JPH10254002A - Optical parametric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously generate plural-wavelength signal light beams and idler light beams by providing an optical resonator arranged to be opposed to a non-linear optical crystal excited by exciting light and equipped with an optical resonant mirror having plural reflection parts. SOLUTION: A pair of optical resonant mirrors 11 and 12 forming the optical resonator 10 respectively is arranged on both end sides of the non-linear optical crystal 1 such as a KTP, that is, in the optical axis direction of the oscillator. As for either mirror 11, two mirrors 11a and 11b are arranged at a specified angle to the optical crystal 1, that is, in a specified angle direction with respect to the optical axis direction of the oscillator, and integrated to be formed in chevron shape. The other mirror 12 is similarly formed in the chevron shape. When the optical crystal 1 is irradiated and excited by the exciting light, optical resonance is generated in plural pairs of optical resonators 10 respectively, and plural signal light beams and idler light beams having different wavelength respectively are simultaneously generated from one non-linear optical crystal 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical parametric oscillator that generates three wavelengths of excitation light, signal light, and idler light upon incidence of excitation light.

[0002]

2. Description of the Related Art FIG. 11 is a block diagram of an optical parametric oscillator. At both ends of the nonlinear optical crystal 1 such as KTP,
Each of a pair of optical mirrors 3 and 4 forming the optical resonator 2 is arranged.

The wavelength λ output from the excitation laser light source 5
_When the non-linear optical crystal 1 in the optical resonator 2 is irradiated with the excitation light of ₁ through the condenser lens system 6, the nonlinear optical crystal 1
Is excited, and optical resonance occurs between the optical mirrors 3 and 4.

[0004] The optical resonant between these optical mirrors 3,4, laser light having a wavelength lambda ₁ and the same wavelength lambda ₁ of the excitation light, the wavelength lambda ₂ of the signal light, laser light including the idler light having a wavelength lambda ₃ Output Is done.

The relationship among the wavelengths λ ₁ , λ ₂ , and λ ₃ of the laser light, the signal light, and the idler light is, for example, λ ₁ <λ ₂ <λ ₃ (1).

In such an optical parametric oscillator, in order to change the generation wavelengths λ ₂ and λ ₃ , the optical axis of the nonlinear optical crystal 1 disposed in the oscillator is rotated with respect to the optical axis of the oscillator. Can be done in, for example, IE
EE JOURNAL OF QUANTUM ELECTRONICS.VOL.QE-15, NO6, JU
NE.1979, P415.

However, in such a method of rotating the nonlinear optical crystal 1, only one optical resonator 2 can be formed for one nonlinear optical crystal 1, and the maximum of excitation light, signal light and idler light can be obtained. Only three wavelengths can be generated.

On the other hand, as another method of changing the wavelength generated by the optical parametric oscillator, a method of applying an electric field to the nonlinear optical crystal 1 and changing the electric field is disclosed in, for example, J. Opt. Soc. Am. BA10. .1659 (1993).

However, even in such a method of applying an electric field to the nonlinear optical crystal 1, one optical resonator 2 is provided for one nonlinear optical crystal 1 in the same manner as the above method.
Only a maximum of three wavelengths of excitation light, signal light and idler light can be generated.

[0010]

As described above, in the above-mentioned optical parametric oscillator, only one optical resonator 2 can be formed for one nonlinear optical crystal 1, and at the same time signal light and idlers of a plurality of wavelengths can be formed. It is difficult to generate light.

Accordingly, signal light of a plurality of wavelengths simultaneously,
In order to generate idler light, for example, a plurality of optical resonators must be formed using a plurality of nonlinear optical crystals. Therefore, an object of the present invention is to provide an optical parametric oscillator that can simultaneously generate signal light and idler light of a plurality of wavelengths.

[0012]

According to a first aspect of the present invention, there is provided an optical resonance apparatus including an optical resonance mirror having a plurality of reflection portions disposed to face a nonlinear optical crystal excited by irradiation of excitation light. It is an optical parametric oscillator provided with a device.

In such an optical parametric oscillator, when the nonlinear optical crystal is irradiated with the excitation light to be excited, optical resonance occurs in each of a plurality of pairs of optical resonators, and the wavelength of the light is increased from one nonlinear optical crystal. A plurality of different signal lights and idler lights are simultaneously generated.

