JPH0417379A - Solid-state laser by laser diode pumping - Google Patents

Abstract

PURPOSE:To provide a solid-state laser having a high wavelength conversion efficiency, energy efficiency, and stabilized output by using a laser rod with resonator mirrors at both ends, and drawing either the second harmonic or a wavelength-converted beam of produced laser light. CONSTITUTION:A laser diode 11 has a coated spherical rod end 13a, as an input resonator mirror, which reflects a laser beam 17 and transmits a pumping laser beam 10. The other rod end has a mirror finish and coating to reflect a laser beam and transmit the second harmonic 15'. A laser beam 15 is confined between both ends 13a and 13b of the resonator for laser oscillation. The wavelength of the laser beam is converted in the NYAB rod 13, which is a laser medium having a waveconverting function.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a laser diode-pumped solid-state laser that pumps a solid-state laser rod with a semiconductor laser (laser diode).
The solid-state laser rod itself has an optical wavelength conversion function,
The present invention relates to a laser diode-pumped solid-state laser that converts the wavelength of a solid-state laser oscillation beam into its second harmonic, or the solid-state laser oscillation beam and another laser beam into an optical wavelength-converted wave such as a sum frequency thereof.

(Prior art) For example, S P I E Vol, 1104 ploo
As described in March 1989, Nd(
Nd:C is used as a solid-state laser rod doped with rare earth elements such as neodymium (neodymium) and has an optical wavelength conversion function.
0ANP, Nd: PNP etc. are well known. Also, as such a solid-state laser rod, see p132 of the same magazine.
As described in Nd:LiNbO2゜NYA
B (Nd -Y+--AI!3 (BO3)4
X-0,04~0.08) etc. are also known, and these are Self-Frequency-Doubling
It's called Crystal.

As a laser diode pumping solid-state laser using these, SPI E Vol. 1104
p132 March 1989 and Laser Research Vo
1.17 NO, 12p4g (1989), it is known that a NYAB crystal is used and the second harmonic of the oscillated laser beam is obtained by laser diode bombing. Also J, Opt, Soc,
Am Vol, 3 p140 (19g[i),
It has been shown that Nd:Mg02LiNbO3 is excited by a dye laser with a wavelength of 0.60 μm to obtain the second harmonic of the oscillated laser beam.

Furthermore, for example, S P I E Vol, 1104
p13 March (1989), a Nd-doped YAG laser is equipped with a solid-state rod and a KTP single crystal that converts the wavelength of the solid-state laser oscillation beam in its resonator, thereby converting the sum of the solid-state laser oscillation beam and the pumping light. It has been shown that the frequency can be obtained.

(Problem to be Solved by the Invention) However, in conventional solid-state lasers equipped with such a wavelength conversion function, a nonlinear optical crystal solid-state laser rod and an output mirror oscillate the oscillated laser beam into a single longitudinal mode to convert the wavelength-converted wave. Optical elements such as etalon plates and wave plates, which have the function of stabilizing power, are arranged separately.
In addition, it was processed, polished, and coated as a separate laser component. For this purpose, the processed surface has scattering of the oscillated laser beam and absorption and scattering by each coating film.

Reflection, etc. occur, and furthermore, internal loss within the resonator becomes extremely large, at several percent or more, due to absorption inside each component. These internal losses increase as the number of parts increases.

Therefore, there was a problem in that the oscillation laser power within the resonator was reduced, and as a result, the wavelength conversion efficiency was reduced.

In addition, because the internal loss mentioned above was previously as high as several percent,
As a pump light source for solid-state lasers, high-power arrays and
Lasers are commonly used.

That is, by doing so, the loss within the resonator is covered to obtain high-output internal power within the resonator, thereby improving the wavelength conversion efficiency. However, in conventional array lasers, the spectral linewidth is several nanometers, so the oscillation efficiency of solid-state lasers is low, which leads to a decrease in energy utilization efficiency.

In particular, etalon plates and wavelength plates inserted into the resonator to stabilize the power of wavelength-converted waves greatly increase internal loss, so a high-power array laser or broad-area laser must be used. I didn't get it. Also,
If these wavelength plates and etalon plates are removed in order to eliminate insertion loss, when obtaining the second harmonic of the oscillated laser beam, due to mode competition between the longitudinal modes of the oscillated laser beam due to nonlinear optical elements. There was a problem that the power became unstable.

