caused by total reflection that frequency doubled light generates at crystal-Air Interface, to be compensated to it, so that base
Frequency light meets phase-matching condition with frequency doubled light in lithium niobate crystal body.The major advantage of this technology is that it is in a monoblock
Quasi-phase matched is realized in crystal, without crystal is carried out slice stacking or is controlled using special growth or polarization process
To obtain specific period structure.Simultaneously because the condition of this phase matched is relatively easy to be met, the light of different wave length is all
Meet phase-matching condition possibly through crystal inner total reflection angle is changed.
The present embodiment detailed process is as follows：Light wave is exported from laser, utilizes lens or optical fiber collimator focussed collimated
Afterwards, with certain incident angles to crystal end-face, end face polishing treatment reduces the scattering of light.When the wavelength of fundamental frequency light is
When 1064nm, the refractive index of o lightFor 2.2291, e optical indexsIt is 2.1470；The wavelength of frequency doubled light is 532nm, e light folding
Penetrate rateIt is 2.2232.Crystal-cut angle is 40 °, and crystal is placed in air, air refraction n=1, wherein lithium niobate
The surface cirtical angle of total reflection with air is 27.8 °.If the angle of reflection in crystals is 33.3 °, according to geometrical relationship
And the law of refraction, the incidence angle of o light and e light is respectively 15 ° and 14.5 °.
The crystalline size is：Thick 0.5mm, long 17mm, width 5mm, when fundamental frequency light is collinearly propagated with frequency doubled light, with biography
The growth for broadcasting distance will appear collinear phase mismatch Δ kl=(2kω-k2ω) l, light paths of the l between front and back pip.But light wave
It is incident on after next surface, since reflection will appear reflection phase shift difference Φ=2 Φω-Φ2ω, wherein Φω,Φ2ωRespectively
The phase shift of fundamental frequency light and frequency doubled light.In order to ensure to realize the sustainable growth of second harmonic, the road of upper and lower surface in multiple reflections
Diameter distance needs to be coherence length (2m+1) times, that is, the condition met：Δ kl+ Φ=(2m+1) π.
Frequency doubled light exports after crystals sustainable growth from the rear end face of polishing treatment, and rear end face is also required to
The cutting of certain angle, it is therefore an objective to ensure that light wave will not be totally reflected in crystal exit end.
Since the polarization of light is different, conllinear wave vector and total reflection phase shift are all different：
A) for conllinear wave vector, k=2 π n/ λ, o light, e optical indexs correspond to n respectivelyo、ne。
B) for being totally reflected phase shift, o light corresponds to TE polarizations, phase shiftLight corresponds to TM
Polarization, phase shiftWherein n1,n2Respectively lithium columbate crystal under the polarization and wavelength
Refractive index, air refraction.
There are two types of types, respectively o+o → e and e+e → e for the lithium columbate crystal phase matched used in the present embodiment.Then
Specifically the condition of phase matched is respectivelyWith
Light wave, for 33.3 °, is 17mm by length with internal reflection angle, and thickness is the crystal of 0.5mm, then light wave is in crystal
Order of reflection be 51 times, i.e., frequency doubled light can continuous 51 growths, and double frequency power and order of reflection is square directly proportional.
For other wavelength, as long as this type-Ⅱphase matching equally may be implemented when meeting above-mentioned condition, specific only incident angle is not
With.
Above-mentioned specific implementation can by those skilled in the art under the premise of without departing substantially from the principle of the invention and objective with difference
Mode carry out local directed complete set to it, protection scope of the present invention is subject to claims and not by above-mentioned specific implementation institute
Limit, each implementation within its scope is by the constraint of the present invention.
Claims (10)
1. a kind of utilizing the method that periodically quasi-phase matched is realized in total reflection, which is characterized in that light wave is slanted through front and back end
The crystal of face beveling so that after fundamental frequency light phase mismatch occurs when collinearly being propagated with frequency doubled light, light wave is in crystal and air surface
Occur to be totally reflected and generate the phase shift difference that can compensate for collinear phase mismatch, quasi-phase matched and double frequency power are realized to realize
Growth.
2. according to the method described in claim 1, it is characterized in that, the crystal be nonlinear crystal.
3. method according to claim 1 or 2, characterized in that the crystal uses lithium columbate crystal.
4. according to the method described in claim 1, it is characterized in that, the incidence end and exit end of the crystal cut with an oblique angle.
5. method according to claim 1 or 2 or 4, characterized in that the size of the crystal is：Thick 0.5mm, width
5mm, long 17mm.
6. according to the method described in claim 1, it is characterized in that, the polished processing in the surface of the crystal is to reduce scattering simultaneously
Improve the depth of parallelism.
7. according to the method described in claim 4, it is characterized in that, the oblique angle make light wave by after incident end face incidence
Crystal generates total reflection with air surface and will not be totally reflected in outgoing end face.
8. method according to claim 1 or claim 7, characterized in that the incident end face is parallel with outgoing end face.
9. according to the method described in claim 1, it is characterized in that, the oblique fire, incidence angle be more than critical total internal.
10. according to the method described in claim 1, it is characterized in that, the double frequency power and light wave are in crystals reflection time
Several squares directly proportional.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05289137A (en) * | 1992-04-10 | 1993-11-05 | Sony Corp | Wavelength converter and manufacture thereof |
| CN1448758A (en) * | 2002-03-29 | 2003-10-15 | 中国科学院物理研究所 | Non-linear optic crystal laser variable frequency phase adapter |
| CN1547296A (en) * | 2003-12-04 | 2004-11-17 | 山东大学 | A bismuth borate noncollinear double frequency crystal device |
| JP2005106954A (en) * | 2003-09-29 | 2005-04-21 | Japan Steel Works Ltd:The | Laser wavelength converting element |
| CN104104005A (en) * | 2014-06-06 | 2014-10-15 | 中国科学院理化技术研究所 | Walk-off compensation device of double-lath structure |
-
2018
- 2018-03-30 CN CN201810286480.0A patent/CN108319092A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05289137A (en) * | 1992-04-10 | 1993-11-05 | Sony Corp | Wavelength converter and manufacture thereof |
| CN1448758A (en) * | 2002-03-29 | 2003-10-15 | 中国科学院物理研究所 | Non-linear optic crystal laser variable frequency phase adapter |
| JP2005106954A (en) * | 2003-09-29 | 2005-04-21 | Japan Steel Works Ltd:The | Laser wavelength converting element |
| CN1547296A (en) * | 2003-12-04 | 2004-11-17 | 山东大学 | A bismuth borate noncollinear double frequency crystal device |
| CN104104005A (en) * | 2014-06-06 | 2014-10-15 | 中国科学院理化技术研究所 | Walk-off compensation device of double-lath structure |
Non-Patent Citations (2)
| Title |
|---|
| BHASWATI MEDHI ET AL: "Analytical study of broadband second harmonic generation by total internal reflection-quasi phase matching using the concept of highly multimodal nonlinear guided wave approach in a tapered isotropic slab of zinc telluride crystal", 《OPTIK》 * |
| MINAKSHI DEB BARMA ET AL: "Total internal reflection quasiphase matching-based broadband second harmonic generation in a plane-parallel uniaxial crystal of lithium niobate", 《OPTICAL ENGINEERING》 * |
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Application publication date: 20180724 |