According to a second aspect of the present invention, there is provided an optical resonator having an optical resonance mirror having a plurality of reflection portions disposed so as to face a nonlinear optical crystal excited by irradiation of excitation light, And a parallel optical system for converting the traveling directions of the respective lights output from the devices into the same direction.

In such an optical parametric oscillator, when the nonlinear optical crystal is irradiated with excitation light and excited, optical resonance occurs in each of a plurality of pairs of optical resonators, and wavelengths are respectively generated from one nonlinear optical crystal. Are output from the optical resonator at the same time, the signal light and the idler light are converted in the same direction by the parallel optical system.

According to a third aspect of the present invention, in the optical parametric oscillator according to the first or second aspect, the optical resonator is formed by integrating a plurality of mirrors arranged at different angles with respect to a light incident surface of the nonlinear optical crystal. The first and second optical resonance mirrors were arranged such that each of the first and second optical resonance mirrors faced each other via the nonlinear optical crystal.

With such an optical parametric oscillator, optical resonance occurs between the first and second optical resonance mirrors through the nonlinear optical crystal, and a plurality of signal lights and idler lights having different wavelengths respectively. Are output simultaneously.

According to a fourth aspect of the present invention, in the optical parametric oscillator according to the first or second aspect, the optical resonator has a transmission portion that transmits the excitation light and guides the excitation light to the nonlinear optical crystal. The first and second optical resonance mirrors in which a plurality of mirrors arranged at different angles are integrated are respectively opposed to each other via the nonlinear optical crystal. It was arranged as follows.

In such an optical parametric oscillator, the excitation light is incident on the nonlinear optical crystal through the transmission part to be excited, and the excitation of the nonlinear optical crystal causes the excitation light between the first and second optical resonant mirrors. Then, optical resonance occurs through the nonlinear optical crystal, and a plurality of signal lights and idler lights having different wavelengths are simultaneously output.

According to the fifth aspect, in the optical parametric oscillator according to the third or fourth aspect, a predetermined curvature is formed for each of the reflection sides of the first and second optical resonance mirrors for each mirror.

With such an optical parametric oscillator, a plurality of resonators constituted by mirrors are used as stable resonators, and the resonators have excellent directivity. Claim 6
According to the above, in an optical parametric oscillator in which each optical resonance mirror of an optical resonator is arranged at both ends of a nonlinear optical crystal excited by irradiation of excitation light, the excitation light and the optical resonator are arranged in the optical resonator. An optical parametric oscillator comprising: an optical system for transmitting resonance light generated between the respective optical resonance mirrors to the nonlinear optical crystal in a plurality of directions.

In such an optical parametric oscillator, when the pumping light enters the optical resonator, the pumping light becomes
Excited by entering the nonlinear optical crystal in multiple directions,
Resonant light generated between the optical resonator mirrors of the optical resonator generated by excitation of the nonlinear optical crystal is transmitted through the nonlinear optical crystal in a plurality of directions. Thereby, a plurality of signal lights and idler lights having different wavelengths are simultaneously generated.

According to a seventh aspect of the present invention, in the optical parametric oscillator according to the sixth aspect, at least two excitation light passage holes disposed between one of the optical resonance mirrors and the nonlinear optical crystal. A mask formed of
The excitation light and the resonance light generated between the optical resonance mirrors of the optical resonator are disposed between the mask and the nonlinear optical crystal and between the nonlinear optical crystal and the other optical resonance mirror, respectively. Optical lenses that transmit light in a plurality of directions.

In such an optical parametric oscillator, the excitation light passing through each through hole of the mask is incident on the nonlinear optical crystal in a plurality of directions, and is excited by the excitation light to excite the nonlinear optical crystal. The generated resonance light between the optical resonance mirrors of the optical resonator is transmitted through the nonlinear optical crystal in a plurality of directions. Thereby, a plurality of signal lights and idler lights having different wavelengths are simultaneously generated.