The present invention has been made in view of the above circumstances, and aims to provide a laser diode pumped solid-state laser that has high wavelength conversion efficiency, good energy utilization efficiency, and stable power of wavelength exchanged waves. That is.

(Means and effects for solving the problem) First aspect of the present invention
As mentioned above, the laser diode pumped solid-state laser uses a semiconductor laser to pump a solid-state laser rod that is doped with rare earth elements such as Nd and has an optical wavelength conversion function. is the resonator mirror, and the second harmonic of the oscillated laser beam or
It is characterized by extracting wavelength-converted waves such as the sum frequency of a semiconductor laser beam and an oscillation laser beam.

Further, the second laser diode pumping solid-state laser of the present invention is a laser diode-pumping solid-state laser in which a solid-state laser rod doped with rare earth elements such as Nd and having an optical wavelength conversion function is pumped by a semiconductor laser in the same manner as described above. , an optical element such as an etalon or a wavelength plate, which has a function of stabilizing the power of the wavelength-converted wave, is pasted and integrated on one end surface of the solid-state laser rod, and one side of the optical element is used as the resonator mirror of the solid-state laser. On the other hand, the other end surface of the solid-state laser rod is used as another resonator mirror to form a resonator, thereby converting the wavelength of the second harmonic of the oscillated laser beam or the sum frequency of the semiconductor laser beam and the oscillated laser beam. It is characterized by extracting waves.

Further, the third laser diode pumped solid-state laser of the present invention is a laser diode-pumped solid-state laser in which a solid-state laser rod doped with a rare earth such as Nd and having an optical wavelength conversion function is pumped by a semiconductor laser in the same manner as described above. , optical elements such as etalons and wavelength plates that have the function of stabilizing the power of wavelength-converted waves are pasted and integrated between two solid-state laser rods, and the outer end surfaces of these solid-state laser rods are used as resonator mirrors. , the second harmonic of the oscillated laser beam, or
It is characterized by extracting wavelength-converted waves such as the sum frequency of a semiconductor laser beam and an oscillation laser beam.

Further, the fourth laser diode pumped solid-state laser of the present invention is a laser diode-pumped solid-state laser in which a solid-state laser doped with a rare earth such as Nd and having an optical wavelength conversion function is pumped by a semiconductor laser in the same manner as described above. In this method, multiple optical elements such as etalons and wavelength plates, which have the function of stabilizing the power of wavelength-converted waves, are attached to one or more solid laser rods and integrated, and the end face of any of these optical components is attached to one or more solid laser rods. A resonator is constructed using the resonator mirror, and the second harmonic of the oscillated laser beam or
It is characterized by extracting wavelength-converted waves such as the sum frequency of a semiconductor laser beam and an oscillation laser beam.

The above solid-state laser rod is a normal Self-Fr
A material called equivalence-Doublejng Crystal, namely the aforementioned NYAB, Nd:Mg
O: Li NbO3, Nd: PNP, etc. can be used. In addition, KTP, which is an inorganic material,
, β-BBO.

It is also possible to use nonlinear optical materials for wavelength conversion, such as Li B203 , KNb 03 , and chalcobyrite-based semiconductors doped with rare earth elements such as Nd.

In particular, KTP has a large nonlinear optical constant, and the temperature tolerance range is
Since the angle tolerance is large, high wavelength conversion efficiency can be achieved.

Furthermore, as represented by Nd:PNP, NPP (N
-(4-nitrophenyl)-L-prolinol), NP
AN (N-(4-nitrophenyl)N-methylaminoacetonitrile), PRA (3,5-dimethyl-1-(4-nitrophenyl)pyrazole) disclosed in JP-A-62-210432, etc. Organic nonlinear optical materials doped with rare earth elements can also be used. Especially P
RA has a larger nonlinear optical constant than KTP, and has a larger temperature tolerance range, so it can achieve high wavelength conversion efficiency.

By using these solid-state laser rods and using both end faces as resonators, the number of parts is reduced, there are only two surfaces (processed and polished surfaces and coated surfaces), and there is only one absorption medium for the laser oscillation beam. Internal loss can be reduced. As a result, the internal power of the oscillated laser beam increases, and the wavelength conversion efficiency is significantly improved. In addition, since the resonator length is several mm, the number of longitudinal modes is reduced, and a single mode can be achieved.Longitudinal mode competition via the nonlinear optical crystal is eliminated, and the power of the wavelength-converted wave can be stabilized.

