JP2000174373A - Liquid laser apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid laser apparatus, wherein when exciting light is transmitted through a plurality of optical fibers, the irradiated positions in a coloring matter solution resulting from the exciting light beams emitted from respective fibers coincide with each other, and laser oscillation or an amplification characteristic due to excitation from any fiber will be equal to each other by making flat the intensity distribution of the exciting light in the laser medium. SOLUTION: In a liquid laser apparatus, wherein a cell 1 having a slit 3 for enclosing or circulating a laser medium is irradiated with exciting light in a predetermined direction to excite the laser medium so that an excitation region 4 is formed in the slit 3, and at the same time, laser oscillation or amplification is carried out by using the excitation region 4 as a gain medium, the laser apparatus is provided with a waveguide 7 for guiding the exciting light to the laser medium and the emitting surface of the waveguide 7 is made contiguous with the laser medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid laser device which is excited by excitation light and oscillates or amplifies laser light.

[0002]

2. Description of the Related Art FIG. 43 is a block diagram of a dye laser device described as an example of a conventional liquid laser device and described in, for example, Japanese Patent Application Laid-Open No. 62-141793. In the figure, 1 is a dye cell, 2 is a dye solution, 6 is an optical fiber, 21 is a prismatic lens, 22 is a mount, P is excitation light, and D is dye laser light.

[0003] Next, the operation of the conventional apparatus will be described. In this dye laser device, the excitation light P is guided to the vicinity of the dye cell 1 by the optical fiber 6. A part of the side wall of the dye cell 1 is a prismatic lens 21 having a one-way refractive index distribution, and a part of the side of the glass container is cut off and fused to the part. As shown in FIG. 44, only the Z direction, which is the thickness direction, has a parabolic refractive index distribution 23 around an axis, as shown in FIG.
And light travels straight in the width direction (X) and the longitudinal direction (Y). The refractive index distribution 23
Is gradually determined according to the formula of n (Z) 2 = n0 (1−g2Z2) (where n0 is an axial refractive index, n (Z) is a refractive index along the thickness, and g is a constant representing a refractive index gradient). To decrease. The arrangement of the optical fiber 6 and the dye cell 1 is shown in FIG.
As described in detail in FIG. 5, a mount 22 is provided on one end of which the dye cell 1 faces the prismatic lens 21 toward the other end and the width direction (X) of the prismatic lens 21 is the mounting surface of the mount 22. It is fixed parallel to. With the above configuration, the excitation light P guided by the optical fiber 6 is incident on the prismatic lens 21. The incident excitation light P converges only in the thickness direction, that is, the Z direction, as shown by the broken lines in FIGS. 43 and 45, and is collected in the dye solution 2 enclosed or circulated in the dye cell 1 in a slit shape. Light. Here, the luminous flux of the excitation light P emitted from the prismatic lens 21 can be aligned with the optical axis of the dye laser light D by appropriately determining the length in the longitudinal direction (Y) at the portion of the prismatic lens 21. .

[0004]

The conventional dye laser device shown in FIG. 43 is configured as described above, and the excitation light is not controlled in the width direction (X) of the prismatic lens.
There is a problem that the intensity distribution of the excitation light in the dye solution becomes non-uniform. Further, when the excitation light is transmitted through a plurality of optical fibers, part of the excitation light incident on the prismatic lens leaks from the width direction (X) of the prismatic lens or is emitted from each fiber. There is a problem that the irradiation position of the excitation light in the dye solution is different, and the oscillation or amplification characteristics of the dye laser are different for each excitation from each fiber.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it has been proposed that the intensity distribution of the excitation light in the dye solution be flattened and that the excitation light be transmitted through a plurality of optical fibers. It is an object of the present invention to provide a dye laser device in which the irradiation positions of the excitation light emitted from the fibers are matched with the dye solution so that the oscillation or amplification characteristics of the dye laser are equalized even when excitation is performed from any fiber.

[0006]

According to the first aspect of the present invention, a cell having a slit for enclosing or circulating a laser medium is irradiated with excitation light from a predetermined direction to excite the laser medium, thereby exciting the laser medium. In a liquid laser device that forms a region and performs laser oscillation or amplification using the excitation region as a gain medium, the liquid laser device includes a waveguide for guiding the excitation light to the laser medium, and an emission surface of the waveguide is formed on the laser medium. It is characterized in that it is configured to contact.

According to a second aspect of the present invention, in the liquid laser device according to the first aspect, the waveguide has a single focusing means for guiding the excitation light to the laser medium and a direction perpendicular to the focusing direction. A waveguide structure.

According to a third aspect of the present invention, in the liquid laser device of the first aspect, a waveguide is provided in a shape that contracts in a direction in which the excitation light travels.

The invention according to claim 4 is the invention according to claims 1 to 3.
The liquid laser device according to any one of the above, wherein the main body of the cell is metal, a transparent window for the laser light is provided on the optical path of the laser light, and the waveguide is bonded to the main body of the cell. .

[0010] The invention of claim 5 is the invention of claims 1 to 3.
In the liquid laser device according to any one of the above, the main body of the cell is metal, a window transparent to the laser light is provided on the optical path of the laser light, and the waveguide is provided with packing between the main body of the cell and the waveguide. It is characterized by the following.

[0011] The invention of claim 6 is the first to third aspects of the present invention.
Wherein the main body of the cell is made of a material that is transparent to laser light, and is provided with a waveguide having a refractive index larger than that of the main body of the cell.

