JP2000349380A - Dye laser, and method of adjusting optical axis of the dye laser beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance accuracy in adjustment, and obtain a highly efficient dye laser as a result by performing the adjustment of the optical axis of a dye laser beam not with a pilot beam but with an actual dye laser beam. SOLUTION: This device is equipped with a dye multistage amplifier 100, where one coloring matter laser oscillator 3 and at least two dye laser amplifiers 4, 5, and 6 are connected in series, a solid-state laser device 1 which emits a laser beam for excitation so as to excite each dye laser amplifier 3, 5, and 6, an optical fiber 2 which transmits the laser beam for excitation emitted by this solid-state laser device 1 to the dye laser amplifiers 4, 5, and 6, a shut-off means 14 which is provided between this solid-state laser device 1 and the dye laser multistage amplifier 100 and intercepts the laser beam for excitation, and an opening and closing controller 17 which controls the opening and closing of the shut-off means 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye laser apparatus which can be used for laser isotope separation or the like and which can adjust the wavelength with high power, and a method for adjusting the optical axis of the dye laser beam.

[0002]

2. Description of the Related Art As a laser device used for laser isotope separation, a dye laser device capable of wavelength adjustment is employed because it is necessary to precisely tune to a wavelength specific to a target isotope. In addition, high beam quality such as narrow spectrum width and small wavefront distortion is required, and high power of several kW is required for a system intended for commercial use. For this reason, in a dye laser device used for laser isotope separation, a dye laser oscillator that generates a high-quality beam and a plurality of dye laser amplifiers that sequentially amplify the beam with high power are connected in series. Dye laser multi-stage amplifier (English abbreviation:
DL-MOPA (Dye Laser Master Oscillator Power
Amplifiers)). Further, the dye laser device is a laser device of a type that oscillates and amplifies a laser by optical excitation. Therefore, a laser device for excitation is separately required. As the excitation laser device, a copper vapor laser device,
A laser device employing a solid-state laser device has been proposed.

FIG. 7 is a schematic diagram of a conventional dye laser apparatus for isotope separation described in, for example, JP-A-5-218540. This dye laser device includes one dye laser oscillator 3 and three dye lasers 3 connected to the dye laser oscillator 3.
Dye laser amplifiers 4, 5, and 6 in stages, a solid-state laser device 1 as an excitation laser device for exciting each of the dye laser amplifiers 4, 5, and 6, and an excitation laser emitted from the solid-state laser device 1 The beam is directed to each dye laser amplifier 4, 5,
And an optical fiber 2 for transmitting up to 6.
The optical fiber 2 has a core diameter of, for example, 0.4 mm to 1.0 mm.
0 mm. A dye laser oscillator 3, a first-stage dye laser amplifier 4, a second-stage dye laser amplifier 5, and a third-stage dye laser amplifier 6 are connected in series to form a dye laser multi-stage amplifier (DL-MOPA). Is composed. The solid-state laser device 1 uses a neodymium-doped YAG (structural formula: Y ₃ Al ₅ O ₁₂ ) crystal as a laser medium, and generates a beam called a fundamental wave having a wavelength of 1064 nm by exciting the crystal with a semiconductor laser. Further, the fundamental frequency beam is doubled by using an optical crystal such as KTP (structural formula: KTiOPO ₄ ) to double the optical frequency, that is, to reduce the wavelength to 532n.
It is converted to m and emitted. Dye laser oscillator 3
Has a wavelength selecting element such as an etalon inside, and generates a high-quality dye laser beam having a low power (1 W or less) but a wavelength controlled with high precision.
7a is a dye laser beam emitted from the dye laser oscillator 3, 7b is a dye laser beam amplified by the first dye laser amplifier 4, and 7c is a dye laser amplified by the second dye laser amplifier 5. The beam 7d is a dye laser beam amplified by the dye laser amplifier 6 in the third stage.