Furthermore, even when the power of the wavelength-converted wave is forcibly stabilized by integrating an optical element into a solid-state laser rod, absorption and scattering occur due to the elimination of input and output mirrors.

Internal loss of the oscillated laser beam due to reflection is reduced. As a result, the internal power of the oscillated laser beam increases, and the wavelength conversion efficiency is significantly improved.

Of course, it is also possible to stabilize the power.

In addition, the efficiency when generating the sum frequency of a semiconductor laser beam and a solid-state laser oscillation beam is lower than the efficiency of the second harmonic due to the low power level of the semiconductor laser beam (this was not practical. In the invention, as the internal loss of the oscillating laser beam is reduced and its internal power is increased, it is possible to achieve high efficiency even in the case of sum frequency generation.

In the laser diode pumping solid-state laser of the present invention, preferably a single transverse mode or single longitudinal mode semiconductor laser is used as the pumping semiconductor laser. In the present invention, as described above, the internal loss can be extremely reduced, so that sufficient wavelength conversion efficiency can be obtained even when pumping with low power by these semiconductor lasers. Furthermore, these single transverse mode and single longitudinal mode semiconductor laser beams have a spectral linewidth of 0,1 nm or less, which is narrower than the aforementioned broad area laser or array laser, so they are sufficiently absorbed by the solid-state laser. The oscillation efficiency of the solid-state laser can be increased, and therefore the energy usage efficiency can be improved. Furthermore, unlike the case of using an array laser, light can be focused up to the diffraction limit, so mode matching between the pumping light and the oscillating laser light is improved, and oscillation efficiency can also be improved from this point of view. Furthermore, in the case of sum frequency generation, there is a problem that the sum frequency of the array laser beam and the oscillation laser beam cannot be focused well because the array laser beam is not a diffraction-limited beam. With a single transverse mode laser, it is possible to obtain a diffraction-limited beam, which can be focused well.

As described above, the present invention provides a compact and highly efficient laser diode pumped solid-state laser.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 shows a laser diode pumped solid state laser according to a first embodiment of the invention. This laser diode pumping solid-state laser is a semiconductor laser 1 that emits a laser beam lO as pumping light.
1 (single longitudinal mode, single transverse mode laser 2 or less, LD
) and a selfoc rod lens 12 that collimates and focuses the diverging laser beam 10.
and SC1f-Frequency-Doubling
NYA B which is Crystal.

It consists of RAD 13. Each of the elements described above is mounted and integrated in a common housing (not shown). Note that the temperature of the LDII is controlled to a predetermined temperature by the Peltier element 14 and a temperature control circuit (not shown).

This LDII is one that emits a laser beam lO with a wavelength of λ1 to 804 nm. On the other hand, the NYAB rod 13 has doped neodymium atoms excited by the laser beam 10.
Emits a laser beam 15 of λ2-10 (i2 nm).

The resonator is formed only by the NYAB rod 13 with a crystal length Lm of 2 mm. That is, as an input end resonator mirror, the rod end surface 13a on the LDII side has a radius of curvature R=2.
It is formed into a spherical surface with a wavelength of 11062 mm.
n laser beam 15 is well reflected (reflectance 99
．． 9% or more), and the pumping laser beam 10 having a wavelength of 804 nm is well transmitted (transmittance of 99% or more). The other rod end surface 13b of the output side resonator mirror is mirror-polished to a flat surface, and the laser beam with a wavelength of 11062n is well reflected (reflectance of 99.9% or more) on that surface, and the wavelength A coating is applied that allows good transmission of the second harmonic 15' of 531 nm. Therefore, the laser beam 15 with a wavelength of 11062n is confined between the surfaces L3a and 13b of the resonator, causing laser oscillation.

This laser beam 15 is wavelength-converted into a second harmonic 15' whose wavelength is 1/2, that is, 531 nm, in the NYAB rod 13, which is an oscillation medium and has a wavelength conversion function. The NYAB rod 13 has wavelengths of 11062n and 53n.
The crystal is cut so that angular phase matching of TYPEI can be achieved between 1 nm and 1 nm. Resonator output side mirror 13
b is coated as described above, so the second harmonic 15' is efficiently extracted from this resonator.

Here, the wavelength conversion efficiency in the case of the present example is that the output of the semiconductor laser beam 10 which is the pumping light is
When W, the output of the second harmonic 15° is approximately 1.0
It became mW. Despite the very short crystal length of L-2 mni, in this example, the internal loss was reduced to 1% or less, making highly efficient wavelength conversion possible.