The invention of claim 7 is the first to sixth aspects of the present invention.
The liquid laser device according to any one of the above, wherein the waveguide is surrounded by a protective plate made of a material having a lower refractive index than the waveguide.

The invention of claim 8 is the first to seventh aspects of the present invention.
Wherein the protective plate is shorter than the waveguide, and the protective plate is configured to serve as a means for fixing the waveguide and controlling the position of the waveguide.

[0014] The invention of claim 9 is the invention of claims 1 to 8
In the liquid laser device according to any one of the above, a flange is provided on the protective plate to use the protective plate as a means for fixing the waveguide and controlling the position of the waveguide.

According to a tenth aspect of the present invention, in the liquid laser device according to any one of the first to ninth aspects, a part of the excitation light is reflected at least once or more on the surface in the longitudinal direction of the cross section of the waveguide. It is characterized by having comprised.

According to an eleventh aspect of the present invention, in the liquid laser device according to any one of the first to eleventh aspects, light from a plurality of light sources having different pulse phases is guided to the waveguide as excitation light. And a configuration for synthesizing the excitation light.

According to a twelfth aspect of the present invention, in the liquid laser device according to the first or second aspect, the light condensing means and the waveguide are arranged independently.

According to a thirteenth aspect of the present invention, in the liquid laser device according to the first or the second aspect, the second condensing means is integrated with the independent first condensing means and the waveguide. It is a combination optical system of the means.

According to a fourteenth aspect of the present invention, in the liquid laser device according to the first or second aspect, the condensing means is a hologram formed on the excitation light incident surface of the waveguide.

According to a fifteenth aspect of the present invention, in the liquid laser device according to any one of the first to sixth and twelfth to fourteenth aspects, an optical fiber for guiding excitation light is provided,
It is characterized in that the image of the exit surface of the optical fiber is formed on the laser medium by the focusing means.

According to a sixteenth aspect of the present invention, in the liquid laser device according to any one of the first to sixth and twelfth to fourteenth aspects, a beam homogenizer for uniformizing the intensity distribution of the excitation light is provided. And a condensing means for forming an image of an exit surface of the beam homogenizer on a laser medium.

According to a seventeenth aspect of the present invention, in the liquid laser device according to any one of the first to sixth and twelfth to fourteenth aspects, the waveguide has a beam width of the excitation light on the plane of incidence of the excitation light. The width of the waveguide in the focusing direction is substantially equal to the beam width of the laser beam at a position where the laser beam is focused by the focusing means in the waveguide, which is larger than the beam width of the laser beam. I do.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. Embodiment 1
1 shows an embodiment of a liquid laser device according to claim 1 and claim 2, wherein excitation light is irradiated from a predetermined direction to a cell having a slit for enclosing or circulating a laser medium, as shown in FIGS. An excitation region is formed in the slit by exciting the laser medium, and a liquid laser device that performs laser oscillation or amplification using the excitation region as a gain medium includes a waveguide for guiding the excitation light to the laser medium. And an emission surface of the waveguide is configured to be in contact with the laser medium. Also, FIG.
As shown in FIG. 4, the waveguide in the liquid laser device may be configured to have a single desired means for guiding the excitation light to the laser medium and a waveguide structure in a direction perpendicular to the desired direction. it can.

Hereinafter, a specific description will be given based on the drawings. FIG. 1 is a plan view showing a configuration of a dye laser device as a liquid laser device, and FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG.
FIG. 4 is a plan view showing a configuration of another dye laser device having one optical fiber, and FIG. 4 is a cross-sectional view taken along line AA of FIG. 1 to 4, reference numeral 1 denotes a dye cell, 2 denotes a dye solution, 3 denotes a slit, 4 denotes an excitation region, 5 denotes a dye laser window, 6 denotes an optical fiber, 7 denotes a waveguide, D denotes a dye laser beam, P is an excitation laser beam.

In FIG. 1 and FIG. 2, a dye solution 2 serving as a laser medium is supplied to a slit 3 of a sealed dye cell 1.
Circulating inside. For example, the second harmonic of a solid-state laser,
When excitation light P such as a copper vapor laser or an excimer laser is applied to the dye solution 2 in the dye cell 1, the dye molecules in the dye solution 2 absorb light and are excited by the excitation light P, and the An excitation region 4 is formed along the inside.
On the other hand, the dye laser light D passes through the dye laser window 5, enters the dye solution 2, and gains and is amplified by passing through the excitation region 7. Here, the excitation light P is transmitted to the dye cell 1 by, for example, the optical fiber 6 and the waveguide 7
And is reflected many times on the wall surface of the waveguide 7 to irradiate the dye solution 2 in a state where the intensity distribution is flat. still,
The shape of the exit surface of the waveguide 7 is matched with the shape of the dye laser beam D passing through the dye solution 2 to form the excitation region 4.

The waveguide 7 in FIG. 3 and FIG.
The incident surface is processed into a cylindrical lens shape as a condensing means, and the excitation light P is converged in a direction perpendicular to the traveling direction of the dye laser light D, and is irradiated on the dye solution 2. On the other hand, the excitation light P
Is reflected many times on the wall surface of the waveguide in a direction parallel to the traveling direction of the dye laser light D, and enters the dye solution 1 in a state where the intensity distribution is flat. Therefore, the excitation region 4
The dye laser beam D is formed according to the shape of the dye solution 2 passing through the dye solution 2.

