CN112271545B - Composite optical parametric oscillator based on single nonlinear crystal - Google Patents
Composite optical parametric oscillator based on single nonlinear crystal Download PDFInfo
- Publication number
- CN112271545B CN112271545B CN202010951231.6A CN202010951231A CN112271545B CN 112271545 B CN112271545 B CN 112271545B CN 202010951231 A CN202010951231 A CN 202010951231A CN 112271545 B CN112271545 B CN 112271545B
- Authority
- CN
- China
- Prior art keywords
- light
- crystal
- optical parametric
- parametric oscillator
- pump
- 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.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/106—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity
- H01S3/108—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
- H01S3/0602—Crystal lasers or glass lasers
- H01S3/0606—Crystal lasers or glass lasers with polygonal cross-section, e.g. slab, prism
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/08—Construction or shape of optical resonators or components thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/08—Construction or shape of optical resonators or components thereof
- H01S3/08086—Multiple-wavelength emission
- H01S3/0809—Two-wavelenghth emission
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/106—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity
- H01S3/108—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering
- H01S3/1083—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering using parametric generation
Abstract
The invention relates to a composite optical parametric oscillator based on a monolithic nonlinear crystal, which comprises: the device comprises a pump laser, a coupling input mirror, a nonlinear crystal and a coupling output mirror; the composite optical parametric oscillator includes a first optical parametric oscillator and a second optical parametric oscillator; the coupling input mirror, the area between the first light-passing surface and the bottom surface of the nonlinear crystal and the coupling output mirror form a first optical parametric oscillator; the coupling input mirror, the area between the second light-passing surface and the bottom surface of the nonlinear crystal and the coupling output mirror form a second optical parametric oscillator. The two optical parametric oscillators are integrated in the resonant cavity based on the single crystal, so that the output of medium-wave and long-wave infrared lasers can be realized simultaneously, the optical path structure of the traditional cascade optical parametric oscillator is greatly simplified, the use of optical elements is effectively reduced, and the stability, reliability and compactness of the whole device are improved while the cost is reduced.
Description
Technical Field
The invention relates to the technical field of laser, in particular to a composite optical parametric oscillator based on a single nonlinear crystal.
Background
The medium-long wave infrared bands 3-5 μm and 8-12 μm are two extremely important atmospheric windows, the atmospheric absorption and scattering loss of the infrared radiation of the bands is extremely small, the infrared radiation can be effectively transmitted in various severe atmospheric environments such as turbid air, smoke, fog, haze, rain, snow and the like, the two bands cover absorption peaks of a plurality of molecular gases, toxic reagents, air, water and soil pollutants, human respiratory components and various explosive reagents, and meanwhile, the wavelength range is also the wavelength response range of the medium-long wave infrared focal plane detector, so that the medium-long wave infrared coherent radiation light sources of the two bands have great application values and prospects in the fields of atmospheric monitoring, optical remote sensing, spectral analysis, space optical communication, environmental protection, medical treatment, photoelectric countermeasure and the like.
In the current technical schemes for generating the medium-and-long-wave infrared band light sources, the solid laser-based nonlinear frequency conversion technology has the outstanding advantages of wide-band continuous tunable property, multiple mechanisms (repetition frequency of 1Hz-GHz and pulse width CW-fs), full solidification, compact structure, practicability, precision and the like, so that the solid laser-based nonlinear frequency conversion technology becomes the medium-and-long-wave infrared laser technology which is most researched and widely applied at home and abroad at present, and the technical approaches comprise Difference Frequency (DF), Optical Parameter Generation (OPG), Optical Parameter Oscillation (OPO), Optical Parameter Amplifier (OPA) and the like. However, the output wavelength of the fundamental frequency pump source used in the nonlinear frequency conversion technology is usually about 1 μm or 2 μm, and in order to convert the wavelength into the mid-long wave infrared band, more than two stages of frequency conversion devices are often needed to implement the wavelength conversion, which inevitably makes the structure of the laser system more complicated and more costly, and further reduces the reliability and stability of the laser due to the increase of the number of optical devices. In many application occasions, especially in the field of national defense, the light weight and the reliability of the medium-wavelength and long-wavelength infrared laser usually have very strict requirements, so that a high-reliability compact medium-wavelength and long-wavelength infrared laser technical scheme needs to be broken through urgently.