Furthermore, since the crystal length is 2 mW, which is a short resonator, the oscillating laser beam easily oscillates in a single longitudinal mode, and as a result, a wavelength-converted wave with stable power can be obtained.

Next, referring to FIG. 2, a second embodiment of the present invention will be described. Note that in FIG. 2, elements that are equivalent to those in FIG. In this example, NY
The AB rod 13 is attached to the copper block 2 on the Peltier element 20
1, and is placed in close contact with the Dll on the copper block 21. With such a configuration, it is possible to encapsulate all the laser components in the LD package. Furthermore, NYAB rod 13, LD
Since it is cooled at the same time by the Veltier element 20 for temperature control,
NYA B rod 1 with fewer parts and temperature control
3 longitudinal mode hops can be suppressed, and it has become possible to almost completely suppress output fluctuations of the second harmonic 15' due to changes in ambient temperature.

Next, a third embodiment of the present invention will be described with reference to FIG. In this example, the second harmonic of higher output is 15°.
In order to obtain
and the radius of curvature of the rod end surface 13a on the input side was set to R-7 mm. As a result, the resonator length has become clearly longer, so that the oscillation laser beam 15 exhibits longitudinal mode multi-oscillation. In order to suppress this, an etalon plate 22 is attached to the output end face 13b as shown in the figure, and this output end face 13
b was coated with the same AR coating as in the first example.

As the pumping light, single longitudinal mode and single transverse mode LDII are used as in the first embodiment, and the collimator lens 23 converts the diverging laser beam 10 into parallel light, and the collimated laser beam It is input to the NYAB rod 13 by a condensing lens 24 that focuses lO.

The oscillating laser beam 15 resonates between the input side end surface 13a of the NYAB rod 13 and one end surface 22a of the etalon plate 22, and oscillates. The output of the second harmonic 15' obtained in this way is the output of the semiconductor laser beam 10
The output was about 5 mW when the output was taken as too mW.

Furthermore, in order to obtain the same shape as the comparative example described later, when the crystal length is L-5 mm and the radius of curvature is R-5 mm, and the other configurations are the same as in this example, a broad area semiconductor laser beam The second harmonic 15' using 1°
When generated, the output was 20 at an input of 4゜OmW.
mW was obtained.

In addition, in order to stabilize the power of the wavelength-converted wave, in addition to using the etalon plate 22 described above, as shown in FIG.
A wavelength plate 25 such as a λ/4 plate may be attached to the AB rod end surface 13b, or the NYAB rod end surface 13b may be attached to the AB rod end surface 13b as shown in FIG.
The etalon plate 22 is attached to the
It is possible to take a configuration such as pasting a . Furthermore, as shown in FIG. 6, an etalon plate 22 is pasted between two NYAB rods 13, 13 to integrate these three elements, or as shown in FIG.
．． At the same time, attach the etalon plate 22 between the
It is also possible to adopt a configuration in which the wavelength plates 25 are attached to the outer end surfaces of the YAB rods 13 and 13, respectively, to integrate these five elements.

The resonator in each of the above cases can be constructed by coating both end faces of the element in the same manner as in the first embodiment.

Next, as a comparative example, the results obtained when using the conventionally known configuration shown in FIG. 8 will be described. NYAB rod 1
3 is cut to a crystal length L-5 mm, and the end face 13a on the LDII side is coated with a reflective coating for a wavelength of 10G2 nm, and a wavelength of 8.
It is provided with an AR rotor for 0.04 nm and constitutes one of the resonator mirrors. The rod end surface 13b on the opposite side is coated with an AR coating for a wavelength of 1[lG2nm, and a wavelength of 531nm.
Anti-reflection coating is applied. The other output mirror 30 constituting the resonator has an inner end surface 30a with R=
It has a radius of curvature of 100mm and a wavelength of 10G4nm.
A reflective coating for the wavelength of 531 nm and an AR coating for the wavelength of 531 nm are applied. An etalon plate 22 is inserted between the resonators.

In the case of this comparative example, since the resonator length is very long, dozens of longitudinal modes oscillate, so a single longitudinal mode is realized by inserting the etalon plate 22. Furthermore, since the resonator length is long, longitudinal mode pops are likely to occur due to changes in ambient temperature, which further increases power instability. In this case, when a 400 mW laser beam 10 (broad area laser) was input, the output of the second harmonic 15° was 6 mW.