FIG. 8 is an enlarged view of a main part of the dye laser amplifier 6 at the third stage. Other dye laser amplifiers 4,
5 has a similar structure. In FIG. 8, reference numeral 8 denotes a dye cell. Inside the dye cell 8, a flow channel 8a through which a dye solution 9 flows is provided. The flow channel 8a of the dye cell 8, the optical fiber 2, and the dye laser beam 7c Are orthogonal to each other. The excitation laser beam emitted from the optical fiber 2 is absorbed by the dye solution 9 flowing in the channel 8 a of the dye cell 8. The dye molecules that have absorbed the excitation laser beam transition from the ground state to the excited state. When the dye solution 9 is passed through the dye laser beam 7c propagating from the dye laser amplifier 5 at the preceding stage, the dye molecules return from the excited state to the ground state and amplify the dye laser beam 7c. In other words, the power of the excitation laser beam is converted to the power of the dye laser beam. This phenomenon is commonly called stimulated emission,
This is the basic principle of laser. The power of the dye laser beam 7d emitted from the dye laser amplifier 6 is large, but the quality of the beam, such as the wavelength and the wavefront, is the same as that of the incident dye laser beam 7c, and the change is not changed. Absent.

In the dye laser device having the above configuration, first, a beam having a wavelength of 532 nm is emitted from the solid-state laser device 1. This beam is called a second harmonic with respect to the fundamental wave, and is used as an excitation laser beam for the dye laser oscillator 3 and the dye laser oscillators 4, 5, and 6. The power of the excitation laser beam output from one solid-state laser device 1 is 30 to 50 W. A plurality of solid-state laser devices 1 are operated in parallel according to the required power. The excitation laser beam output from each solid-state laser device 1 is transmitted to the dye laser oscillator 3 and each of the dye laser amplifiers 4, 5, and 6 by the optical fiber 2. The dye laser oscillator 3 generates a high-quality dye laser beam whose wavelength is controlled with high precision. This dye laser beam is sequentially amplified through a first-stage dye laser amplifier 4, a second-stage dye laser amplifier 5, and a third-stage dye laser amplifier 6, and finally has a high power of several kW. And is emitted as a dye laser beam 7d.

The dye laser amplifying devices 4, 5, 6
In order for amplification to be performed with high efficiency, it is necessary to use the excited dye molecules without waste. For this reason,
Ideally, the dye laser beam 7c passes through the entire dye solution 9 irradiated with the excitation laser beam.
However, when the dye laser beam 7c collides with the inner wall of the flow channel 8a of the dye cell 8, the cross-sectional power distribution of the dye laser beam is distorted due to the diffraction phenomenon, and the propagation characteristics thereafter deteriorate, and the dye laser beam cannot reach far. Problems arise.

FIG. 9 shows a sectional power distribution when the dye laser beam does not hit the inner wall of the flow channel 8a.
Has an averaged power up to the vicinity of the left and right inner walls. On the other hand, FIG. 10 shows a cross-sectional power distribution when the dye laser beam collides with the inner wall of the flow channel, and the shape of the cross-sectional power distribution of the laser beam on the hit side is distorted.

For example, in the dye laser amplifier 6 at the third stage, the dye solution 9 is irradiated with the excitation laser beam 12 and the dye laser beam 7c is generated despite the dye molecules being in an excited state. If not incident, stimulated emission is induced using spontaneous emission light as a seed, and ASE (Amplif
Unwanted light called ied Spontaneous Emission (hereinafter referred to as
(Abbreviated as ASE) throughout the entire specification. This ASE is also generated in the direction opposite to the original dye laser beam propagation direction, that is, toward the second stage dye laser amplifier 5. This ASE is amplified by the second-stage dye laser amplifier 5 and further flows back to the first-stage dye laser amplifier 4. The ASE is amplified by the dye laser amplifier 4 in the first stage, and the dye laser oscillator 3
Backflow until Since the ASE having a power several tens to several hundreds times higher than the original dye laser beam is incident on the dye laser oscillator 3 and the first-stage amplifier 4, there is a possibility that the optical components may be burned.

For this reason, the optical axis adjustment work for precisely matching the width and the position of the dye laser beam 7c with the flow path 8a is a very important work for increasing the efficiency of the entire dye laser device. As a specific example of this optical axis adjustment, as shown in FIG. 7, with the solid-state laser device 1 stopped, a low power (several to several tens mW) like a helium neon laser device 18 is used instead of the dye laser beam 7a. The light beam emitted from the alternative light source is used as the pilot beam 19 and propagated along the passage of the dye laser beam 7a to adjust the optical axis of the dye laser beam. The pilot beam 19 is adjusted so as to be coaxial with the dye laser beam 7a emitted from the dye laser oscillator 3, and its cross-sectional power distribution is near the center of the flow path 8a in the width direction as shown in FIG. And has a peak at which the value is substantially zero near the inner wall of the flow channel 8a.