Disclosure of Invention
Aiming at the defects in the prior art, the invention realizes the operation of two optical parametric oscillators in a monolithic crystal and a single resonant cavity by carrying out specific cutting on the monolithic nonlinear optical crystal, and provides an all-solid-state medium-long wave infrared laser source with compact structure and high reliability. The invention relates to a composite optical parametric oscillator based on a monolithic nonlinear crystal, which comprises:
the device comprises a pump laser, a coupling input mirror, a nonlinear crystal and a coupling output mirror;
the composite optical parametric oscillator includes a first optical parametric oscillator and a second optical parametric oscillator; the coupling input mirror, the area through which light passes between the first light-passing surface and the bottom surface of the nonlinear crystal (specifically, the area through which light passes between the first light-passing surface and the bottom surface light reflection point M) and the coupling output mirror form a first optical parametric oscillator; the coupling input mirror, the area through which light passes between the second light-passing surface and the bottom surface of the nonlinear crystal (specifically, the area through which light passes between the second light-passing surface and the bottom surface light reflection point M) and the coupling output mirror form a second optical parametric oscillator;
the pump laser is used for outputting first pump laser, and the first pump laser enters the first optical parametric oscillator;
the coupling input mirror is used for coupling and injecting the first pumping laser into the composite optical parametric oscillator, and serves as a face mirror of the composite optical parametric oscillator after a specific film layer is plated (the face mirror is highly transparent to the pumping light, and other parametric light is highly reflective);
the nonlinear crystal is cut according to a specific mode to meet phase matching conditions of a first optical parametric oscillator and a second optical parametric oscillator, and finally target laser output is generated; the coupling output mirror belongs to a cavity mirror on the other side of the composite optical parametric oscillator, and realizes the operation of the composite optical parametric oscillator and the target laser output by plating a specific film layer;
the first pump light output from the pump laser is injected into the composite optical parametric oscillator through the coupling input mirror, the first pump light is normally incident on a first light passing surface of the nonlinear crystal at 0 degree, the propagation direction of the light beam in the crystal meets the phase matching condition of the first optical parametric oscillator to generate first signal light and first idler light, after all parametric lights are totally reflected on the bottom surface of the crystal, the first idler light is transmitted and output through the coupling output mirror, the remaining first pump light is transmitted and filtered by the coupling input mirror, the first signal light continuously oscillates in the cavity, and after the first idler light is totally reflected on the bottom surface of the crystal, the propagation direction meets the phase matching condition of the second optical parametric oscillator, so that the first signal light serves as second pump light at the moment, second signal light and second idler light are generated, and output of target laser is finally achieved.
Further, the nonlinear crystal is a birefringent phase-matched nonlinear optical crystal, which has a high transmittance for all parametric light of the first optical parametric oscillator and the second optical parametric oscillator, and is one of a KTP crystal, a KTA crystal, a BaGa4Se7 crystal, an AgGaS/Se2 crystal, a ZnGeP2 crystal, a CdSe crystal or a GaSe crystal, and the method for cutting in a specific manner comprises the following steps:
s1, selecting a certain principal plane (paper plane in fig. 2) of the crystal, and determining phase matching angles of the first optical parametric oscillator and the second optical parametric oscillator in the principal plane, where the specific determination method is to calculate by using a formula or to obtain them quickly by using SNLO software, and they are respectively denoted as θ 1 and θ 2, where θ 1 and θ 2 are angles in which an optical axis of the crystal in the certain principal plane (paper plane) of the selected nonlinear optical crystal is an edge, one edge of the θ 1 angle is an optical axis, and one edge of the θ 2 angle is also an optical axis, as shown in fig. 2;
s2, determining an angular bisector of an included angle between two direction lines (the other side of the angle theta 1 and the other side of the angle theta 2) determined by the angle theta 1 and the angle theta 2 in the main plane, and cutting the crystal perpendicular to the main plane along the angular bisector to be used as a bottom surface of the crystal;
s3, rotating a straight line intersecting a bottom surface of the crystal and the main plane (paper plane) clockwise along the main plane | theta 1-theta 2 | 2 to obtain a phase matching angle direction (line) of the first optical parametric oscillator, and cutting the plane along the direction to obtain a first light passing surface of the crystal;
s4, rotating a line intersecting a bottom surface of the crystal and the principal plane (paper plane) in the principal plane in the counterclockwise direction |. θ 1- θ 2 |/2 to obtain a phase matching angular direction (line) of the second optical parametric oscillator, and slicing the plane along the direction to obtain a second light-passing surface of the crystal.
Specifically, the nonlinear crystal is a birefringent phase-matched nonlinear optical crystal cut according to a specific method, and the crystal meets the following conditions: when the first pump light is normally incident from the first light-passing surface of the crystal, the phase matching condition of the first optical parametric oscillator is met; the first pump light, the first signal light and the first idler frequency light are all totally reflected at the bottom of the nonlinear crystal; the propagation direction of the first signal light after total reflection, namely the second pump light, meets the phase matching requirement of the second optical parametric oscillator; the first pump light and the parametric light of the second optical parametric oscillator are both vertical to the second light-passing surface of the crystal and are emitted out of the crystal; a first light passing surface of the crystal is plated with a dielectric film which is highly transparent to the first pump light, the first signal light and the second signal light, and a second light passing surface of the crystal is plated with a dielectric film which is highly transparent to the first pump light, the second signal light and the second idler frequency light.