Referring again to FIGS. 1 and 2, the excitation area 4 is excited by the excitation light P having a flat intensity distribution in the direction parallel to the traveling direction of the dye laser light D so that the dye laser light D Since it is formed according to the shape passing through the inside, the beam intensity distribution after oscillation or amplification of the dye laser beam D can be flattened. Further, even if the pumping light P is moved within the plane of incidence of the waveguide, for example, in the direction parallel to the traveling direction of the dye laser light D, the laser oscillation or amplification characteristics can be equalized. Further, even in the case of transmission through a plurality of optical fibers, the irradiation position of the excitation light emitted from each fiber in the laser medium can be matched, and the oscillation or amplification characteristics of the laser can be made equal regardless of the excitation from any fiber. Can be.

In this embodiment, the configuration in which the dye cell 1 is irradiated with the excitation light P from both sides has been described. However, the same effect can be obtained by irradiating the excitation light P from one side. Further, by applying a non-reflection coating to the surface of the dye laser window 5 and the waveguide 7 on the atmosphere side, the oscillation or amplification efficiency of the dye laser light D can be improved. When the surface of the dye laser window 5 on the air side is configured to allow the dye laser light D to enter at a Brewster angle, the polarization direction of the dye laser light D can be controlled and the transmission loss can be minimized.
In addition, by making the dye-side surfaces of the dye laser windows 5 facing each other non-parallel, irregular oscillation can be suppressed. Note that the cylindrical lens-shaped processing of the incident surface of the excitation light P of the waveguide 7 shown in FIGS. 3 and 4 may have any shape as long as the excitation light P is condensed in the dye solution 2.

Embodiment 2 FIG. 5 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 2 of the present invention, and FIG. 6 is a sectional view taken along line AA of FIG.
FIG. 7 is a plan view showing a configuration of a dye laser device in which the waveguide 7 is shorter than that of FIG. 5, and FIG. 8 is a sectional view taken along line AA of FIG. In the first embodiment, the waveguide 7 is shown as a rectangular parallelepiped. However, in the second embodiment, the width direction of the waveguide 7 (the direction parallel to the traveling direction of the dye laser beam D) is set to the traveling direction of the excitation light P. And contracted. Therefore, in addition to obtaining the same effects as in the first embodiment, the laser medium can be efficiently irradiated with the excitation light having a large beam width. Further, when the excitation light P is incident on the waveguide 7 by the optical fiber 6, more optical fibers can be used.

FIG. 9 is a plan view showing a configuration of a dye laser device as another liquid laser device according to Embodiment 2 of the present invention. FIG. 10 is a sectional view taken along the line AA. In this embodiment, in the thickness direction of the waveguide 7 (dye laser light D
(Perpendicular to the direction of travel) was made to contract in the direction of travel of the excitation light P. Therefore, in addition to obtaining the same effects as in the first embodiment, the laser medium can be efficiently irradiated with the excitation light having a large beam width. Further, when the excitation light P is incident on the waveguide 7 by the optical fiber 6, more optical fibers can be used. 7 to 10 show a configuration in which the waveguide 7 contracts in one direction of the width direction or the thickness direction, but a configuration in which the waveguide 7 contracts in two directions of the width direction and the thickness direction. If so, more optical fibers can be used.

Embodiment 3 FIG. 11 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 3 of the present invention, and FIG. 12 is a cross-sectional view taken along line AA of FIG. FIG. 13 is a plan view showing a configuration of a dye laser device having one optical fiber, and FIG.
It is A sectional drawing. FIGS. 11 and 12 show examples of a configuration having three optical fibers. In the figure, reference numeral 8 denotes an adhesive.
In the third embodiment, the main body of the dye cell 1 is made of metal, a dye laser window 5 transparent to laser light is provided on the optical path of the dye laser light D, and the waveguide 7 is attached to the main body of the dye cell 1. It is bonded. By using an adhesive 8 having a refractive index lower than that of the waveguide 7, the excitation light P can be totally reflected on the inner surface of the waveguide 7. Because it was configured by bonding,
Handling becomes easy.

Embodiment 4 FIG. FIG. 15 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 4 of the present invention, and FIG. 16 is a sectional view taken along line AA of FIG. FIG. 17 is a plan view showing a configuration of a dye laser device having one optical fiber, and FIG.
It is A sectional drawing. FIGS. 17 and 18 show an example of a configuration having one optical fiber. In the figure, reference numeral 9 denotes packing. In the fourth embodiment, the main body of the dye cell 1 is made of metal, and a dye laser window 5 transparent to the laser light is provided on the optical path of the dye laser light D. A packing 9 such as an O-ring is provided. Since the structure is decomposable, replacement of the waveguide 7 is facilitated.

Embodiment 5 FIG. FIG. 19 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 5 of the present invention, and FIG. 20 is a sectional view taken along line AA of FIG. FIG. 21 is a plan view showing the structure of a dye laser device having one optical fiber, and FIG.
It is A sectional drawing. In the fifth embodiment, the main body of the dye cell 1 is made of a material that is transparent to the laser light, and includes the waveguide 7 having a refractive index larger than the refractive index of the main body of the dye cell 1. In addition to the fact that the excitation light P can be totally reflected inside the waveguide 7, the dye cell body 1 is transparent, so that the dye solution 2 can be observed.