[0010]

In the conventional dye laser device, the optical axis of the dye laser beam is adjusted by using the pilot beam 19 of the alternative light source without using the actual dye laser beams 7a to 7c. However, as shown in FIGS. 9 and 11, the cross-sectional power distribution of the dye laser beam 7c is different from the power distribution of the pilot beam 19, and furthermore, as the dye laser amplifiers 4, 5, and 6 sequentially excite the dye laser beam 7c. The power distribution changes.
Therefore, in the operation of adjusting the optical axis of the dye laser beam by the pilot beam 19, the dye laser beams 7a to 7c cannot be precisely adjusted to pass near the wall of the flow path 8a of the dye cell 8, and as a result, the dye laser There is a problem that the efficiency of the device is reduced.

It is also difficult to perform fine adjustment using the actual dye laser beam after adjusting the optical axis of the dye laser beam with the pilot beam 19. The reason is that the optical axis of the dye laser beam 7a entering the first-stage dye laser amplifier 4 is moved by adjusting an optical system such as a mirror between the dye laser oscillator 3 and the dye laser amplifier 4. This is because the incident positions of the dye laser beams 7b and 7c in the second-stage dye laser amplifier 5 and the third-stage dye laser amplifier 5 necessarily fluctuate, so that the above-described reverse flow of the ASE occurs.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is possible to more precisely adjust the optical axis using an actual dye laser beam, and as a result, to reduce the output efficiency. It is an object to obtain a high dye laser device and a method of adjusting the optical axis of the dye laser beam.

[0013]

According to a first aspect of the present invention, there is provided a dye laser device comprising: a dye laser multi-stage amplifier in which one dye laser oscillator and at least two dye laser amplifiers are connected in series; An excitation laser device that emits an excitation laser beam to excite an amplifier, an optical fiber that transmits the excitation laser beam emitted by the excitation laser device to the dye laser amplifier, the excitation laser device, A closing unit provided between the dye laser amplifier and blocking the excitation laser beam; and an opening / closing control unit for controlling opening / closing of the closing unit. When adjusting the optical axis of the dye laser beam emitted from the amplifier, the dye laser amplifier prior to the dye laser amplifier that is adjusting the optical axis is It enters the excitation laser beam to open the Saegi閉 means, and thereby controlling to close the Saegi閉 means downstream dye laser amplifier including a dye laser amplifier in the optical axis adjustment.

Further, in the dye laser device according to the second aspect, the blocking means is provided between the excitation laser device and the optical fiber.

Further, in the dye laser device according to the third aspect, the blocking means is provided between the optical fiber and the dye laser amplifier.

The dye laser device according to the present invention further comprises an output detection device for detecting the power of the laser beam emitted from the dye laser oscillator, and the opening / closing control device controls the signal output from the output detection device to a specified value. In the following cases, control is performed so as to close each shielding means.

Further, in the dye laser device according to the fifth aspect, the closing means is capable of moving back and forth with respect to the path of the excitation laser beam, and has a movable portion having a cooling channel, and guides the movement of the movable portion. And a fixing part to be formed.

According to a sixth aspect of the present invention, there is provided a dye laser beam optical axis adjusting method for a dye laser apparatus, wherein the excitation laser beam is emitted only to the dye laser amplifier preceding the dye laser amplifier during the optical axis adjustment. The optical axis of the dye laser beam is adjusted in the excited state.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. In the following description, the same components as those of the above-described conventional example will be denoted by the same reference numerals. Embodiment 1 FIG. FIG. 1 is a schematic diagram of a dye laser device according to Embodiment 1 of the present invention. The dye laser device of this embodiment is also a dye laser device for isotope separation similar to the conventional example. This laser device excites one dye laser oscillator 3, three stages of dye laser amplifiers 4, 5, 6 connected in series to the dye laser oscillator 3 and each dye laser amplifier 4, 5, 6. , And an optical fiber 2 for transmitting an excitation laser beam emitted from each solid-state laser device 1 to a dye laser amplifier 4. In this embodiment, an optical fiber 2 having a core diameter of 0.4 mm to 1.0 mm is used.