Specifically, the coupling input mirror is plated with a specific film layer: the left side surface is plated with a dielectric film which is highly transparent to the first pump light, and the right side surface is plated with a dielectric film which is highly transparent to the first pump light and highly reflective to the first signal light and the second signal light; the coupling output mirror is plated with a specific film layer: the left side surface is plated with a dielectric film which is highly reflective to the first pump light and the second pump light, partially transmissive to the second signal light and highly transmissive to the second idler frequency light, and the right side surface is plated with a dielectric film which is highly transmissive to the second signal light and the second idler frequency light.
Specifically, when the polarization states of the second pump light and the second signal light are the same, the optical parametric oscillator further includes a second half-wave plate, where the second half-wave plate is a λ/2 wave plate of the second pump laser and is used to adjust the polarization state of the second pump light to the polarization direction required by the second optical parametric oscillator.
Preferably, the optical parametric oscillator further comprises a first half wave plate, wherein the first half wave plate is a λ/2 wave plate of the first pump laser and is used for adjusting the polarization state of the first pump light to the polarization direction required by the first optical parametric oscillator.
Specifically, the pump laser is a laser oscillator or a laser amplifier of any linear polarization system, and is configured to output a first pump laser, and the operation mode of the pump laser is continuous, quasi-continuous, or pulsed.
Compared with the prior art, the composite optical parametric oscillator based on the single nonlinear crystal has the beneficial effects that:
on one hand, the two optical parametric oscillators are integrated in the resonant cavity based on the single crystal, so that the output of medium-wave and long-wave infrared laser can be realized simultaneously, the optical path structure of the traditional cascade optical parametric oscillator is greatly simplified, the use of optical elements is effectively reduced, the cost is reduced, and the stability, reliability and compactness of the whole device are improved;
on the other hand, because the two optical parametric oscillators share one resonant cavity, the pumping light and the seed light of the second optical parametric oscillator have consistent spatial distribution characteristics and better mode matching, and the conversion efficiency of the second optical parametric oscillator is favorably improved.
Drawings
FIG. 1 is a schematic structural diagram of an on-line monitoring device suitable for laser cleaning quality;
fig. 2 is a schematic diagram of the method steps of cutting the nonlinear crystal in a specific manner.
The optical fiber laser comprises a 1-pump laser, a 2-first half wave plate, a 3-coupling input mirror, a 4-nonlinear crystal (41-a first light passing surface (an incident plane), a 42-a second light passing surface (an emergent plane), a 43-bottom surface, a 431-bottom surface light reflection point M, a 5-coupling output mirror, a 6-second half wave plate, a 7-main plane of the crystal (namely a plane of the paper), an optical axis of the crystal 71, the other side of an angle 711-theta 1, the other side of an angle 712-theta 2, a bisector of an included angle between two direction lines (the other side of the angle theta 1 and the other side of the angle theta 2) determined by 72-theta 1 and theta 2 in the main plane, and 8-rays.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
Example 1
The invention relates to a composite optical parametric oscillator based on a monolithic nonlinear crystal, which comprises:
the device comprises a pump laser, a coupling input mirror, a nonlinear crystal and a coupling output mirror;
the composite optical parametric oscillator includes a first optical parametric oscillator and a second optical parametric oscillator; the coupling input mirror, the area through which light passes between the first light-passing surface and the bottom surface of the nonlinear crystal (specifically, the area through which light passes between the first light-passing surface and the bottom surface light reflection point M) and the coupling output mirror form a first optical parametric oscillator; the coupling input mirror, the area through which light passes between the second light-passing surface and the bottom surface of the nonlinear crystal (specifically, the area through which light passes between the second light-passing surface and the bottom surface light reflection point M) and the coupling output mirror form a second optical parametric oscillator;
the pump laser is used for outputting first pump laser entering the first optical parametric oscillator;
the coupling input mirror is used for coupling and injecting the first pump laser into the composite optical parametric oscillator, and simultaneously serves as a surface mirror of the composite optical parametric oscillator after a specific film layer is plated (the surface mirror is highly transparent to the pump light, and other parametric light is highly reflective);
the nonlinear crystal is cut according to a specific mode to meet phase matching conditions of a first optical parametric oscillator and a second optical parametric oscillator, and finally target laser output is generated; the coupling output mirror belongs to a cavity mirror on the other side of the composite optical parametric oscillator, and realizes the operation of the composite optical parametric oscillator and the target laser output by plating a specific film layer;
the first pump light output from the pump laser is injected into the composite optical parametric oscillator through the coupling input mirror, the first pump light is normally incident on a first light passing surface of the nonlinear crystal at 0 degree, the propagation direction of the light beam in the crystal meets the phase matching condition of the first optical parametric oscillator to generate first signal light and first idler light, after all the parametric light is totally reflected on the bottom surface of the crystal, the first idler light is transmitted and output through the coupling output mirror, the remaining first pump light is transmitted and filtered by the coupling input mirror, the first signal light continuously oscillates in the cavity, and after the first idler light is totally reflected on the bottom surface of the crystal, the propagation direction meets the phase matching condition of the second optical parametric oscillator, so that the first signal light serves as second pump light at the moment, second signal light and second idler light are generated, and output of target laser is finally achieved.