Embodiment 6 FIG. FIG. 23 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 6 of the present invention, and FIG. 24 is a sectional view taken along the line AA of FIG. In the figure, reference numeral 10 denotes a protection plate. In the first to fifth embodiments, the waveguide 7 is directly installed in the dye cell 1 main body. In the sixth embodiment, however, the waveguide 7 is installed.
Is surrounded by a protective plate 10. If the output path is chamfered to prevent damage during assembly, the optical path of the excitation light P on the output surface is partially shielded, so that the transmittance of the excitation light P is reduced. However, by adopting a configuration in which the waveguide 7 is surrounded by the protective plate 10, chamfering of the emission surface of the waveguide 7 becomes unnecessary, and further, a decrease in the transmittance of the excitation light P can be prevented. Further, when the thickness of the waveguide 7 is small, it is possible to prevent the waveguide 7 from being damaged even during handling before assembly. The bonding between the waveguide 7 and the protection plate 10 is performed by using an adhesive having a lower refractive index than that of the waveguide 7 or by bringing the protection plate 10 having a lower refractive index than the waveguide 7 into close contact with the waveguide 7.

In the sixth embodiment, the configuration in which the periphery of the waveguide 7 is surrounded by the protective plate 10 is shown. However, the configuration in which the waveguide 7 is sandwiched by the protective plate 10 in the thickness direction may be employed. Since the chamfering of the emission surface in the vertical direction can be omitted, a decrease in the transmittance of the excitation light P can be prevented.

Embodiment 7 FIG. 25 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 7 of the present invention, and FIG. 26 is a sectional view taken along line AA of FIG. In the figure, reference numeral 11 denotes a waveguide support block that supports the waveguide 7. In the sixth embodiment, the entire waveguide 7 is surrounded by the protective plate 10.
In this configuration, the protection plate 10 is shorter than the entire length of the waveguide 7, and the protection plate 10 is used as a means for fixing and positioning the waveguide 7. By providing the protection plate 10 on the exit surface of the waveguide 7 for the excitation light P, the same effect as in the sixth embodiment can be obtained, and the waveguide 7 is formed using the step between the waveguide 7 and the protection plate 10. Since it can be fixed to the dye cell 1, the installation position accuracy of the waveguide 7 can be improved.

Embodiment 8 FIG. FIG. 27 is a plan view showing the configuration of a dye laser device as a liquid laser device according to Embodiment 8 of the present invention, and FIG. 28 is a sectional view taken along line AA of FIG. In the seventh embodiment, the configuration in which the protection plate 10 is shorter than the entire length of the waveguide 7 and the protection plate 10 is used as the fixing and position control means of the waveguide 7 has been described.
In the above, the protection plate 10 is provided with the flange 11 to fix the waveguide 7 and control the position. By providing the protection plate 10 on the emission surface of the excitation light P of the waveguide 7, the same effect as in the sixth embodiment can be obtained, and by providing the protection plate 10 with the flange 11, the fixing of the waveguide 7 and In addition to more reliable position control, the flange 11 of the protection plate 10 can be used for sealing the dye solution 1.

Embodiment 9 FIG. 29 is a partially enlarged plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 9 of the present invention, and FIG. 30 is an example of a waveguide 7 having a short length. In the first to eighth embodiments, the width and the length of the waveguide 7 are not described. However, in the ninth embodiment, the maximum incident angle θ0 of the pump light P to the waveguide 7 and the width of the waveguide 7 w, the length L of the waveguide is expressed as follows: L ≧ (wd) / tan ｛sin−1 (n0 / n1 · s
inθ0)｝. Here, n0 is the refractive index of air, n1
Is the refractive index of the waveguide, and d is the core diameter of the optical fiber. In such a configuration, the excitation light P is reflected by the waveguide 7 at least once, so that the intensity distribution of the excitation light P in the laser medium 2 can be reliably flattened. Therefore, in this configuration, the conversion efficiency from the excitation light P to the dye laser light D can be improved.

Embodiment 10 FIG. FIG. 31 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 10 of the present invention, and FIG. 32 is an example of a waveguide 7 having a short length. In the figure, reference numeral 12 denotes a second harmonic generator of, for example, an LD-pumped solid-state laser as a pump laser. Next, the operation will be described. It is assumed that the pulse repetition frequency of the pump laser 12 is fp and, for example, three sets of pump lasers 12 perform pulse oscillation operations with different phases. The pump laser 12 light oscillated at each phase is transmitted by, for example, the optical fiber 6 and is incident on the waveguide 7 as described in the first to ninth embodiments. Here, an optical fiber 6 that emits pump light P of different phase
Is arranged, the intensity distribution of the excitation light P passing through the waveguide 7 in the dye solution 2 becomes substantially the same. Therefore, the same excitation region 4 is formed in each phase, and the dye laser light D has a frequency three times the pulse repetition frequency of the excitation laser P; fd
= 3 fp repetition frequency. Here, the case where three sets of the pumping lasers 12 are used has been described, but the present invention can be generally applied to the oscillation or amplification of the dye laser light D that is higher than the repetition frequency of the pumping light P.

Embodiment 11 FIG. FIG. 33 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 11 of the present invention, and FIG. 34 is a sectional view taken along line AA of FIG. In the figure, reference numeral 13 denotes a lens as a light collecting means. In FIGS. 3 and 4 of the first embodiment, as is clear from FIG. 4, the cylindrical lens as the light condensing means and the waveguide 7 are shown as an integral structure. However, in the eleventh embodiment,
The lens 13 as the light condensing means and the waveguide 7 were configured independently of each other.