The dye laser oscillator 3 has a wavelength selecting element such as an etalon inside, and generates low-power (1 W or less), but high-quality dye laser beams whose wavelength is controlled with high precision. It has become. The dye laser oscillator 3 has a dedicated solid-state laser device 15 built-in, and there is no need to supply an excitation laser beam from the outside through the optical fiber 2. Dye laser amplifiers 4, 5, 6
Requires an excitation laser beam having a higher power in a later stage, so that more optical fibers 2 are connected to the dye laser devices 4, 5, and 6 than in the latter stage. Solid-state laser device 1
Between the optical fiber 2 and the solid-state laser device 1
A lens 11 that converges the excitation laser beam 10 output from the camera is provided. The dye laser oscillator 3 has a dedicated solid-state laser device 15 built therein.

A dye laser oscillator 3, a first-stage dye laser amplifier 4, a second-stage dye laser amplifier 5, and a third-stage dye laser amplifier 6 are connected in series to form a dye laser multi-stage amplifier 100 ( DL-MOPA). In the figure, reference numeral 7a denotes a dye laser beam emitted from the dye laser oscillator 3, and 7b denotes a first-stage dye laser amplifier 4.
Is a dye laser beam amplified by the dye laser amplifier 5 in the second stage, and 7d is a dye laser beam amplified by the dye laser amplifier 6 in the third stage.

In the first embodiment, the solid-state laser device 1
Solid-state laser device 1 provided between the optical fiber 2
Means 14 and a lens 11 for respectively blocking the excitation laser beam emitted from the laser, an opening / closing controller 17 electrically connected to the means 14 for controlling the opening and closing of the means 14, and a dye laser Output detection device 16 for detecting the power of dye laser beam 7a emitted from oscillator 3
And The opening / closing control device 17 is electrically connected to all the shielding means 14, and each of the dye laser amplifiers 4,
At the time of the optical axis adjustment of 5, 6, the shielding means 14 for the dye laser amplifier preceding the dye laser amplifier during the optical axis adjustment is opened, and the subsequent dye laser amplifier including the dye laser amplifier during the optical axis adjustment is opened. It controls so that the closing means 14 may be closed. Further, the opening / closing control device 17 is electrically connected to the output detection device 16.

FIG. 2 is an enlarged view of a main part of the dye laser amplifier 6 at the third stage. The other dye laser amplifiers 4 and 5 have the same structure. In FIG. 2, reference numeral 8 denotes a dye cell, and inside the dye cell 8, a flow path 8 through which a dye solution 9 flows.
The flow path 8a of the dye cell 8, the optical fiber 2, and the dye laser beam 7c are orthogonal to each other.

FIG. 3 is a perspective view of the shielding means 14. The opening / closing means 14 includes a movable part 14a that can move forward and backward with respect to the path of the excitation laser beam 12, and a fixed part 14b that guides the movable part 14a. A cooling water flow path 14c is provided inside the movable part 14a, and a cooling water inlet 14d and a cooling water outlet 14e are provided at an end face of the movable part 14a.

Next, the operation of the dye laser device according to the first embodiment will be described. One solid-state laser device 1
From the excitation laser beam 10 having a power of 30 to 50 W
Is output. The plurality of solid-state laser devices 1 are operated in parallel according to the required power. The excitation laser beam 10 is converged by the lens 11 and introduced into the end face of the optical fiber 2. The excitation laser beam 12 transmitted through the optical fiber 2 enters the dye laser amplifiers 4, 5 and 6.

On the other hand, the dye laser beam 7a emitted from the dye laser oscillator 3 passes through the first-stage dye laser amplifier 4, the second-stage dye laser amplifier 5, and the third-stage dye laser amplifier 6. Amplified sequentially, finally several kW
And is emitted as a high-power dye laser beam 7d.

Although the dye laser beam 7d emitted from the dye laser amplifier 6 is amplified and its power is increased, the quality of the beam such as wavelength and wavefront is reduced by the quality of the incident dye laser beam 7c. I keep it as it is.