The nonlinear crystal is a birefringent phase-matched nonlinear optical crystal, has high transmittance for all parametric light of the first optical parametric oscillator and the second optical parametric oscillator, is one of a KTP crystal, a KTA crystal, a BaGa4Se7 crystal, an AgGaS/Se2 crystal, a ZnGeP2 crystal, a CdSe crystal or a GaSe crystal, and is cut according to a specific mode:
s1, selecting a certain principal plane of the crystal, and determining phase matching angles of the first optical parametric oscillator and the second optical parametric oscillator in the principal plane, where the specific determination method is to calculate by using a formula or to obtain quickly by using SNLO software, and the angles are respectively denoted as θ 1 and θ 2, where θ 1 and θ 2 are angles in which an optical axis of the crystal in the certain principal plane (the paper plane) of the selected nonlinear optical crystal is an edge, one edge of the θ 1 angle is an optical axis, and one edge of the θ 2 angle is also an optical axis, as shown in fig. 2;
the phase matching types of the first optical parametric oscillator and the second optical parametric oscillator are the same, and are specifically divided into two types, i-type phase matching and ii-type phase matching, and taking a positive uniaxial crystal as an example, the calculation formula for calculating the phase matching angles theta 1 and theta 2 of the first optical parametric oscillator and the second optical parametric oscillator by using the formula is as follows:
the calculation formula of the phase matching angles theta 1 and theta 2 in the class I phase matching is as follows
The calculation formula of the phase matching angles theta 1 and theta 2 in the class II phase matching is as follows
Wherein the content of the first and second substances,
for the phase matching angle in class I phase matching,
for the phase matching angle in the class II phase matching,
refractive indexes of signal light o light, pump light o light and idler frequency light e light in the crystal are respectively;
s2, determining an angular bisector of an included angle between two direction lines (the other side of the angle theta 1 and the other side of the angle theta 2) determined by the angle theta 1 and the angle theta 2 in the main plane, and cutting the crystal perpendicular to the main plane along the angular bisector to be used as a bottom surface of the crystal;
s3, rotating a straight line intersecting a bottom surface of the crystal and the main plane (paper plane) clockwise along the main plane | theta 1-theta 2 | 2 to obtain a phase matching angle direction (line) of the first optical parametric oscillator, and cutting the plane along the direction to obtain a first light passing surface of the crystal;
s4, rotating a line intersecting a bottom surface of the crystal and the principal plane (paper plane) in the principal plane in the counterclockwise direction |. θ 1- θ 2 |/2 to obtain a phase matching angular direction (line) of the second optical parametric oscillator, and slicing the plane along the direction to obtain a second light-passing surface of the crystal.
The nonlinear crystal is a birefringent phase-matched nonlinear optical crystal cut according to a specific method, and the crystal meets the following conditions: when the first pump light is normally incident from the first light-passing surface of the crystal, the phase matching condition of the first optical parametric oscillator is met; the first pump light, the first signal light and the first idler frequency light are all totally reflected at the bottom of the nonlinear crystal; the propagation direction of the first signal light after total reflection, namely the second pump light, meets the phase matching requirement of the second optical parametric oscillator; the first pump light and the parametric light of the second optical parametric oscillator are both vertical to the second light-passing surface of the crystal and are emitted out of the crystal; the first light-passing surface of the crystal is plated with a dielectric film which is highly transparent to the first pump light, the first signal light and the second signal light, and the second light-passing surface is plated with a dielectric film which is highly transparent to the first pump light, the second signal light and the second idler frequency light.
