JP2003283025A - Double wavelength laser device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double wavelength laser device which simultaneously obtain a double wavelength laser beam from one solid crystal and is small-sized, reliable, inexpensive, and excellent in efficiency. <P>SOLUTION: In the laser device provided with an exciting semiconductor laser oscillator 6 to generate the laser beam by exciting the solid crystal of a laser medium and the laser medium, a condensing lens 5, a 1/2 wavelength plate 8, a reflection mirror 1 to resonate the beam generated from the laser medium, a laser output mirror 4, and a Q switch 3, a PbWO<SB>4</SB>monocrystal which is a Raman crystal 2 is used for the solid crystal of the laser medium, an AOQ switch is used for the Q switch 3, and double wavelength laser oscillation is simultaneously executed by one solid crystal. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to laser oscillation.
Stokes light and antis
Related to dual-wavelength laser devices that emit talks light
It is. [0002] 2. Description of the Related Art In a fluorescence microscope, laser light of two wavelengths is used.
Utilizing the nonlinearity of dye emission,
Attempts have been made to improve the releasability. Conventionally, two wavelengths
To obtain laser light simultaneously, two types of laser
Was required. However, using two types of laser devices
When used, fluorescent microscopes require a larger device and cost
Will also increase. [0003] Laser light of two wavelengths in a general laser device
Tunable laser devices have also been put into practical use to obtain
However, this laser device uses a diffraction grating to change the wavelength.
The device is complicated and large because the
Become. Also, even if a tunable laser device is used,
It is not possible to obtain two wavelengths of laser oscillation simultaneously
No. On the other hand, two wavelengths can be obtained using a Raman crystal.
Laser devices are also being considered. But this laser
The device is a crystal (for example, Nd: YA)
G) divides the laser beam emitted from
The other one passes through the Raman crystal and only the Raman shift
Because it is a method of obtaining a shifted oscillation, the laser light is divided
And optical system to guide the split light to the Raman crystal
And extra Raman crystals are required, making the equipment complicated.
I have to grow. [0005] SUMMARY OF THE INVENTION As described above, one fixed
Laser that can obtain two wavelengths of laser light at the same time in a body crystal
-The device has not been put into practical use. Solve this problem
For PbWO_FourDoping the crystal with Nd
-Dual wavelength laser device used as a solid crystal of medium
(Japanese Patent Application No. 2001-51575) has been developed. However, in this two-wavelength laser device,
Use normal Q switch such as Cr: YAG as force amplification means
In fields where oscillation efficiency is poor and high output is required,
Sometimes there was a lack of power. The present invention relates to a laser device.
To solve the above problem in
Can simultaneously obtain two wavelengths of laser light from the crystal.
Small, reliable, inexpensive and efficient two-wavelength laser device
The purpose is to provide a device. [0007] SUMMARY OF THE INVENTION A dual wavelength laser of the present invention
The device consists of a solid crystal of the laser medium and a Raman crystal.
bWO_FourUse a single crystal to excite the laser medium
A light source for excitation for generating laser light and a laser medium.
Optical resonance means for resonating light generated from the material.
Sometimes a two-wavelength laser device that performs two-wavelength laser oscillation
Use an AOQ switch as output amplification means
This solves the above problem. In this two-wavelength laser device, the laser medium
PbWO as Raman crystal_FourUse a single crystal
Nd, Yb, Er, P
Inclusion of r, Eu, Tb, Sm, etc. in solid crystals
Laser light emitted from a solid crystal and Raman shift
Approximately 900cm^-1Raman-transformed Stokes beam
Simultaneously oscillate anti-Stokes light, and use it as output amplification means.
By using the AOQ switch, the narrow pulse width
Obtain a pulse laser beam with a large head value. When Nd is used as a laser active substance
Is 1058 nm (9451.8 cm ^-1) And 900c
m^-1Offset 1170 nm (8547.0 cm^-1)
Emissions with peaks were observed, and two wavelengths
Laser oscillation light is generated. Laser actives in solid crystals
In general, the higher the content, the higher the efficiency.
Good. However, PbWO_FourLaser active in single crystal
If the concentration exceeds 10 mol%, processing such as cutting and polishing may occur.
Will not be able to. Also, PbWO_FourLaser active substance concentration in
When the degree exceeds 18 mol%, a single crystal cannot be formed. Follow
And PbWO_FourLaser active substance concentration in the solution is 10 mol%
Must be less than or equal to 5 mol%
Is preferred. On the other hand, PbWO_FourLaser activity in single crystals
Laser oscillation when the substance concentration is less than 0.01 mol%
No longer occurs, the laser active substance concentration is 0.01
Mol% or more, and 0.05 mol% or less.
More preferably, it is above. Place to use for fluorescence microscope
In the case of a laser with a wavelength between 500nm and 600nm
Light is desirable. Nd used as laser active material
In case, PbWO_FourLaser oscillation generated from single crystal and
Raman-shifted light is used to generate SHG elements such as LN and harmonics
By passing it through the device, a double harmonic is obtained.
and 585 nm light can be obtained simultaneously. To obtain light of a shorter wavelength, use SHG
Third and fourth harmonics from devices and harmonic generators
You can use. Therefore, two wavelengths of laser light are
Even if you get the extra equipment other than the laser oscillator
It is unnecessary, and the size and price of the laser device can be reduced.
Wear. [0012] FIG. 1 shows an embodiment of the present invention.
Figure 2 shows the configuration of a two-wavelength laser device.
It is a figure showing a spectrum of output laser light of an apparatus. This