Next, a specific example of the optical axis adjustment of the dye beam laser according to the present invention will be described. First, all the shielding means 14 are closed. Then, the excitation laser beam enters only the dye laser oscillator 3 and oscillation occurs, and the dye laser beam 7a is emitted. Using this dye laser beam 7a, the optical axis adjustment of the flow path 8a of the dye cell 8 of the first-stage dye laser amplifier 4 is performed. This optical axis adjustment
An optical system such as a mirror between the dye laser oscillator 3 and the dye laser amplifier 4 is adjusted to visually check whether or not the optical axis is incident on a predetermined portion of the flow path 8a. After this operation is completed, the shielding means 1 for shielding the excitation laser beam incident on the first stage dye laser amplifier 4.
Open only 4. However, at this time, when the output power of the dye laser beam 7a emitted from the dye laser oscillator 3 is zero or does not reach the specified value, the output detection device 16 detects that fact and the opening / closing control device. A control signal for prohibiting opening of all the closing means 14 is sent to 17, so that the closing means 14 does not open. As a result, the occurrence of ASE and backflow caused by the output power of the dye laser beam 7a emitted from the dye laser oscillator 3 being zero or less than a specified value due to an erroneous operation (opening / closing) of the dye laser oscillator 3 or the like. Can be prevented.

Next, the optical axis of the flow path 8a of the dye cell 8 of the second-stage dye laser amplifier 5 is adjusted using the dye laser beam 7b emitted from the first-stage dye laser amplifier 4. . This adjustment operation is the same as the optical axis adjustment operation of the first-stage dye laser amplifier 4 described above. After this operation is completed, the shielding means 14 for shielding the excitation laser beam to the second-stage dye laser amplifier 5 is opened.
However, when the optical axis of the flow path 8a of the dye cell 8 of the second-stage dye laser amplifier 5 is adjusted, the excitation laser beam blocking means 14 for the first-stage dye laser amplifier 4 is closed.
Is closed, the opening and closing control device 1 is not opened.
7 is set.

Next, the optical axis of the flow path 8a of the dye cell 8 of the third dye laser amplifier 6 is adjusted using the dye laser beam 7c emitted from the second dye laser amplifier 5. I do. After this operation is completed, the shielding means 14 for shielding the excitation laser beam to the third-stage dye laser amplifier 6 is opened. However, the first stage and the second stage
An opening / closing control device 17 is set so as not to open when the closing means 14 of the dye laser amplifiers 4 and 5 of the stage is closed.

The width and position of the dye laser beam 7 in each of the dye laser amplifiers 4, 5, and 6 are precisely adjusted to the flow path 8 a of the dye cell 8 by the above-described series of operations for adjusting the optical axis of the dye laser beam. Can be matched.

FIG. 4 shows an example of a setting sequence of the opening / closing control device 17 described above. The sequence in FIG. 4 is a control example of the shielding means 14 of the dye laser amplifier 6 at the third stage.
In FIG. 4, the dye laser amplifier is abbreviated as an amplifier. First, an instruction to open the shielding means 14 of the third stage dye laser amplifier 6 is input (step S1). This instruction is input, for example, by pressing an “open” button of the closing means 14. In response to this input, the process proceeds to step S2, in which the closing means 14 for the second stage dye laser amplifier 5
It is determined whether or not is open, and if it is not open, the process proceeds to step 3 to display "prohibition of opening" of the shielding means 14 to the dye laser amplifier 6 at the third stage.

If the closing means 14 of the second stage dye laser amplifier 5 is open, the process proceeds to the next step S4.
It is determined whether or not the closing means 14 of the first-stage dye laser amplifier 4 is open. If the closing means 14 is not open, the process proceeds to step S5, and the action of the third-stage dye laser amplifier 6 is performed. "Opening prohibition" of the shielding means 14 is displayed. If the closing means 14 of the first-stage dye laser amplifier 5 is open, the process proceeds to the next step S6, where the output detecting device 1
It is determined whether the signal No. 6 is equal to or greater than the specified value. If the signal is not equal to or greater than the specified value, the flow advances to step S7 to display "open prohibition" of the corresponding closing means 14 of the third-stage dye laser amplifier 6. If it is determined that the signal from the output detector 16 is equal to or greater than the specified value, the process proceeds to step S8, where the third stage dye laser amplifier 4
Is opened.

As described above, according to this embodiment,
Since the optical axis can be adjusted using a dye laser beam actually incident on the dye laser amplifier instead of the pilot beam, the flow path 8a of the dye cell 8 can be adjusted.
This makes it possible to perform precise adjustment up to the vicinity of the wall, and as a result, a dye laser device with high output efficiency can be obtained. Further, in opening and closing the shielding means 14, it is possible to prevent the dye laser device from being damaged due to a human erroneous operation.