Next, the operation will be described. The excitation light P is
For example, transmitted to the dye cell 1 by an optical fiber,
The light is incident on a lens 13 as a light collecting means. Lens 13
Is a unidirectional lens, and the excitation light P is a dye laser light D
Are converged in a direction perpendicular to the traveling direction of the dye solution, and the dye solution 2 is irradiated through the waveguide 7. In the waveguide 7, the excitation light P is reflected many times on the wall surface of the waveguide in a direction parallel to the traveling direction of the dye laser light D, and is incident on the dye solution 1 in a state where the intensity distribution is flat. Therefore, the excitation region 4 is formed according to the shape of the dye laser beam D passing through the dye solution 2.

As described above, in the eleventh embodiment, the same effects as those of the first embodiment shown in FIGS. 3 and 4 can be obtained, and the excitation light P in the dye solution 2 can be obtained. Adjustment of the intensity distribution is facilitated. In addition, by applying an anti-reflection coating to the entrance surface of the lens 13 and the waveguide 7, the oscillation or amplification efficiency of the dye laser light D can be improved.
The shape of the lens 13 may be any shape as long as the excitation light P is focused on the dye solution 2.

Embodiment 12 FIG. FIG. 35 is a plan view showing a configuration of a dye laser device as a liquid laser device according to a twelfth embodiment of the present invention, and FIG. 36 is a sectional view taken along line AA of FIG. In the first and eleventh embodiments, a single cylindrical lens as a light condensing means is shown as a single lens.
In No. 2, the lens 13 as the first light condensing means and the second light condensing means integrated with the waveguide 7 were combined.

Next, the operation will be described. The excitation light P is
For example, the light is transmitted to the dye cell 1 by the optical fiber 6, and is incident on the lens 13 as the first light collecting means.
The lens 13 is a unidirectional lens, and the excitation light P is converted into the dye laser light D by a combination with a cylindrical lens formed on the excitation light incident surface of the waveguide 7 as the second condensing means.
Is converged in a direction perpendicular to the traveling direction of the dye solution, and the dye solution 2 is irradiated through the waveguide 7. The excitation light P is reflected many times on the wall surface of the waveguide 7 in a direction parallel to the traveling direction of the dye laser light D, and is incident on the dye solution 1 in a state where the intensity distribution is flat. Therefore, the excitation region 4 is formed according to the shape of the dye laser beam D passing through the dye solution 2.

As described above, in the twelfth embodiment, the same effects as those in the first and eleventh embodiments can be obtained, and in addition, when the excitation light P is condensed by the combination of the two condensing optical systems. Can be reduced. In addition, by applying an anti-reflection coating to the entrance surface of the lens 13 and the waveguide 7, the oscillation or amplification efficiency of the dye laser light D can be improved.

Embodiment 13 FIG. FIG. 37 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 13 of the present invention, and FIG. 38 is a sectional view taken along line AA of FIG. In the figure, 14 is a hologram. In Embodiments 1, 11, and 12, the configuration using the cylindrical lens as the light condensing unit is used. However, in Embodiment 13,
The hologram 14 was configured to be integrated with the waveguide 7.

Next, the operation will be described. The excitation light P is
For example, the light is transmitted to the dye cell 1 by the optical fiber 6 and is incident on the waveguide 7. A hologram 14 is formed on the excitation light incident surface of the waveguide 7 so that the excitation light P converges in a direction perpendicular to the direction in which the dye laser light D travels.
Irradiation. The excitation light P is reflected many times on the wall surface of the waveguide 7 in a direction parallel to the traveling direction of the dye laser light D, and is incident on the dye solution 1 in a state where the intensity distribution is flat.
Therefore, the excitation region 4 is formed according to the shape of the dye laser beam D passing through the dye solution 2.

As described above, in the thirteenth embodiment, in addition to obtaining the same effects as those of the first, eleventh, and twelfth embodiments, the hologram 14 allows the excitation light P to be arbitrarily set in the dye solution 2. Since the excitation light P can be converged to the intensity distribution and the excitation light P can be diverged in the traveling direction of the dye laser light D, the excitation light intensity distribution in the dye solution 2 can be made more uniform. By applying a non-reflection coating to the incident surface of the waveguide 7, the oscillation or amplification efficiency of the dye laser light D can be improved.

Embodiment 14 FIG. FIG. 39 is a partially enlarged plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 14 of the present invention. In the above embodiment, the interval and length between the exit surface of the optical fiber 6 and the waveguide 7 are not mentioned, but in the fourteenth embodiment, the exit surface of the optical fiber 6 and the cylindrical lens processed into the waveguide 7 are used. The distance S0 to the first principal point and the second of the cylindrical lens
Configuration in which the relationship between the distance S2 between the principal point and the center of the excitation region and the focal length f of the cylindrical lens light satisfies the following: S0 = n0 / (kS2-n1) S2 = n1 / (kS0-n0) k = n0 / f To Here, n0 is the refractive index of air, and n1 is the refractive index of the waveguide. In such a configuration, since the image of the exit surface of the optical fiber 6 is formed in the dye solution 2, the intensity distribution of the excitation light P in the dye solution 2 matches the beam width of the dye laser light D. be able to. Therefore, in such a configuration, the conversion efficiency from the excitation light P to the dye laser light D can be improved.