The coupling input mirror is plated with a specific film layer: the left side surface is plated with a dielectric film which is highly transparent to the first pump light, and the right side surface is plated with a dielectric film which is highly transparent to the first pump light and highly reflective to the first signal light and the second signal light; the coupling output mirror is plated with a specific film layer: the left side surface is plated with a dielectric film which is highly reflective to the first pump light and the second pump light, partially transmissive to the second signal light and highly transmissive to the second idler frequency light, and the right side surface is plated with a dielectric film which is highly transmissive to the second signal light and the second idler frequency light.
When the polarization states of the second pump light and the second signal light are consistent, the optical parametric oscillator further comprises a second half-wave plate, wherein the second half-wave plate is a lambda/2 wave plate of the second pump laser and is used for adjusting the polarization state of the second pump light to be the polarization direction required by the second optical parametric oscillator. The second half-wave plate may not be needed if the second pump light is orthogonal to the polarization state of the second signal light.
The optical parametric oscillator further comprises a first half wave plate, wherein the first half wave plate is a lambda/2 wave plate of the first pump laser and is used for adjusting the polarization state of the first pump light to be the polarization direction required by the first optical parametric oscillator.
The pump laser is a laser oscillator or a laser amplifier of any linear polarization system, is used for outputting first pump laser, and has a continuous, quasi-continuous or pulse operation mode
Specifically describing the present embodiment with reference to fig. 1, the composite optical parametric oscillator based on monolithic nonlinear crystal in the present embodiment includes a pump laser, a first half-wave plate, a second half-wave plate, and a composite optical parametric oscillator composed of a coupling input mirror, a nonlinear crystal, and a coupling output mirror;
the linearly polarized 2.09 μm laser output from the pump laser is injected into the composite optical parametric oscillator through the coupling input mirror after the polarization direction is adjusted by the first half-wave plate. The 2.09 μm laser is incident on the first light-passing surface of the nonlinear crystal at 0 ° normal incidence as the first pump light, and the propagation direction and polarization state of the light beam in the crystal meet the phase matching condition of the first optical parametric oscillator, first signal light with the wavelength of 2.8 μm and first idler frequency light with the wavelength of 8.0 μm are generated, after all the parametric light is totally reflected at the bottom of the crystal, the first idler frequency light is transmitted and output by the coupling-out mirror, the rest first pump light is transmitted and filtered by the coupling-in mirror, the rest 2.8 μm first signal light continuously oscillates in the cavity, when it is totally reflected at the bottom of the crystal, the propagation direction meets the phase matching condition of the second optical parametric oscillator, therefore, the 2.8 μm first signal light acts as the second pump light at this time, and generates the second signal light with the wavelength of 4.3 μm and the second idler light with the wavelength of 8.0 μm, and finally, the output of the 4.3 μm mid-infrared laser and the 8.0 μm long-wavelength infrared laser through the coupling-out mirror is realized simultaneously.
Example 2
This embodiment further illustrates example 1, in which the left side surface of the input coupling mirror is coated with 2.09 μm antireflection film, the right side surface thereof is coated with 2.09 μm antireflection film, and 2.8 μm and 4.3 μm high-reflection films. The transmittance of the antireflection film is more than 99 percent, and the reflectivity of the high-reflection film is more than 99 percent. The rest is the same as in example 1.
Example 3
In this embodiment, example 2 is described further, in the nonlinear crystal ZnGeP2 crystal according to this embodiment, since the first light-passing surface and the second light-passing surface are each coated with an antireflection film having a wavelength band of 2.09 μm, 2.8 μm, 4.3 μm, and 8 μm, the cut angle of the first light-passing surface is 51.3 ° and the cut angle of the second light-passing surface is 46.7 ° respectively, the first and second optical parametric oscillators are both type i phase-matched, i.e., o → e + e. The rest is the same as example 2.
Example 4
In this embodiment, example 3 is further described, in which the coupling-out mirror is made of CaF2, the left side is coated with a 2.09 μm and 2.8 μm high-reflective film, a 4.3 μm partially reflective film and a 8.0 μm high-transparent dielectric film, and the right side is coated with a 4.3 μm and 8.0 μm high-transparent dielectric film. The rest is the same as in example 3.
Example 5
To further explain embodiment 4, the second half-wave plate in this embodiment is a 2.8 μm half-wave plate, and is used to rotate the polarization state of the 2.8 μm first signal light generated by the first optical parametric oscillator by 90 ° so that the polarization state meets the requirement of the second optical parametric oscillator on the polarization state of the second pump light, specifically, the second optical parametric oscillator requires the 2.8 μm light to be o light, and the 2.8 μm light generated by the first optical parametric oscillator is e light. The rest is the same as example 4.