Embodiment 2 Next, a second embodiment of the present invention will be described. In the following description, only points different from the first embodiment will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted. FIG. 5 is a schematic diagram of a laser device for isotope separation according to Embodiment 2 of the present invention. In the second embodiment, the excitation laser beam 12 emitted from the plurality of optical fibers 2 is converged between the optical fiber 2 and each of the dye laser amplifiers 4, 5, and 6, and the dye laser amplifiers 4, 5, and 6 are condensed.
There is provided a lens 11 for causing the laser beam to enter the laser beam and a closing means 14 for blocking the excitation laser beam 12. Each of the blocking means 14 is connected to an opening / closing control device 17 which, when adjusting the optical axis of each dye laser beam, shuts off the dye laser amplifier at a stage preceding the dye laser amplifier whose optical axis is being adjusted. Each of the closing means 14 is controlled so as to open the means 14 and close the closing means 14 for the subsequent dye laser amplifier including the dye laser amplifier whose optical axis is being adjusted.

FIG. 6 is an enlarged view of a main part of the dye laser amplifier 6. The other dye laser amplifiers 4 and 5 have the same structure. In the figure, a flow channel 8 is provided inside a dye cell 8.
a is provided, and the dye solution 9 flows through the flow channel 8a. The flow path 8a, the excitation laser beam 12, and the dye laser beam 7c of the dye cell 8 are orthogonal to each other.

Next, the operation of the dye laser device according to the second embodiment will be described. The excitation laser beam 10 is
The light is converged by the lens 11, introduced into the optical fiber 2, and transmitted. The excitation laser beam 12 emitted from the optical fiber 2 propagates while diverging in space, and
3 is incident. The plurality of excitation laser beams 12 are converged by the lens 13 and are dye laser amplifiers 4, 5,.
6 is incident.

On the other hand, the dye laser beam 7a emitted from the dye laser oscillator 3 passes through the first-stage dye laser amplifier 4, the second-stage dye laser amplifier 5, and the third-stage dye laser amplifier 6. The dye laser beam is sequentially amplified and finally emitted as a high power dye laser beam 7d of several kW.

In the dye laser device according to the second embodiment,
Since the shielding means 14 is arranged between the dye laser amplifiers 4, 5, and 6 and the plurality of optical fibers 2, the number of the shielding means is smaller than that of the first embodiment, so that the cost can be reduced. Can be.

[0040]

As described above, in the dye laser device according to the first aspect of the present invention, a dye laser multistage amplifying device in which one dye laser oscillator and at least two dye laser amplifiers are connected in series is provided. An excitation laser device that emits an excitation laser beam to excite a dye laser amplifier, an optical fiber that transmits the excitation laser beam emitted by the excitation laser device to the dye laser amplifier, and an excitation laser device And a closing means for blocking the excitation laser beam, respectively, provided between the dye laser amplifier, and an opening and closing control device for controlling opening and closing of the closing means. When adjusting the optical axis of the dye laser beam emitted from the dye laser amplifier, the dye laser amplifier is positioned at a stage prior to the dye laser amplifier whose optical axis is being adjusted. In this case, the closing means is opened to receive the excitation laser beam, and the closing means of the subsequent dye laser amplifier including the dye laser amplifier whose optical axis is being adjusted is controlled to be closed. Therefore, it is possible to perform the optical axis adjustment using a dye laser beam actually incident on the dye laser amplifier instead of the pilot beam as in the related art.For example, the width and position of the dye laser beam can be adjusted for each dye. It becomes possible to precisely match the vicinity of the wall of the flow path of the dye cell of the laser amplifier, and as a result, the output efficiency is improved.

Further, in the dye laser device according to the second aspect, since the shielding means is provided between the excitation laser device and the optical fiber, the excitation laser emitted from the excitation laser device by the shielding means. Is securely closed.

Further, in the dye laser device according to the third aspect, since the blocking means is provided between the optical fiber and the dye laser amplifier, the light is emitted from the plurality of optical fibers toward one dye laser amplifier. It is sufficient to provide one closing means for the excitation laser, and the number of the closing means can be reduced to the minimum necessary, so that the cost is reduced.

Further, the dye laser device according to claim 4 is provided with an output detection device for detecting the power of the laser beam emitted from the dye laser oscillator, and the opening / closing control device is configured to control the signal output from the output detection device to a specified value. In the following cases, the closing means is controlled so as to close, so that unnecessary light and backflow caused by the output power of the dye laser beam being zero or less than a specified value can be prevented.

Further, in the dye laser device according to the fifth aspect, the blocking means is capable of moving back and forth with respect to the path of the excitation laser beam and guides the movable portion having the cooling flow path and the movement of the movable portion. The excitation laser can be shielded with a simple configuration.

Further, according to the method for adjusting the optical axis of a dye laser beam of a dye laser device according to the sixth aspect, the excitation laser beam is emitted only to the dye laser amplifier preceding the dye laser amplifier whose optical axis is being adjusted. Since the optical axis of the dye laser beam is adjusted in the excited state, the optical axis can be adjusted using the dye laser beam actually incident on the dye laser amplifier instead of the pilot beam as in the conventional case. Yes, output efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a dye laser device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the dye laser amplifier according to the first embodiment of the present invention.

FIG. 3 is a perspective view of the shielding means of FIG. 1;

FIG. 4 is a diagram showing an example of a sequence of the opening / closing control device of FIG. 1;

FIG. 5 is a configuration diagram illustrating a dye laser device according to a second embodiment of the present invention.

FIG. 6 is an enlarged view of a main part of the dye laser amplifier of FIG. 5;

FIG. 7 is a configuration diagram showing a conventional dye laser device.

FIG. 8 is an enlarged view of a main part of the dye laser amplifier of FIG. 7;

FIG. 9 is a diagram showing a cross-sectional power distribution of a dye laser beam.

FIG. 10 is a diagram showing a cross-sectional power distribution of a dye laser beam in the case of poor adjustment.

FIG. 11 is a diagram showing a cross-sectional power distribution of a pilot beam.

[Explanation of symbols]

1 solid-state laser device, 2 optical fiber, 3 dye laser oscillator, 1st dye laser amplifier, 5 second
6th stage dye laser amplifier, 3rd stage dye laser amplifier, 14 shielding means, 16 output detection device, 17 opening / closing control device.

Claims (6)

[Claims] 1. One dye laser oscillator and at least two
A dye laser multi-stage amplifier in which two dye laser amplifiers are connected in series; an excitation laser device that emits an excitation laser beam to excite the dye laser amplifiers; and an excitation laser that is emitted by the excitation laser device. An optical fiber for transmitting a laser beam to the dye laser amplifier; closing means provided between the excitation laser device and the dye laser amplifier to shut off the excitation laser beam; An opening / closing control device for controlling the operation of the dye laser amplifier, when the optical axis of the dye laser beam emitted from each of the dye laser amplifiers is adjusted, On the other hand, the shielding means is opened to receive the excitation laser beam, and the subsequent dye laser including the dye laser amplifier whose optical axis is being adjusted. Dye laser apparatus for controlling to close the Saegi閉 means of the amplifier. 2. The dye laser device according to claim 1, wherein the shielding means is provided between the excitation laser device and the optical fiber. 3. The dye laser device according to claim 1, wherein the shielding means is provided between the optical fiber and the dye laser amplifier. 4. An output detection device for detecting the power of a laser beam emitted from a dye laser oscillator, wherein the opening / closing control device closes each blocking means when a signal output from the output detection device is equal to or less than a specified value. The dye laser device according to any one of claims 1 to 3, wherein the dye laser device is controlled to: 5. A movable unit that can move forward and backward with respect to the path of the excitation laser beam and has a cooling channel,
2. A fixed part for guiding the movement of the movable part.
A dye laser device according to claim 4. 6. One dye laser oscillator and at least two
A dye laser multi-stage amplifying device in which two dye laser amplifiers are connected in series, an excitation laser device for emitting an excitation laser beam for exciting each of the dye laser amplifiers for emitting a dye laser beam, and an excitation laser device An optical fiber for transmitting the excitation laser beam emitted in the step (a) to the dye laser amplifier, wherein the optical axis of the dye laser beam is adjusted in a stage prior to the dye laser amplifier during the optical axis adjustment. And adjusting the optical axis of the dye laser beam in a state where the excitation laser beam is emitted and excited only to the dye laser amplifier.