According to an eighth aspect, in the optical parametric oscillator according to the seventh aspect, the mask is provided so as to be movable in a direction substantially perpendicular to the optical axis direction of the optical resonator.
In such an optical parametric oscillator, the moving direction of the mask changes the incident direction of the excitation light incident on the nonlinear optical crystal, thereby changing the wavelengths of the generated signal light and idler light.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 11 are denoted by the same reference numerals. FIG. 1 is a configuration diagram of an optical parametric oscillator.

A pair of optical resonance mirrors 11 and 12 forming an optical resonator 10 are arranged on both ends of the nonlinear optical crystal 1 such as KTP, that is, in the optical axis direction of the oscillator. One of the optical resonance mirrors 11 has two mirrors 11a and 11b arranged at a predetermined angle with respect to the nonlinear optical crystal 1, that is, at a predetermined angle with respect to the optical axis direction of the oscillator. 11a and 11b are integrally formed to form a so-called "C" shape.

The other optical resonance mirror 12 has two mirrors 12a and 12b, which are located at a predetermined angle with respect to the nonlinear optical crystal 1, that is, with respect to the optical axis direction of the oscillator. The mirrors 12a and 12b are arranged in a predetermined angle direction and are integrally formed, and are formed in a so-called "C" shape.

The mirror 11a and the mirror 12b are arranged to face each other via the nonlinear optical crystal 1 to form one optical resonator, and the mirror 11b and the mirror 12a are arranged to face each other via the nonlinear optical crystal 1. Thus, another optical resonator is formed.

On the optical resonance mirror 11 side on the optical axis of the resonator, an excitation laser light source 5 for outputting excitation light of wavelength λ ₁ is provided.
Is arranged. Next, the operation of the apparatus configured as described above will be described.

When pumping light of wavelength λ ₁ is output from the pumping laser light source 5, the pumping light enters the nonlinear optical crystal 1 in the optical resonator 10. When the excitation light is incident on the nonlinear optical crystal 1, the nonlinear optical crystal 1 is excited, and the first and second optical resonant mirrors 11 and 1 of the optical resonator 10 are excited.
Optical resonance occurs between the two.

At this time, the first and second optical resonance mirrors 1
Between the mirrors 1 and 12, the mirrors 11 which are arranged facing each other
Optical resonance occurs between the mirror 11a and the mirror 12b, and optical resonance occurs between the mirror 11b and the mirror 12a.

Accordingly, one of the mirrors 11a and 12
b and the same wavelength λ as the excitation light wavelength λ ₁ due to the optical resonance between
laser beam _p1, the signal light of the wavelength lambda _s1, the laser light Q ₁ containing idler light having a wavelength lambda _i1 occurs therewith.

At the same time, due to the optical resonance between the other mirror 11b and the mirror 12a, a laser beam having the same wavelength λ _p2 as the wavelength λ ₁ of the pump light, and a signal beam having the wavelength λ _s2 ,
Laser light Q ₂ to which contains the idler light having a wavelength lambda _i2 occurs.

Here, the wavelengths of the signal light and the idler light output from the optical parametric oscillator are uniquely determined by a condition satisfying the following equation. _{1 / λ p = 1 / λ} s + 1 / λ i ... (2) k p = k s + k i ... (3) In addition, lambda is the wavelength, k is the wave number vector, p is the excitation light, s is the signal light, i Represents idler light.

Since the nonlinear optical crystal 1 has a different refractive index depending on the crystal axis, the condition of the above equation (3) changes depending on the angle between the optical axis of the optical parametric oscillator and the crystal axis, and the signal light and idler light to be output are changed. The wavelength changes.

FIG. 2 is an example in which the relationship between the wavelength of the signal light and the wavelength of the idler light when the angle of the crystal axis of the nonlinear optical crystal 1 is changed is shown for each wavelength of the excitation light. Therefore, if two or more optical resonators having a certain angle with respect to the nonlinear optical crystal 1 are formed for one nonlinear optical crystal 1, signal light and idler light of a plurality of wavelengths are generated simultaneously.