Example 6
In this embodiment, example 1 is described further, the nonlinear crystal according to this embodiment may be replaced with a BaGaS7 crystal, and accordingly, each of the first light-passing surface and the second light-passing surface is coated with an antireflection film having a wavelength band of 2.09 μm, 2.8 μm, 4.3 μm, and 8 μm, and the first light-passing surface has a cutting angle θ 1 of 4.9 ° and the second light-passing surface has a cutting angle θ 2 of 30.6 °, so that the first optical parametric oscillator and the second optical parametric oscillator are both in type i phase matching of o → e + e. The rest is the same as in example 1.
Example 7
In this embodiment, example 1 is described further, the nonlinear crystal according to this embodiment may be replaced with a KTiOAsO4 crystal, and accordingly, the first light-passing surface and the second light-passing surface are each coated with an antireflection film in a wavelength band of 1.06 μm, 1.5 μm, 2.7 μm, and 3.5 μm, and the first light-passing surface has a cutting angle θ 1 of 41.4 ° and the second light-passing surface has a cutting angle θ 2 of 55.6 °, so that the first and second optical parametric oscillators are both phase-matched in class ii of o → e + o. The rest is the same as in example 1.
Example 8
In this embodiment, example 1 is described further, the nonlinear crystal according to this embodiment may be replaced with an AgGaS2 crystal, and accordingly, each of the first light-passing surface and the second light-passing surface is coated with an antireflection film having a wavelength band of 2.09 μm, 2.8 μm, 4.3 μm, and 8 μm, and the first light-passing surface has a cutting angle θ 1 of 39.7 ° and the second light-passing surface has a cutting angle θ 2 of 47.2 °, so that the first optical parametric oscillator and the second optical parametric oscillator are both class ii phase-matched e → o + e. The rest is the same as in example 1.
Example 9
In this embodiment, example 1 is described further, the nonlinear crystal according to this embodiment may be replaced with a GaSe crystal, and accordingly, the first light-passing surface and the second light-passing surface are each coated with an antireflection film in a wavelength band of 2.09 μm, 2.8 μm, 4.3 μm, and 8 μm, and the first light-passing surface has a cutting angle θ 1 of 22.2 ° and the second light-passing surface has a cutting angle θ 2 of 18.2 °, so that the first optical parametric oscillator and the second optical parametric oscillator are both phase-matched in class ii of e → e + o. The rest is the same as in example 1.
Claims (4)
1. A monolithic nonlinear crystal-based composite optical parametric oscillator comprising:
the device comprises a pump laser, a coupling input mirror, a nonlinear crystal and a coupling output mirror;
the composite optical parametric oscillator includes a first optical parametric oscillator and a second optical parametric oscillator; the coupling input mirror, the area between the first light-passing surface and the bottom surface of the nonlinear crystal and the coupling output mirror form a first optical parametric oscillator; the coupling input mirror, the area between the second light-passing surface and the bottom surface of the nonlinear crystal and the coupling output mirror form a second optical parametric oscillator;
the pump laser is used for outputting first pump laser, and the first pump laser enters the first optical parametric oscillator;
the coupling input mirror is used for coupling and injecting the first pumping laser into the composite optical parametric oscillator, and serves as a surface mirror of the composite optical parametric oscillator after a specific film layer is plated;
the nonlinear crystal is cut according to a specific mode to meet phase matching conditions of a first optical parametric oscillator and a second optical parametric oscillator, and finally target laser output is generated; the coupling output mirror belongs to a cavity mirror on the other side of the composite optical parametric oscillator, and realizes the operation of the composite optical parametric oscillator and the target laser output by plating a specific film layer;
injecting first pump light output from a pump laser into the composite optical parametric oscillator through the coupling input mirror, wherein the first pump light is normally incident on a first light passing surface of the nonlinear crystal at 0 degrees, the propagation direction of the light beam in the crystal meets the phase matching condition of the first optical parametric oscillator to generate first signal light and first idler light, after all the parametric light is totally reflected on the bottom surface of the crystal, the first idler light is transmitted and output through the coupling output mirror, the remaining first pump light is transmitted and filtered by the coupling input mirror, the first signal light continuously oscillates in a cavity, and after the first pump light is totally reflected on the bottom surface of the crystal, the propagation direction meets the phase matching condition of the second optical parametric oscillator, so that the first signal light serves as second pump light at the moment, second signal light and second idler light are generated, and target laser output is finally achieved;