The reason why the wavelength conversion efficiency is lower than in the previous embodiment is because there are more components, and the scattering of the oscillated laser beam 15,
This is due to an increase in absorption and reflection loss. As described above, it was confirmed that high wavelength conversion efficiency can be obtained according to the present invention.

Next, an embodiment in the case of sum frequency generation will be described. 9th
The figure shows a laser diode pumped solid state laser according to a fourth embodiment of the invention. This laser diode pumping solid-state laser uses an LD (phased array laser) 41 that emits a laser beam 40 as pumping light. This LD 41 emits a laser beam 40 with a wavelength of 804 nm. Also, a beam splitter 42 is disposed between the collimator lens 23 and the condensing lens 24 , and the beam splitter 42 is provided with a laser beam emitted from another LD (single longitudinal mode laser) 43 and collimated by the collimator lens 44 . Laser beam 4 with a wavelength of 830 nm turned into light
5 is made incident. This laser beam 45 is combined with a laser beam 40 which is pumping light by a beam splitter 42 and is incident on the NYAB rod 13. In addition, each of the above LD41.43 is
The temperature is adjusted to a predetermined temperature by a temperature control circuit 4 and not shown.

N Y A B o Wavelength λ1-1 incident on Rad 13
Laser beam 45 of 130 nm and wavelength λ2 = 1
The oscillation beam 46 of the NYAB rod 13 with a wavelength of 082 nm is
By this NYAB rod 13 itself, the wavelength λ3 = 4
The wavelength is converted to a sum frequency 47 of 68 nm. Furthermore, NYA
The B rod 13 is cut to achieve TYPEI angle phase matching.

Further, both end surfaces 13B, 13b of the NYAB rod 13 are coated with a reflective coating for a wavelength of 10G2 nm, thereby confining the oscillated laser beam 46 of a wavelength of 10 (f2 nm) to cause laser oscillation. Furthermore, wavelengths of 804 nm and 830 nm are provided on the incident end surface 13a.
An AR coating for a wavelength of 4 [i8 nm] is applied to the output end face 13b.

In this way, the IW semiconductor laser beam 40 and
From 100 mW semiconductor laser beam 45, 1 mW
A sum frequency of 47 was obtained.

Further, as in the fifth embodiment shown in Fig. 1θ, the wavelength λ1−
Pumped by a 804 nm semiconductor laser beam 40, and NYAB
Sum frequency 48 (wavelength λ3 - 459 nm) of rod 13's wavelength λ2 = 10B2 nm oscillation laser beam 46
You can also get

Above, 5elf'-Frequency-Double
Although the description has been given using NYAB crystal as an example of ng Crystal, in the present invention, as other crystals, N.
d: MgO: LiNbO2 or Nd: KTP, Nd
: PNP etc. can be used in the same way. These materials may have larger nonlinear optical constants than NYAB crystals, and therefore, by using them, it becomes possible to obtain wavelength-converted waves more efficiently.

Furthermore, in the above embodiments, only the 1 μm band of the Nd oscillation line has been explained, but since the internal loss can be reduced in the laser diode pumped solid-state laser of the present invention, the 0.9 μm band of the Nd oscillation line can be used. , 1.3
Oscillation in the μm band is also possible, and wavelength-converted waves such as the second harmonic of the oscillation beam and the sum frequency of the oscillation beam and the semiconductor laser beam can be efficiently obtained.

Furthermore, as explained in each embodiment, longitudinal mode hops can be suppressed by controlling the temperature of the crystal of the laser medium in order to stabilize the power, but in the case of the present invention, the cavity length can be made very short. , temperature control becomes easier, and power instability due to changes in ambient temperature can be significantly improved.

(Effects of the Invention) As explained in detail above, the laser diode pumping solid-state laser of the present invention uses a solid-state laser rod having a wavelength conversion function as a resonator, or integrates an optical element and the solid-state laser rod to form a resonator. Therefore, it is possible to reduce the internal loss and increase the internal power, thereby improving the wavelength conversion efficiency and obtaining short wavelength laser light with extremely high intensity and high efficiency. In particular, sum frequency generation, which conventionally had low efficiency, can now be achieved with high efficiency.