Embodiment 15 FIG. FIG. 40 is a partially enlarged plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 15 of the present invention. In the figure,
Reference numeral 15 denotes, for example, a rectangular waveguide as a beam homogenizer. Next, the operation will be described. The excitation laser light P is
For example, after being emitted from the optical fiber 6, the rectangular waveguide 1
5 is incident. After the excitation light P is reflected many times in two directions by the rectangular waveguide 15, the intensity distribution is made uniform and emitted. The distance S1 between the exit surface of the rectangular waveguide 15 and the first principal point of the cylindrical lens processed into the waveguide 7, the distance S2 between the second principal point of the cylindrical lens and the center of the excitation region, and the focal length f of the cylindrical lens light Is such that S1 = n0 / (kS2-n1) S2 = n1 / (kS1-n0) k = n0 / f. Here, n0 is the refractive index of air, and n1 is the refractive index of the waveguide.

In such a configuration, since the image of the exit surface of the rectangular waveguide 15 is formed in the dye solution 2, the intensity distribution of the excitation light P in the dye solution 2 is uniform and the dye laser It can match the beam width of the light D. Therefore, in this configuration, the conversion efficiency from the excitation light P to the dye laser light D can be further improved, and the intensity distribution of the dye laser light D can be flattened. The exit surface of the rectangular waveguide 15 may be a lens surface, and may be configured as a combination lens with a cylindrical lens processed into the waveguide 7.

Embodiment 16 FIG. FIG. 41 is a plan view showing a configuration of a dye laser device as a liquid laser device according to Embodiment 16 of the present invention, and FIG. 42 is a sectional view taken along line AA of FIG. In the fifteenth embodiment, the configuration in which the excitation light P is shaped by the beam homogenizer 15 and transferred into the dye solution 2 has been described. However, in the sixteenth embodiment, as shown in FIG. The thickness on the solution side was made to match the beam width of the dye laser beam D, and the exit side of the waveguide 7 was used as a beam homogenizer 15.

The thickness of the waveguide 7 on the incident side of the excitation light P is made larger than the beam width of the excitation light P as in the first, second to fifth and eleventh to fifteenth embodiments. Light is condensed in a direction perpendicular to the traveling direction of the laser beam. At a position where the excitation light P becomes narrower in the waveguide 7 than the width of the dye laser light D,
The thickness of the waveguide 7 is made equal to the width of the dye laser light D, and the excitation light P is reflected many times up to the dye solution 2 also in the direction perpendicular to the dye laser light traveling direction. Thereby, the intensity distribution of the excitation light P in the dye solution 2 can be made uniform and coincide with the beam width of the dye laser light D.
Conversion efficiency can be further improved, and the intensity distribution of the dye laser beam D can be flattened.

[0054]

According to the present invention, the intensity distribution of the excitation light in the dye solution is flattened, and even if the excitation light is transmitted through a plurality of optical fibers,
A liquid laser device can be provided in which the irradiation positions of the excitation light emitted from the respective fibers are made coincident with the dye solution, and the excitation or the amplification characteristics of the dye laser are equalized even when the excitation is performed from any of the fibers.

According to the first aspect of the present invention, since the waveguide for guiding the excitation light to the laser medium is provided, and the emission surface of the waveguide is in contact with the laser medium, the intensity of the excitation light in the laser medium is increased. Even if the distribution is flattened and the excitation light is moved in the plane of incidence of the waveguide, the oscillation or amplification characteristics of the laser can be made equal. Further, even when the pumping light is transmitted through a plurality of optical fibers, the irradiation position of the pumping light emitted from each fiber in the laser medium can be matched, and the laser oscillation or Amplification characteristics can be equalized.

According to the second aspect of the present invention, the waveguide is configured to have a single focusing means for guiding the excitation light to the laser medium and to have a waveguide structure in a direction perpendicular to the focusing direction. Therefore, similar to the effect of the first aspect of the present invention, since a waveguide for guiding the excitation light to the laser medium is provided, and the emission surface of the waveguide is in contact with the laser medium, the excitation light is emitted in the laser medium. The intensity distribution of the laser beam is flattened, the laser oscillation or amplification characteristics can be equalized even if the pumping light is moved within the plane of incidence of the waveguide, and even when the pumping light is transmitted through a plurality of optical fibers. The irradiation position of the excitation light emitted from each fiber in the laser medium can be matched, and the oscillation or amplification characteristics of the laser can be made equal regardless of the excitation from any fiber.

According to the third aspect of the present invention, since the waveguide is provided in a shape contracted in the direction of the excitation light travel, in addition to the effect of the first aspect of the present invention, the excitation light having a large beam width is provided. Can efficiently irradiate the laser medium.

According to the fourth aspect of the present invention, the main body of the cell is made of metal, a window transparent to the laser light is provided on the optical path of the laser light, and the waveguide is bonded to the main body of the cell. Therefore, in addition to the effects of the first to third aspects of the present invention, the device can be easily handled.

According to the fifth aspect of the present invention, the main body of the cell is made of metal, a window transparent to the laser light is provided on the optical path of the laser light, and the waveguide is provided with packing between the main body of the cell and the waveguide. With this configuration, in addition to the effects of the first to third aspects of the present invention, the waveguide can be easily replaced.

According to the sixth aspect of the present invention, since the main body of the cell is made of a material transparent to the laser beam and the waveguide has a refractive index larger than that of the main body of the cell, In addition to the effects of the first to third aspects of the present invention, since the cell body is transparent, the laser medium can be observed.

According to the seventh aspect of the present invention, the waveguide is surrounded by the protective plate made of a material having a lower refractive index than the waveguide. At times, damage to the waveguide can be prevented.

According to the eighth aspect of the present invention, the protective plate is shorter than the waveguide, and the protective plate serves as a means for fixing the waveguide and controlling the position of the waveguide. In addition to the effect described above, the installation accuracy of the waveguide can be improved.

According to the invention of claim 8, since the protection plate is provided with a flange for fixing the waveguide and as a means for controlling the position of the waveguide, the protection plate is provided with a flange. In addition to the effect, the installation accuracy of the waveguide can be further improved.

According to the tenth aspect, since a part of the excitation light is reflected at least once or more on the surface in the longitudinal direction of the cross section of the waveguide, the effect of each of the first to ninth aspects can be obtained. In addition, the intensity distribution of the excitation light can be further flattened in the laser medium.

According to the eleventh aspect of the present invention, since the light from a plurality of light sources having different pulse phases is guided to the waveguide as the excitation light and the excitation light is synthesized in the waveguide, the invention is characterized in that: In addition to the effects of the tenth aspects, the present invention can be applied to the oscillation or amplification of laser light having a frequency higher than the repetition frequency of the excitation light.

According to the twelfth aspect of the present invention, the condensing means and the waveguide are arranged independently of each other.
In addition to the effect of the invention of claim 2, it is possible to easily adjust the intensity distribution of the excitation light in the laser medium.

According to the thirteenth aspect of the present invention, the light condensing means has the independent first light converging means and the second light converging means integrated with the waveguide. , Claim 2
In addition to the effects of the invention described above, the aberration at the time of condensing the excitation light can be reduced by the combination of the two condensing optical systems.

According to the fourteenth aspect of the present invention, since the condensing means has a hologram formed on the excitation light incident surface of the waveguide, in addition to the effects of the first and second aspects, The excitation light can be focused to an arbitrary intensity distribution in the laser medium, and the shape of the excitation region should match the shape of the laser light even when the laser light travels while diverging or converging in the laser medium. Thus, the energy conversion efficiency from the excitation light to the laser light can be improved.

According to the fifteenth aspect of the present invention, since the optical fiber for guiding the excitation light is provided and the image of the exit surface of the optical fiber is formed on the laser medium by the condensing means,
In addition to the effects of the first to sixth and twelfth to fourteenth aspects, the intensity distribution of the excitation light in the laser medium can be matched with the beam width of the laser light, and the conversion efficiency from the excitation light to the laser light can be improved. Can be improved.

According to the sixteenth aspect of the present invention, there is provided a configuration in which a beam homogenizer for uniformizing the intensity distribution of the excitation light is provided, and an image of the exit surface of the beam homogenizer is formed on the laser medium by the condensing means. Therefore, claims 1 to 6,
In addition to the effects of the invention of claims 12 to 14, the intensity distribution of the excitation light in the laser medium can be made uniform and equal to the beam width of the laser light, and the conversion efficiency from the excitation light to the laser light can be improved. And the intensity distribution of the laser beam can be flattened.

According to the seventeenth aspect, the waveguide is larger than the beam width of the excitation light on the plane of incidence of the excitation light, and is condensed in the waveguide at a position smaller than the beam width of the laser light by the converging means. Since the width of the waveguide in the light condensing direction is substantially equal to the beam width of the laser beam, the laser medium is provided in addition to the effects of the first to sixth and twelfth to fourteenth aspects. In addition to being able to match the intensity distribution of the excitation light with the beam width of the laser light,
Compared with the invention of claim 16, the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view showing another modification of the first embodiment.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a plan view showing a second embodiment.

6 is a sectional view taken along line AA of FIG.

FIG. 7 is a plan view showing another modification of the second embodiment.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

FIG. 9 is a plan view showing another example of the device according to the second embodiment.

FIG. 10 is a sectional view taken along the line AA of FIG. 9;

FIG. 11 is a plan view showing a third embodiment.

FIG. 12 is a sectional view taken along line AA of FIG. 11;

FIG. 13 is a plan view showing another modification of the third embodiment.

14 is a sectional view taken along the line AA of FIG.

FIG. 15 is a plan view showing a fourth embodiment.

16 is a sectional view taken along line AA of FIG.

FIG. 17 is a plan view showing another modification of the fourth embodiment.

18 is a sectional view taken along line AA of FIG.

FIG. 19 is a plan view showing a fifth embodiment.

20 is a sectional view taken along line AA of FIG.

FIG. 21 is a plan view showing another modified example of the fifth embodiment.

FIG. 22 is a sectional view taken along line AA of FIG. 21.

FIG. 23 is a plan view showing the sixth embodiment.

24 is a sectional view taken along line AA of FIG.

FIG. 25 is a plan view showing the seventh embodiment.

26 is a sectional view taken along line AA of FIG.

FIG. 27 is a plan view showing the eighth embodiment.

28 is a sectional view taken along line AA of FIG.

FIG. 29 is a partially enlarged plan view showing the ninth embodiment.

FIG. 30 is a partially enlarged plan view showing another example of the ninth embodiment.

FIG. 31 is a plan view showing the tenth embodiment. Another modification

FIG. 32 is a plan view showing another example of the tenth embodiment.

FIG. 33 is a plan view showing the eleventh embodiment.

34 is a sectional view taken along line AA of FIG.

FIG. 35 is a plan view showing a twelfth embodiment.

36 is a sectional view taken along line AA of FIG. 35.

FIG. 37 is a plan view showing a thirteenth embodiment.

FIG. 38 is a sectional view taken along line AA of FIG. 37.

FIG. 39 is a partially enlarged plan view showing the fourteenth embodiment.

FIG. 40 is a partially enlarged plan view showing the fifteenth embodiment.

FIG. 41 is a plan view showing a sixteenth embodiment.

42 is a sectional view taken along line AA of FIG. 41.

FIG. 43 is a configuration diagram showing a conventional dye laser device.

FIG. 44 is a diagram showing a refractive index distribution of a prismatic lens of a conventional dye laser device.

FIG. 45 is a configuration diagram showing a cross section of a conventional dye laser device.

[Explanation of symbols]

1 dye cell, 2 dye solution, 3 slit, 4 excitation area, 5 dye laser window, 6 optical fiber, 7 waveguide, 8 adhesive, 9 packing, 10 protective plate, 11
Waveguide support block, 12 pump laser, D dye laser beam, P pump laser beam, no refractive index of air, n1
The refractive index of the waveguide, the refractive index of the n2 dye cell, the maximum incident angle of the θ0 excitation light into the waveguide, the maximum refractive angle of the θ1 excitation light in the waveguide, the width of the w waveguide, the length of the L waveguide, d
Core diameter of optical fiber, repetition frequency of fp excitation laser, repetition frequency of fd dye laser, 21 prismatic lens, 22 mount, 23 refractive index distribution, 24 support.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yukio Sato 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Kazuhiko Hara 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Rishi Electric Co., Ltd. (72) Inventor Ichiro Kobayashi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Shuichi Fujita 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Co., Ltd. F-term (reference) 5F072 AC02 JJ20

Claims (17)

[Claims] An excitation region is formed in the slit by irradiating excitation light from a predetermined direction to a cell having a slit for enclosing or circulating a laser medium to excite the laser medium, and the excitation region has a gain. A liquid laser device that performs laser oscillation or amplification as a medium, comprising: a waveguide for guiding the excitation light to the laser medium, wherein an emission surface of the waveguide is in contact with the laser medium. 2. The light guide according to claim 1, wherein the waveguide has a single focusing means for guiding the excitation light to the laser medium and a waveguide structure in a direction perpendicular to the focusing direction. 1
3. The liquid laser device according to claim 1. 3. The waveguide according to claim 1, wherein the waveguide has a shape that contracts in a direction in which the excitation light travels.
3. The liquid laser device according to claim 1. 4. The cell body according to claim 1, wherein the main body of the cell is made of metal, a window transparent to the laser light is provided on the optical path of the laser light, and the waveguide is bonded to the main body of the cell. The liquid laser device according to claim 3. 5. The cell body is made of metal, a window transparent to the laser light is provided on the optical path of the laser light, and the waveguide is provided with a packing between the cell and the cell body. The liquid laser device according to claim 1. 6. The cell according to claim 1, wherein the body of the cell is made of a material transparent to laser light, and the refractive index of the waveguide is larger than the refractive index of the body of the cell. A liquid laser device according to any one of the above. 7. The liquid laser device according to claim 1, wherein the waveguide is surrounded by a protective plate, and the protective plate is made of a material having a lower refractive index than the waveguide. . 8. The liquid laser according to claim 1, wherein the protection plate is shorter than the waveguide, and the protection plate is used as a means for fixing the waveguide and controlling the position of the waveguide. apparatus. 9. The liquid laser according to claim 1, wherein a flange is provided on the protection plate so that the protection plate serves as a means for fixing the waveguide and controlling the position of the waveguide. apparatus. 10. A cross-sectional longitudinal surface of a waveguide,
10. The liquid laser device according to claim 1, wherein a part of the excitation light is reflected at least once. 11. The method according to claim 1, wherein light from a plurality of light sources having different pulse phases is guided to the waveguide as excitation light, and the excitation light is synthesized in the waveguide. The liquid laser device according to claim 1. 12. The liquid laser device according to claim 1, wherein the condensing means and the waveguide are arranged independently. 13. The method according to claim 1, wherein the light collecting means is a combined optical system of an independent first light collecting means and a second light collecting means integrated with the waveguide. A liquid laser device according to claim 1. 14. The liquid laser device according to claim 1, wherein the condensing means is a hologram formed on an excitation light incident surface of the waveguide. 15. An apparatus according to claim 1, further comprising an optical fiber for guiding the excitation light, wherein an image of an exit surface of the optical fiber is formed on a laser medium by a light condensing means. A liquid laser device according to claim 14. 16. A beam homogenizer for making the intensity distribution of excitation light uniform, wherein an image of an exit surface of the beam homogenizer is formed on a laser medium by a light condensing means. The liquid laser device according to any one of claims 1 to 6, and 12 to 14. 17. A waveguide in a light-collecting direction at a position where the waveguide is larger than the beam width of the pump light on the plane of incidence of the pump light and smaller than the beam width of the laser light by the light-collecting means in the waveguide. The liquid laser device according to any one of claims 1 to 6, wherein the width is substantially equal to the beam width of the laser light.