the nonlinear crystal is a birefringent phase-matched nonlinear optical crystal, has high transmittance for all parametric light of the first optical parametric oscillator and the second optical parametric oscillator, is one of a KTP crystal, a KTA crystal, a BaGa4Se7 crystal, an AgGaS/Se2 crystal, a ZnGeP2 crystal, a CdSe crystal or a GaSe crystal, and is cut according to a specific mode:
s1, selecting a certain main plane of the crystal, and determining phase matching angles of the first optical parametric oscillator and the second optical parametric oscillator in the main plane, which are respectively marked as theta 1 and theta 2, wherein the theta 1 and the theta 2 are angles taking the optical axis of the crystal in the certain main plane of the selected nonlinear optical crystal as one side, one side of the theta 1 angle is the optical axis, and one side of the theta 2 angle is the optical axis;
s2, determining an angular bisector of an included angle between two direction lines determined by theta 1 and theta 2 in the main plane, and cutting the crystal along the angular bisector and perpendicular to the main plane to be used as a bottom surface of the crystal;
s3, rotating a straight line intersecting a bottom surface of the crystal and the main plane clockwise | theta 1-theta 2 | or 2 in the main plane to obtain a phase matching angle direction of the first optical parametric oscillator, and cutting the plane along the direction to obtain a first light-passing surface of the crystal;
s4, rotating a straight line intersecting a bottom surface of the crystal and the main plane along the counterclockwise direction | theta 1-theta 2 | or 2 in the main plane to obtain a phase matching angle direction of the second optical parametric oscillator, and performing plane cutting along the direction to obtain a second light-passing surface of the crystal;
the nonlinear crystal is a birefringent phase-matched nonlinear optical crystal cut according to a specific method, and the crystal meets the following conditions: when the first pump light is normally incident from the first light-passing surface of the crystal, the phase matching condition of the first optical parametric oscillator is met; the first pump light, the first signal light and the first idler frequency light are all totally reflected at the bottom of the nonlinear crystal; the propagation direction of the first signal light after total reflection, namely the second pump light, meets the phase matching requirement of the second optical parametric oscillator; the first pump light and the parametric light of the second optical parametric oscillator are both vertical to the second light-passing surface of the crystal and are emitted out of the crystal; a first light-passing surface of the crystal is plated with a dielectric film which is highly transparent to first pump light, first signal light and second signal light, and a second light-passing surface of the crystal is plated with a dielectric film which is highly transparent to the first pump light, the second signal light and the second idler frequency light;
the coupling input mirror is plated with a specific film layer: the left side surface is plated with a dielectric film which is highly transparent to the first pump light, and the right side surface is plated with a dielectric film which is highly transparent to the first pump light and highly reflective to the first signal light and the second signal light; the coupling output mirror is plated with a specific film layer: the left side surface is plated with a dielectric film which is highly reflective to the first pump light and the second pump light, partially transmissive to the second signal light and highly transmissive to the second idler frequency light, and the right side surface is plated with a dielectric film which is highly transmissive to the second signal light and the second idler frequency light.
2. The monolithic nonlinear crystal-based composite optical parametric oscillator of claim 1, further comprising a second half-wave plate when the polarization states of the second pump light and the second signal light are the same, the second half-wave plate being a λ/2 wave plate of the second pump laser for adjusting the polarization state of the second pump light to the polarization direction required by the second optical parametric oscillator.
3. The monolithic nonlinear crystal based composite optical parametric oscillator of claim 1, further comprising a first half wave plate, wherein the first half wave plate is a λ/2 wave plate of the first pump laser for adjusting the polarization state of the first pump light to the polarization direction required by the first optical parametric oscillator.