Some laser devices are used as solid crystals in the laser medium.
PbWO which is a man crystal_FourSingle crystal 2 is used.
In addition, the laser medium is excited to generate laser light 7.
Semiconductor laser oscillator 6 as a light source means for exciting
Condensing lens 5 and 1/2 wavelength plate for adjusting light polarization direction
8. An optical resonator that resonates light generated from a laser medium
A reflecting mirror 1 and a laser output mirror 4 are provided as steps.
Further, a Q switch 3 is provided on the optical axis of the laser light 7.
Have been. [0013] PbWO_FourLaser active material for single crystal 2
As Nd. Semiconductor laser oscillator 6
Is a 20 Hz pulse oscillation type semiconductor laser oscillator.
, A semiconductor laser with an absorption wavelength of Nd of 802 nm
Oscillates light (excitation light). The condenser lens 5 is provided with
Focus on PbWO_FourSingle crystal 2 with its optical axis at 90 degrees
Incident from the opposite direction. [0014] PbWO_FourSurface of single crystal 2 on which excitation light is incident
2B has an anti-reflection coating for 802 nm excitation light
802nm excitation is applied to the surface 2A facing the surface.
Mirror surface coating for light emission. This mirror coat
Reflects 802 nm excitation light, and PbWO_FourSingle crystal 2
To increase the number of routes and use them effectively. Ma
PbWO_FourOn the optical axis surface 2C of the single crystal 2, a laser
Antireflection core for the oscillation wavelength 1.06 μm of the conductive substance Nd
The seat is decorated. Note that PbWO_FourLes contained in single crystal 2
If the active substance is different from Nd, PbWO_Foursingle
The surface of the crystal 2 on which the excitation light is incident, 2B
Anti-reflection coating for the absorption wavelength of conductive substances, facing it
Surface 2A has a wavelength corresponding to the absorption wavelength of the laser-active substance.
Mirror coating is required. Furthermore, PbWO_FourSimple connection
The oscillating wave of the laser active substance is placed on the optical axis surface 2C of crystal 2.
It is necessary to apply an anti-reflection coating to the length. Also, PbWO_FourInjection of excitation light into single crystal 2
The launch direction need not be a direction at 90 degrees to the optical axis.
If the angle deviates from the direction of the angle,
This is disadvantageous because the loss of incident energy increases. Follow
The incident direction of the excitation light must be within 90 ° ± 45 ° with the optical axis.
Is desirable. Of course, the solid laser
Can be incident from the optical axis direction, which is a general method
Absent. An AOQ switch is used for the Q switch 3.
ing. TeO_TwoUse crystal, power frequency 10kHz
Used in. Excitation semiconductor by pulse generator
Synchronous with body laser and same as semiconductor laser for excitation 1
The Q switch 3 was turned on at a frequency of 00 Hz. Two waves in Fig. 1
PbWO with long laser device_Four1 mol% of N
PbWO containing d_FourSingle crystal (3 × 3 × 20mm)
Used, 100Hz pulse oscillation type with 802nm wavelength
When the semiconductor laser light was irradiated as excitation light,
As shown in FIG.
Simultaneous generation of laser light 7 with a wavelength of 170 nm was confirmed.
Was. As shown in Table 1, an AOQ switch is used.
It was confirmed that the oscillation efficiency improved. [0019] [Table 1] Excitation light: 9mJ Wavelength: 802nm Frequency: 100H
z pulse width: 200 μs Further, excitation of continuous oscillation at a wavelength of 802 nm
Similar results were obtained when using light. Oscillate
As a result of analyzing the laser beam 7, the oscillation at 1058 nm was N
d, laser oscillation light at 1170 nm is 105
8 nm light is subjected to Raman scattering inside the crystal (Raman shift of about 9
00cm^-1) And oscillate (Raman laser)
Turned out to be. Further, each light passes through a harmonic element.
It was also confirmed that half the wavelength of light could be extracted. Change
In addition, Yb, Eu, Pr, Tb, E
Even if r and Sm are used, the
Emission and Raman-scattered Stokes light and anti-strike
The emission of the peak light was simultaneously observed. [0022] According to the dual wavelength laser device of the present invention,
To obtain two wavelengths of laser light simultaneously from one solid crystal
As a result, the size and cost of the device can be reduced. Leh
Nd, Yb, Er, Pr, Eu, T
b, Sm, etc. contained in the solid crystal
Laser light oscillated from the laser and the Raman shift amount is about 900
cm^-1Raman-transformed Stokes light and anti-Storm
Light can be emitted simultaneously. Light source for excitation
The use of semiconductor lasers as a means is all-solid and requires few parts.
Realization of a compact and highly reliable two-wavelength laser device
Because the AOQ switch is used for the Q switch,
A pulse laser beam with a narrow peak and a large peak value can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a two-wavelength laser device according to an embodiment of the present invention. FIG. 2 is a diagram showing output laser light of a two-wavelength laser device. [Description of Signs] 1 Reflecting mirror 2 PbWO ₄ Single crystal 3 Q switch (AOQ switch) 4 Laser output mirror 5 Condensing lens 6 Semiconductor laser oscillator 7 Laser light 8 1/2 wavelength plate

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yoshiyuki Thin             1-25-13 Kanondai, Tsukuba, Ibaraki Furukawa, Japan             Machinery & Materials Co., Ltd.             Inside (72) Inventor Takashi Omatsu             5-10-9 Hirado, Totsuka-ku, Yokohama-shi, Kanagawa F term (reference) 5F072 AB20 KK01 KK11 KK30 PP07                       QQ05 QQ07 SS08 SS10

Claims (1)

Claims: 1. An excitation light source means for generating a laser beam by exciting a laser medium using a PbWO ₄ single crystal as a Raman crystal as a solid crystal of the laser medium, and a laser medium. A two-wavelength laser device comprising: an optical resonating means for resonating generated light, and simultaneously performing two-wavelength laser oscillation, wherein an AOQ switch is used as an output amplifying means.