As described above, in the first embodiment, the optical resonator 10 is formed by disposing a pair of “<”-shaped optical resonance mirrors 11 and 12 at both ends of the nonlinear optical crystal 1. Therefore, signal light of a plurality of wavelengths, idler light, ie, laser light of wavelengths λ _p1 and λ _p2 , signal light of wavelengths λ _s1 and λ _s2 , wavelength λ _i1 and λ
_i2 idler light can be generated simultaneously. (2) Next, a second embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 3 is a configuration diagram of the optical parametric oscillator. A pair of optical resonance mirrors 21 and 22 forming an optical resonator 20 are arranged on both ends of the nonlinear optical crystal 1 such as KTP, that is, in the optical axis direction of the oscillator.

One of the optical resonance mirrors 21 has two mirrors 21a and 21b arranged at a predetermined angle with respect to the nonlinear optical crystal 1, that is, at a predetermined angle with respect to the optical axis direction of the oscillator. Further, a transmission portion 21c for transmitting the excitation light from the excitation laser light source 5 is formed between the mirrors 21a and 21b, and the mirrors 11a, 11b and the transmission portion 21c are integrally formed. It is formed in a shape.

The other optical resonance mirror 22, like the one optical resonance mirror 21, has the two mirrors 22a and 22b at a predetermined angle with respect to the nonlinear optical crystal 1, that is, with respect to the optical axis direction of the oscillator. The mirrors 22a, 22b and the supporting portion 22c are arranged in a predetermined angular direction and formed between the mirrors 22a and 22b, and the mirrors 22a, 22b and the supporting portion 22c are integrally formed. ing.

The mirror 21a and the mirror 22b are opposed to each other via the nonlinear optical crystal 1 to constitute one optical resonator, and the mirror 21b and the mirror 22a are opposed to each other via the nonlinear optical crystal 1. Thus, another optical resonator is formed.

Next, the operation of the device configured as described above will be described. When the excitation laser light source 5 outputs excitation light having the wavelength λ ₁ , the excitation light passes through the transmission part 21 c and enters the nonlinear optical crystal 1 in the optical resonator 10.

When the pumping light is incident on the nonlinear optical crystal 1, the nonlinear optical crystal 1 is excited, and optical resonance occurs between the first and second optical resonant mirrors 21 and 22 of the optical resonator 20. I do.

At this time, the first and second optical resonance mirrors 2
Mirrors 21 disposed opposite to each other between
Optical resonance occurs between the mirror 21a and the mirror 22b, and optical resonance occurs between the mirror 21b and the mirror 22a.

Accordingly, one of the mirrors 21a and 22
b and the same wavelength λ as the excitation light wavelength λ ₁ due to the optical resonance between
laser light _p3, which signal light having a wavelength lambda _s3, the laser light Q ₃ containing idler light having a wavelength lambda _i3 generated with.

At the same time, due to the optical resonance between the other mirror 21b and the mirror 22a, the laser light having the same wavelength λ _p4 as the wavelength λ ₁ of the excitation light, and the signal light having the wavelength λ _s4 ,
Laser light Q ₄ containing idler light having a wavelength lambda _i4 is generated.

Here, the wavelengths of the signal light and the idler light output from the optical parametric oscillator are expressed by the above equations (2) and (3).
Is uniquely determined by the condition satisfying the above.

As described above, in the second embodiment, as in the first embodiment, signal light of a plurality of wavelengths, idler light,
That is, laser light of wavelengths λ _p3 and λ _p4 , signal light of wavelengths λ _s3 and λ _s4 , and idler light of wavelengths λ _i3 and λ _i4 can be simultaneously generated. (3) Next, a third embodiment of the present invention will be described.

The first and second optical resonance mirrors 11 and 12 in the first embodiment are mirrors 11a and 1a, respectively.
Although the mirror surfaces 1b, 12a, and 12b are formed as flat surfaces, these may be formed as an optical resonance mirror 30 formed as a spherical surface having a curvature R as shown in FIG.

Similarly, the first and second optical resonance mirrors 21 and 22 of the second embodiment are
Although the mirror surfaces of 1a, 21b, 22a, and 22b are formed as flat surfaces, these may be formed as an optical resonance mirror 31 formed as a spherical surface having a curvature R as shown in FIG. In addition, 32 is a transmission part.