4. The monolithic nonlinear crystal based composite optical parametric oscillator according to claim 2 or 3, wherein the pump laser is a linearly polarized laser oscillator or a laser amplifier of any system, and is operated continuously, quasi-continuously or in pulses to output the first pump laser.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010951231.6A CN112271545B (en) | 2020-09-11 | 2020-09-11 | Composite optical parametric oscillator based on single nonlinear crystal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010951231.6A CN112271545B (en) | 2020-09-11 | 2020-09-11 | Composite optical parametric oscillator based on single nonlinear crystal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112271545A CN112271545A (en) | 2021-01-26 |
| CN112271545B true CN112271545B (en) | 2022-06-07 |
Family
ID=74349557
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010951231.6A Active CN112271545B (en) | 2020-09-11 | 2020-09-11 | Composite optical parametric oscillator based on single nonlinear crystal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112271545B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113794093B (en) * | 2021-07-26 | 2022-11-25 | 中国科学院空天信息创新研究院 | Multi-wavelength Raman laser |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102214892A (en) * | 2011-05-12 | 2011-10-12 | 中国科学院理化技术研究所 | Laser based on cascade effect of bulk laser self-variable-frequency material |
| CN207352812U (en) * | 2017-01-09 | 2018-05-11 | 武汉光谷航天三江激光产业技术研究院有限公司 | A kind of changeable colour laser pen |
| CN110244498A (en) * | 2018-05-09 | 2019-09-17 | 中国科学院理化技术研究所 | Nonlinear frequency conversion crystal |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1520539A (en) * | 1967-02-14 | 1968-04-12 | Comp Generale Electricite | Optical parametric oscillator |
| US5195104A (en) * | 1991-10-15 | 1993-03-16 | Lasen, Inc. | Internally stimulated optical parametric oscillator/laser |
| JP2760302B2 (en) * | 1994-12-15 | 1998-05-28 | 日本電気株式会社 | Optical wavelength converter |
| JP2002287193A (en) * | 2001-03-23 | 2002-10-03 | Toshiba Corp | Wavelength conversion element, wavelength conversion device and laser device |
| FR2973120B1 (en) * | 2011-03-25 | 2013-03-29 | Onera (Off Nat Aerospatiale) | OPTICAL PARAMETRIC OSCILLATOR WITH NARROW CAVITIES FOR QUICK FREQUENCY SCAN |
| CN104037595B (en) * | 2014-06-20 | 2017-05-24 | 华北水利水电大学 | Terahertz wave amplifier based on optical parametric effect |
| CN106159643B (en) * | 2016-09-13 | 2019-02-22 | 华北水利水电大学 | A kind of terahertz-wave parametric oscillator based on cascade parametric effect |
| CN110244499B (en) * | 2018-05-09 | 2022-07-15 | 同方中科超光科技有限公司 | Nonlinear frequency conversion crystal |
| CN109193316B (en) * | 2018-10-11 | 2020-11-06 | 华北水利水电大学 | Multi-polarization period terahertz wave parametric oscillator |
| CN110880670A (en) * | 2019-11-29 | 2020-03-13 | 山东大学 | High-efficiency optical parametric oscillator with adjustable threshold value |
-
2020
- 2020-09-11 CN CN202010951231.6A patent/CN112271545B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102214892A (en) * | 2011-05-12 | 2011-10-12 | 中国科学院理化技术研究所 | Laser based on cascade effect of bulk laser self-variable-frequency material |
| CN207352812U (en) * | 2017-01-09 | 2018-05-11 | 武汉光谷航天三江激光产业技术研究院有限公司 | A kind of changeable colour laser pen |
| CN110244498A (en) * | 2018-05-09 | 2019-09-17 | 中国科学院理化技术研究所 | Nonlinear frequency conversion crystal |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112271545A (en) | 2021-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5400173A (en) | Tunable mid-infrared wavelength converter using cascaded parametric oscillators | |
| US5181211A (en) | Eye-safe laser system | |
| US5276548A (en) | Ring cavity optical parametric apparatus | |
| US4208636A (en) | Laser apparatus | |
| US5579152A (en) | Tunable optical parametric oscillator | |
| CN108258575B (en) | Long-wave infrared optical parametric oscillator with high conversion efficiency | |
| RU100680U1 (en) | LASER WITH OPTICAL PARAMETRIC GENERATOR | |
| US20210389644A1 (en) | Parametric Light Generation Method and Its Application | |
| CN110112642B (en) | Optical parametric oscillator | |
| US6044094A (en) | Laser system with optical parametric oscillator | |
| CN211700916U (en) | Long-wave infrared Raman laser | |
| US6295160B1 (en) | Broad tuning-range optical parametric oscillator | |
| CN112271545B (en) | Composite optical parametric oscillator based on single nonlinear crystal | |
| US5497388A (en) | Laser diode pumped solid laser | |
| JP3410108B2 (en) | A range finding system using an eye-safe laser with a Brewster angle Q-switch in a single cavity cavity of both the pump laser and the optical parametric oscillator | |
| CN105119139A (en) | Tunable single longitudinal mode 2[mu]m solid laser based on bipyramid resonant cavity | |
| US6834063B2 (en) | Efficient angle tunable output from a monolithic serial KTA optical parametric oscillator | |
| CA2366982C (en) | Monolithic serial optical parametric oscillator | |
| CN112803224A (en) | Mid-infrared band difference frequency laser based on gallium-lanthanum niobate crystal | |
| US6384973B1 (en) | Convex brewster-cut crystal for nonlinear frequency conversion | |
| KR950002068B1 (en) | Second harmonic generating system and method | |
| Shen et al. | High-power long-wave infrared laser based on polarization beam coupling technique | |
| CN1140945C (en) | Non-resonance cavity light parametric oscillator | |
| Berthomé et al. | Widely tunable LWIR parametric source based on pump wavelength tuning | |
| RU76509U1 (en) | LASER WITH OPTICAL PARAMETRIC GENERATOR |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |