JPH0677577A - Tunable solid laser - Google Patents

Abstract

PURPOSE:To lessen a deterioration with age add an optical deterioration, which is generated in a working atmosphere, and to markedly facilitate the handling of a tunable solid laser by a method wherein a solid element is used for all of a laser oscillation medium, the wavelength shift medium of a wavelength extension device and the like. CONSTITUTION:A Ti:Sapphire laser is used for a tunable solid laser 1, two BBO (beta-BaB2O4) crystals are used for a non-linear optical crystal of a wavelength extension device 2, an Nd:YAG laser is used for a solid laser 3 and five sheets of mirrors are used for a delay optical system 4 to generate ultraviolet rays to near infrared rays. As a result, laser beams of wavelengths of 780, 613, 448, 389 and 316nm are obtained in each wavelength mixing system. As shown in the above, a laser oscillation to cover a wide region ranging from an ultraviolet region to an infrared region becomes possible safely and easily by a small-scale device without needing equipments in a tunable solid laser.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunable solid-state laser device. More specifically, the present invention relates to a wavelength tunable solid-state laser device using a solid-state element for a laser oscillator, an amplifier and a wavelength extension device.

[0002]

2. Description of the Related Art At present, wavelength tunable lasers include dye lasers and semiconductor lasers. The semiconductor laser has a laser light oscillation region mainly in the infrared region.
It is a near-infrared region and the variable wavelength region is not so wide. On the other hand, the dye laser has an average variable wavelength range of about 50 nm when one dye is used.
By using several kinds of dyes, it is possible to cause laser oscillation in the wavelength range from ultraviolet to near infrared. Therefore, the most popular tunable laser is the dye laser.

The dye laser is used by putting an organic dye solution in a liquid state (gas state) in a transparent glass cell as an oscillation medium. However, such a method of use has the following problems. First, optical degradation of the dye occurs, that is, the service life is short. Secondly, since it is mainly used in the liquid state, the organic dye must be dissolved in various solvents before use. As the solvent, methyl alcohol, ethyl alcohol, dioxane, etc., which are generally dangerous substances and have high volatility, are used, so that they may catch fire or ignite. Third, since organic dyes are harmful substances, when using dye lasers,
There are various restrictions on the storage and management of organic dyes and solvents, the treatment of deteriorated dye waste liquids, and the places where lasers are used. In addition, an additional equipment such as a circulation device for circulating the dye solution and a cooling device for cooling the dye is required, resulting in a large-scale and expensive system.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a wavelength tunable solid-state laser device which solves the various problems in the prior art.

[0005]

As a result of earnest research to achieve this object, the inventor of the present application has found that solid-state elements are used for all of the laser oscillation medium, the wavelength conversion medium of the wavelength expansion device, and the like. Extremely low optical deterioration caused by changes and use environment, extremely easy to handle,
The inventors have invented a tunable solid-state laser device of the present invention that is compact and highly safe.

FIG. 1 shows a tunable solid-state laser device of the present invention.
It will be specifically described by. The tunable solid-state laser device of the present invention comprises a tunable solid-state laser 1, a wavelength expansion device 2 for converting laser light generated by the laser 1 into different wavelengths using a nonlinear optical crystal, and the wavelength expansion by exciting the laser 1. A solid-state laser 3 for generating laser light necessary for wavelength mixing in the device 2, and an optical delay using a plurality of optical systems when the light generated by the laser 3 is supplied to the wavelength expansion device 2. It is composed of a delay optical system 4 and a total reflection mirror 5 for carrying a laser beam.

The configuration of the wavelength extension device 2 in the present invention will be specifically described with reference to FIG. This wavelength extension device is mainly composed of a non-linear optical crystal, and generates light in the ultraviolet to visible light region by several different wavelength mixing systems.

Thus, as a nonlinear optical crystal, BBO
(Β-BaB ₂ O ₄ ), KDP (KH ₂ PO ₄ ), KD
^* P (KD ₂ PO ₄ ), LBO (LiB ₃ O ₅ ), KT
P (KTiOPO ₄ ), LiNbO ₃ , KNbO ₃ , A
_{DP (NH 4 H 2 PO 4} ), UREA (Co (NH 2)
₂ ) and LAP ((NH ₂ ) ₂ CHN (CH ₂ ) ₃ C
H (NH ₃ ) COO.H ₂ PO ₄ ) or the like is used.

As shown in FIG. 2, this apparatus includes shutters 11 and 11 ', nonlinear optical crystals 12 and 13, and a compensator 1 for correcting the propagation direction of laser light.
4, a dichroic mirror 15 for combining the solid-state laser light and the wavelength tunable laser light or the light wavelength-converted by the wavelength expansion device 2 to propagate in the same direction, and total reflection mirrors 16 and 16 'for carrying the laser light. Solid-state laser fundamental wave transmitting 17, second harmonic transmitting filter 18 and 18 ', nonlinear optical crystal 12
And a rotation stage 19 for rotating 13, a wavelength plate 20 for rotating the polarization direction of the solid-state laser light used for wavelength mixing by 90 degrees, and for setting an optical element in an arbitrary state in each wavelength mixing method. Translation stage 21, perell blocker (PELLIN-BROCA) for reflecting light after wavelength conversion in one direction
The prism 22 and the rotary stage 19 and 21 are composed of a stage 23 for rotating the stage by 90 °.

Next, a method of generating laser light in the near infrared to ultraviolet region by using two nonlinear optical crystals BBO in this wavelength extension device will be described. Each wavelength mixing method is shown below. 1) Generation of laser light in the near infrared light region. It is generated by a wavelength tunable laser oscillator. In FIG. 3, the shutter 11 is open and 11 'is closed (blocks light), and the thick line indicates the path of light. 2) Generation of laser light in the infrared to visible light region. The laser light generated by the wavelength tunable laser is converted into laser light (second high frequency) having a half wavelength using the nonlinear optical crystal 12. After combining this light and the fundamental wave of the solid-state laser,
Difference frequency mixing is performed using the nonlinear optical crystal 13. In FIG. 4, the shutters 11 and 11 'are both open, and the thick line indicates the path of light. 3) Generation of laser light in the visible light region. After combining the laser light generated by the wavelength tunable laser and the fundamental wave of the solid-state laser, the nonlinear optical crystal 12 is used to perform sum frequency mixing.
In FIG. 5, the shutters 11 and 11 'are both open, and the thick line indicates the path of light. 4) Generation of laser light in the ultraviolet light to visible light region. The laser light generated by the wavelength tunable laser is converted into a laser light having a half wavelength and a second high frequency by using a nonlinear optical crystal. In FIG. 6, the shutter 11 is open and 11 'is closed (blocks light), and the thick line indicates the path of light. 5) Generation of laser light in the ultraviolet region. After the laser light generated by the wavelength tunable laser and the second harmonic of the solid-state laser are combined, the nonlinear optical crystal 12 is used to perform sum frequency mixing. In FIG. 7, both shutters 11 and 11 'are open, and the thick line indicates the path of light. 6) Generation of laser light in the ultraviolet region. After the laser light generated by the wavelength tunable laser is converted into laser light having a half wavelength using the nonlinear optical crystal 12, the nonlinear optical crystal 13 is used to generate the third high frequency. In FIG. 8, the shutter 11 is open and 11 'is closed (blocks light),
The thick line indicates the path of light.

[0011]

EXAMPLES The experiment was carried out using the apparatus shown in FIG. A Ti: Sapphire laser is used for the variable wavelength solid-state laser 1, two BBOs are used for the nonlinear optical crystal of the wavelength extension device 2, and an Nd: YAG laser is used for the solid-state laser 3.
The delay optical type 4 uses five total reflection mirrors to
Generated near infrared light. As a result, in the above six methods, 780, 613, 448, 389, 316n respectively.
m laser light was obtained. As described above, the tunable solid-state laser device of the present invention can safely and easily oscillate a laser in a wide range from ultraviolet to infrared with a small-scale device without the need for additional equipment.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a wavelength tunable solid-state laser device of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a wavelength extension device according to the present invention.

FIG. 3 is an explanatory diagram of laser light generation in a near infrared light region when two nonlinear optical crystals BBO are used in the wavelength extension device according to the present invention.

FIG. 4 is an explanatory diagram of laser light generation in the near infrared to visible light region when two nonlinear optical crystals BBO are used in the wavelength extension device according to the present invention.

FIG. 5 is an explanatory diagram of laser light generation in a visible light region when two nonlinear optical crystals BBO are used in the wavelength extension device according to the present invention.

FIG. 6 is an explanatory diagram of laser light generation in the ultraviolet light to visible light region when two nonlinear optical crystals BBO are used in the wavelength extension device in the present invention.

FIG. 7 is an explanatory diagram of laser light generation in the ultraviolet light region when two nonlinear optical crystals BBO are used in the wavelength extension device of the present invention.

FIG. 8 is an explanatory diagram of laser light generation in an ultraviolet light region in another mode when two nonlinear optical crystals BBO are used in the wavelength extension device according to the present invention.

[Explanation of symbols]

 1 Tunable solid-state laser 2 Wavelength extender 3 Solid-state laser 4 Delay optical system 5 Total reflection mirror 11 Shutter 11 'Shutter 12 Non-linear optical crystal 13 Non-linear optical crystal 14 Compensator 15 Dichroic mirror 16 Total reflection mirror 16' Total reflection mirror 17 Filter 18 Filter 19 Rotating Stage 20 Wave Plate 21 Translation Stage 22 Perim Blocker Prism 23 90 ° Rotating Stage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Arisawa 4-4, Shirane, Shikata, Tokai-mura, Naka-gun, Ibaraki Japan Atomic Energy Research Institute Tokai Research Institute

Claims (4)

[Claims] 1. A wavelength tunable laser oscillator comprising a laser oscillator, a laser amplifier, and a wavelength extender,
The laser oscillator comprises a tunable solid-state laser, the laser amplifier comprises a tunable solid-state laser medium,
The wavelength tunable solid-state laser device, wherein the wavelength expansion device comprises a nonlinear optical crystal. 2. The non-linear optical crystal is BBO (β-BaB ₂
O ₄ ), KDP (KH ₂ PO ₄ ), KD ^* P (KD ₂ P
O ₄ ), LBO (LiB ₃ O ₅ ), KTP (KTiOP
O ₄ ), LiNbO ₃ , KNbO ₃ , ADP (NH ₄ H
_{2 PO 4), UREA (Co} (NH 2) 2) and LA
_{P ((NH 2) 2 CHN} (CH 2) 3 CH (NH 3) C
The wavelength tunable laser device according to claim 1, which is selected from the group consisting of OO.H ₂ PO ₄ ). 3. The non-linear optical crystal used is one or two.
The tunable solid-state laser device according to claim 1, wherein the number of the tunable solid-state laser devices is one or more. 4. A wavelength tunable solid-state laser, a wavelength expansion device for converting laser light generated by the laser into different wavelengths by using a non-linear optical crystal, and necessary for exciting the laser and wavelength mixing by the wavelength expansion device. A solid-state laser for generating a laser beam, a delay optical system for performing optical delay by using a plurality of optical systems when supplying the light generated by the solid-state laser to the wavelength extension device, and a total for carrying the laser beam Tunable solid-state laser device consisting of a reflecting mirror.