In the case of an optical parametric oscillator that constitutes an optical resonator in which the optical resonant mirrors 30 and 31 formed on a spherical surface having such a curvature R are arranged, a plurality of optical resonators, for example, in the first embodiment described above. The optical resonator constituted by each of the mirrors 11a and 12b and the optical resonator constituted by each of the mirrors 11b and 12a can be each a stable resonator, and can be a resonator having excellent directivity. . (4) Next, a fourth embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 is a configuration diagram of the optical parametric oscillator. In this optical parametric oscillator, a triangular prism 40 is arranged on the optical path on the output side of the optical resonator 10.

The triangular prism 40 has a function as a parallel optical system that changes the traveling direction of each light output from the optical resonator 10 in the same direction, that is, in parallel. Next, the operation of the apparatus configured as described above will be described.

When pumping light of wavelength λ ₁ is output from the pumping laser light source 5, the pumping light enters the nonlinear optical crystal 1 in the optical resonator 10. When the excitation light is incident on the nonlinear optical crystal 1, the nonlinear optical crystal 1 is excited, and the first and second optical resonant mirrors 11 and 1 of the optical resonator 10 are excited.
Optical resonance occurs between the two.

At this time, the first and second optical resonance mirrors 1
Between the mirrors 1 and 12, the mirrors 11 which are arranged facing each other
Optical resonance occurs between the mirror 11a and the mirror 12b, and optical resonance occurs between the mirror 11b and the mirror 12a.

Therefore, one of the mirrors 11a and 12
b and the same wavelength λ as the excitation light wavelength λ ₁ due to the optical resonance between
laser beam _p1, the signal light of the wavelength lambda _s1, the laser light Q ₁ containing idler light having a wavelength lambda _i1 occurs therewith.

At the same time, due to the optical resonance between the other mirror 11b and the mirror 12a, the laser light having the same wavelength λ _p2 as the wavelength λ ₁ of the pump light, and the signal light having the wavelength λ _s2 ,
Laser light Q ₂ to which contains the idler light having a wavelength lambda _i2 occurs.

Here, the wavelengths of the signal light and the idler light output from the optical parametric oscillator are expressed by the above equations (2) and (3).
Is uniquely determined by the condition satisfying the above.

The laser light having the wavelength λ _p1 , the signal light having the wavelength λ _s1 , the laser light Q ₁ including the idler light having the wavelength λ _i1 , the laser light having the wavelength λ p2, the laser light having the wavelength λ
s2 of the signal light, the laser light Q ₂ to which contains the idler light having a wavelength λi2 respectively incident on the triangular prism 40, wherein the orientation is convert each traveling direction into parallel light to the same direction.

As described above, in the fourth embodiment, the triangular prism 40 is provided on the optical path on the subsequent stage of the optical resonator 10.
Λ _p1 , λ _p2 laser light, wavelength λ _s1 , λ _s2 signal light, wavelength λ _i1 , λ _i2 idler light can be generated at the same time, and these wavelength λ _p1 laser light, wavelength λ _s1 signal light, laser light Q ₁ including idler light of wavelength λ _i1 , and laser light of wavelength λp2, wavelength λ
s2 of the signal light, the laser light Q ₂ to which contains the idler light wavelength λi2 the traveling direction can be parallel light and identical to each other, these laser light, the signal light, to utilize idler light and convenient Become.

In the fourth embodiment, the triangular prism 40 is disposed downstream of the optical resonator 10. However, instead of the triangular prism 40, another lens is used instead of the triangular prism 40, and the laser light, the signal light, and the idler are used. The light may be parallel light having the same traveling direction. (5) Next, a fifth embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals.

FIG. 7 is a configuration diagram of the optical parametric oscillator. A pair of optical resonance mirrors 51 and 52 forming an optical resonator 50 are arranged on both ends of the nonlinear optical crystal 1, that is, in the optical axis direction of the oscillator.

In the optical resonator 50, a mask 53 and two optical lenses 54 and 55 are arranged. The mask 53 is disposed between one of the optical resonance mirrors 51 and the nonlinear optical crystal 1, and as shown in FIG.
57 are formed.

In this mask 53, two passing holes (hereinafter, referred to as holes) 56 and 57 are for transmitting one or both of signal light and idler light, and the other portion 58 is for only exciting light. It is transparent.

The mask 53 is composed of a dielectric multilayer film as an optical material. One optical lens 54
Is disposed between the mask 53 and the nonlinear optical crystal 1, and the other optical lens 55 is disposed between the nonlinear optical crystal 1 and the other optical resonance mirror 52.

The optical lenses 54 and 55 transmit the excitation light and the resonance light generated between the optical resonance mirrors 51 and 52 of the optical resonator 50 to the nonlinear optical crystal 1 in a plurality of directions, here, two directions. It has a function to make it work.

Next, the operation of the device configured as described above will be described. When the excitation laser light source 5 outputs excitation light having the wavelength λ ₁ , the excitation light enters the optical resonator 50, passes through the mask 53, and enters the nonlinear optical crystal 1.

When the excitation light enters the nonlinear optical crystal 1 as described above, the nonlinear optical crystal 1 is excited, and optical resonance occurs between the first and second optical resonant mirrors 21 and 22 of the optical resonator 50. I do.

At this time, the first and second optical resonance mirrors 5
1 and 52, an optical path 58 that passes through the hole 57 of the mask 53, passes through the optical lenses 54 and 55 at a predetermined angle with respect to the nonlinear optical crystal 1, and passes through the hole 56 of the mask 53 and passes through each optical lens. Optical resonance occurs in an optical path 59 that passes through the optical fibers 54 and 55 at a predetermined angle with respect to the nonlinear optical crystal 1.

[0071] Thus, the laser beam of the same wavelength lambda _p5 and the wavelength lambda ₁ of the excitation light by the light resonating in the optical path 58, which together with a wavelength lambda _s5 of the signal light, the laser light Q ₅ containing idler light having a wavelength lambda _i5 Occur.

On the other hand, a laser beam having the same wavelength λ _p6 as the wavelength λ ₁ of the pumping light due to the optical resonance in the optical path 59, and the wavelength λ
Signal light _s6, the laser light Q ₆ is generated that contains the idler light having a wavelength lambda _i6.

The two laser beams Q ₅ and Q ₆
Are output as parallel lights having the same traveling direction. As described above, the wavelengths of the signal light and the idler light output from the optical parametric oscillator are uniquely determined by the conditions satisfying the above equations (2) and (3).

As described above, in the fifth embodiment, the excitation light passing through the holes 56 and 57 of the mask 53 is incident on the nonlinear optical crystal 1 from two directions, and the excitation light of the nonlinear optical crystal 1 is excited. Is transmitted through the nonlinear optical crystal 1 from two directions between the optical resonance mirrors 51 and 52 of the optical resonator generated by the above, so that the operation is equivalent to providing two optical resonators. And a plurality of signal lights and idler lights having different wavelengths can be simultaneously generated. (6) Next, a sixth embodiment of the present invention will be described.
The same parts as those in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 9 is a configuration diagram of an optical parametric oscillator. In the optical resonator 50, a mask 53 and two triangular lenses 60 and 61 are arranged.

One triangular lens 60 is disposed between the mask 53 and the nonlinear optical crystal 1, and the other triangular lens 61
Is disposed between the nonlinear optical crystal 1 and the other optical resonance mirror 52.

The triangular lenses 60 and 61 have a function of transmitting excitation light and resonance light generated between the optical resonance mirrors 51 and 52 of the optical resonator 50 to the nonlinear optical crystal 1 in a plurality of directions. ing.

Next, the operation of the device configured as described above will be described. When the excitation laser light source 5 outputs excitation light having the wavelength λ ₁ , the excitation light enters the optical resonator 50, passes through the mask 53, and enters the nonlinear optical crystal 1.

When the pumping light enters the nonlinear optical crystal 1 as described above, the nonlinear optical crystal 1 is excited, and optical resonance occurs between the first and second optical resonant mirrors 21 and 22 of the optical resonator 50. I do.

At this time, the first and second optical resonance mirrors 5
1 and 52, an optical path 62 that passes through the hole 57 of the mask 53 and passes through the triangular lenses 60 and 61 at a predetermined angle to the nonlinear optical crystal 1 and a hole 56 of the mask 53 and passes through each of the triangular lenses Optical resonance occurs in the optical path 63 passing through the nonlinear optical crystal 1 at a predetermined angle through 60 and 61.

[0081] Thus, the laser beam of the same wavelength lambda _p5 and the wavelength lambda ₁ of the excitation light by the light resonating in the optical path 62, which together with a wavelength lambda _s5 of the signal light, but including the idler light having a wavelength lambda _i5 laser beam Q ₅ Occur.

On the other hand, a laser beam having the same wavelength λ _p6 as the wavelength λ ₁ of the excitation light due to the optical resonance in the optical path 63, and the wavelength λ
Signal light _s6, the laser light Q ₆ is generated that contains the idler light having a wavelength lambda _i6.

The two laser beams Q ₅ and Q ₆
Are output as parallel lights having the same traveling direction. As described above, the wavelengths of the signal light and the idler light output from the optical parametric oscillator are uniquely determined by the conditions satisfying the above equations (2) and (3).

As described above, in the sixth embodiment, similar to the fifth embodiment, the same operation as the case where two optical resonators are provided can be performed, and the wavelengths differ from each other. A plurality of signal lights and idler lights can be generated simultaneously. (7) Next, a seventh embodiment of the present invention will be described.

FIG. 10 is a configuration diagram of an optical parametric oscillator. This optical parametric oscillator has a configuration in which the mask 53 is movable in a direction substantially perpendicular to the optical axis of the optical resonator 50 (direction of arrow A) in the fifth embodiment.

In such a configuration, if the excitation light of wavelength λ ₁ is output from the excitation laser light source 5 before the movement of the mask 53 as shown in FIG. Then, the light enters the nonlinear optical crystal 1 through the mask 53.

When the excitation light enters the nonlinear optical crystal 1 as described above, the first and second optical resonance mirrors 5
Laser light of the same wavelength lambda _p5 and the wavelength lambda ₁ of the excitation light by the light resonating in the optical path 58 between the 1, 52, the laser light Q ₅ containing together with the signal light of _s5 wavelength lambda, the idler light having a wavelength lambda _i5 This Occurs.

At the same time, the first and second optical resonance mirrors 5
Due to the optical resonance in the optical path 59 between 1 and 52, the laser light Q _{6 including the} laser light having the same wavelength λ _p6 as the wavelength λ ₁ of the excitation light, the signal light having the wavelength λ _s6 , and the idler light having the wavelength λ _i6. Occurs.

Here, when the mask 53 is moved upward, for example, in the drawing, the angle of the light transmitted through the nonlinear optical
That is, the angle of the transmitted light with respect to the optical axis of the nonlinear optical crystal 1 changes.

As described above, when the angle of the transmitted light with respect to the optical axis of the nonlinear optical crystal 1 changes, signal light and idler light generated in the optical path 58 between the first and second optical resonance mirrors 51 and 52. _Are changed to λ _s7 and λ _i7 , respectively. The laser light having the same wavelength λ _p7 as the wavelength λ _{1 of the} pump light does not change.

At the same time, the first and second optical resonance mirrors 5
Signal light generated in the optical path 59 between the first and the 52,
The wavelength of the idler light changes to λ _s8 and λ _i8 , respectively. The laser light having the same wavelength λ _p8 as the wavelength λ _{1 of the} pump light does not change.

As described above, in the seventh embodiment, by moving the mask 53, the angle of the transmitted light with respect to the optical axis of the nonlinear optical crystal 1 is changed, and the wavelengths of the signal light and the idler light are changed. Can be changed respectively.

[0093]

As described in detail above, claims 1 to 5 of the present invention.
According to 8, an optical parametric oscillator that can simultaneously generate signal light and idler light of a plurality of wavelengths can be provided.
Further, according to claims 2 to 8 of the present invention, there is provided an optical parametric oscillator which can simultaneously generate signal lights and idler lights of a plurality of wavelengths and can output these signal lights and idler lights as parallel lights having the same traveling direction. Can be provided.

Further, according to the seventh and eighth aspects of the present invention, there is provided an optical parametric oscillator which can simultaneously generate signal light and idler light of a plurality of wavelengths and can change the wavelength of these signal light and idler light. it can.

[Brief description of the drawings]

FIG. 1 shows a first example of an optical parametric oscillator according to the present invention.
FIG. 1 is a configuration diagram showing an embodiment.

FIG. 2 is a diagram showing the relationship between the wavelengths of signal light and idler light when the angle of the nonlinear optical crystal is changed.

FIG. 3 shows a second example of the optical parametric oscillator according to the present invention.
FIG. 1 is a configuration diagram showing an embodiment.

FIG. 4 is a diagram showing a spherical optical resonance mirror having a curvature.

FIG. 5 is a diagram showing a spherical optical resonance mirror having a curvature.

FIG. 6 shows a fourth example of the optical parametric oscillator according to the present invention.
FIG. 1 is a configuration diagram showing an embodiment.

FIG. 7 shows a fifth example of the optical parametric oscillator according to the present invention.
FIG. 1 is a configuration diagram showing an embodiment.

FIG. 8 is a configuration diagram of a mask.

FIG. 9 shows an optical parametric oscillator according to a sixth embodiment of the present invention.
FIG. 1 is a configuration diagram showing an embodiment.

FIG. 10 is a diagram showing an operation when the mask is moved.

FIG. 11 is a configuration diagram of a conventional optical parametric oscillator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Nonlinear optical crystal, 5 ... Excitation laser light source, 10, 20 ... Optical resonator, 11, 12, 21, 22 ... Optical resonance mirror, 11a, 11b, 12a, 12b ... Mirror, 21a, 21b, 22a, 22b Mirrors 30, 31 First and second optical resonance mirrors 40 Triangular prisms 50 Optical resonators 51 52 Optical resonance mirrors 53 Masks 54 and 55 Optical lenses 56 and 57 ... Hall, 60,61 ... Triangular prism.

Claims (8)

[Claims] 1. An optical parametric device comprising: an optical resonator including an optical resonant mirror having a plurality of reflection portions disposed so as to face a nonlinear optical crystal excited by irradiation of excitation light. Oscillator. 2. An optical resonator having an optical resonant mirror having a plurality of reflection portions disposed opposite to a nonlinear optical crystal excited by irradiation with excitation light, and an optical resonator output from the optical resonator. An optical parametric oscillator, comprising: a parallel optical system that converts a traveling direction of each light into the same direction. 3. The optical resonator according to claim 1, wherein the first and second optical resonance mirrors are formed by integrating a plurality of mirrors arranged at different angles with respect to a light incident surface of the nonlinear optical crystal. 3. The optical parametric oscillator according to claim 1, wherein each of the second optical resonance mirrors is arranged so as to face each other via the nonlinear optical crystal. 4. The optical resonator has a transmission part that transmits the excitation light and guides the excitation light to the nonlinear optical crystal, and integrates a plurality of mirrors arranged at different angles with respect to the transmission part. 2. The first and second optical resonance mirrors are arranged such that each of the first and second optical resonance mirrors faces each other via the nonlinear optical crystal. Or the optical parametric oscillator according to 2. 5. The optical parametric oscillator according to claim 3, wherein a predetermined curvature is formed on each of the reflection sides of the first and second optical resonance mirrors for each of the mirrors. 6. An optical parametric oscillator in which respective optical resonance mirrors of an optical resonator are disposed at both ends of a nonlinear optical crystal which is excited by irradiation with excitation light, wherein the optical resonator is disposed in the optical resonator, and An optical parametric oscillator, comprising: an optical system that transmits resonance light generated between the optical resonance mirrors of the optical resonator to the nonlinear optical crystal in a plurality of directions. 7. A mask provided with at least two holes for passing said excitation light disposed between one of said optical mirrors and said nonlinear optical crystal, and said mask and said nonlinear optical crystal And between the nonlinear optical crystal and the other of the optical mirror, respectively,
7. An optical lens for transmitting the excitation light and resonance light generated between the optical resonance mirrors of the optical resonator to the nonlinear optical crystal in a plurality of directions. An optical parametric oscillator as described. 8. The optical parametric oscillator according to claim 7, wherein said mask is provided so as to be movable in a direction substantially perpendicular to an optical axis direction of said optical resonator.