In the laser diode-pumped solid-state laser of the present invention, the wavelength conversion efficiency is high as described above, so even if a single transverse mode or single longitudinal mode semiconductor laser, which currently has a relatively low output, is used as a pumping source. , it becomes possible to obtain a sufficiently high-intensity short-wavelength laser. In this way, if a single transverse mode, single longitudinal mode semiconductor laser is used as a bombing source, the oscillation efficiency of the solid-state laser increases, so in this case, the energy utilization efficiency becomes particularly high.

Furthermore, even if a relatively low-output semiconductor laser is used as a pumping source as described above, a sufficiently high-intensity short-wavelength laser can be obtained, so the laser diode pumped solid-state laser of the present invention has In order to obtain a wavelength-converted wave with the same light intensity, it is possible to use a lower-power and cheaper semiconductor laser, and by using the solid-state laser rod mentioned above as a resonator, it is possible to make it more compact and reduce the number of parts. Together, this makes it possible to create a low-cost, ultra-compact solid-state laser.

Furthermore, when a sum frequency is generated by the laser diode pumped solid-state laser of the present invention, it becomes possible to focus light up to the diffraction limit, which has been difficult in the past.

[Brief explanation of drawings]

1.2 and 3 are schematic side views showing laser diode pumped solid state lasers according to embodiments 1.2 and 3 of the present invention, respectively; FIGS. 4.5.6 and 7 are
FIG. 8 is a schematic side view showing an example of a combination state of a solid-state laser rod and an optical element in the present invention. FIG. 8 is a schematic side view showing an example of a conventional laser diode pumping solid-state laser. FIG. 6 is a schematic side view of a laser diode pumped solid state laser according to fourth and fifth embodiments of the invention; 10.40.45...Laser beam 11.41.4
3... Semiconductor laser 12... Selfoc rod lens 13 = NYA Bo Rad 13a, 13b mountain rod end surface 14.20... Vertier element 15.46... Solid state laser oscillation beam 15'...
・Second harmonic 22... etalon plate 22a
...Etalon plate end face 23.44...Collimator lens 24...Condensing lens 25...Wave plate 3o...
Output mirror 42...beam splitter 47.
48... Sum frequency Figure 1 Figure 2 Figure 3 Bacteria diagram Figure Figure Figure Figure Figure Figure

Claims (5)

[Claims] (1) In a laser diode-pumped solid-state laser in which a solid-state laser rod doped with rare earth elements such as neodymium and has an optical wavelength conversion function is pumped by a semiconductor laser, both end surfaces of the solid-state laser rod are used as resonator mirrors, and oscillation is caused by this. The second harmonic of the laser beam or
A laser diode-pumped solid-state laser characterized by extracting wavelength-converted waves such as the sum frequency of a semiconductor laser beam and an oscillating laser beam. (2) In a laser diode-pumped solid-state laser, in which a solid-state laser rod doped with rare earth elements such as neodymium and has an optical wavelength conversion function is pumped by a semiconductor laser, the power of the wavelength-converted wave is stabilized on one end surface of the solid-state laser rod. An optical element such as an etalon or a wavelength plate having the function of converting the solid state laser rod is attached and integrated, and one side of the optical element is used as a resonator mirror of the solid-state laser, while the other end surface of the solid-state laser rod is used as another resonator. A laser diode pumped solid-state laser comprising a resonator as a mirror and extracting a wavelength-converted wave such as a second harmonic of an oscillated laser beam or a sum frequency of a semiconductor laser beam and an oscillated laser beam. (3) A laser diode pumping solid-state laser uses a semiconductor laser to pump a solid-state laser rod that is doped with rare earth elements such as neodymium and has an optical wavelength conversion function. An optical element such as a plate is pasted and integrated between two solid-state laser rods, and each outer end surface of these solid-state laser rods is used as a resonator mirror to generate the second harmonic of the oscillated laser beam or
A laser diode-pumped solid-state laser characterized by extracting wavelength-converted waves such as the sum frequency of a semiconductor laser beam and an oscillating laser beam. (4) A laser diode pumping solid-state laser uses a semiconductor laser to pump a solid-state laser rod that is doped with rare earth elements such as neodymium and has an optical wavelength conversion function. A plurality of optical elements such as plates are attached and integrated to one or more solid-state laser rods, and one of the end faces of these optical elements is used as a resonator mirror to form a resonator, and the resulting oscillation laser beam is Second harmonic or
A laser diode-pumped solid-state laser characterized by extracting wavelength-converted waves such as the sum frequency of a semiconductor laser beam and an oscillating laser beam. (5) As a semiconductor laser for obtaining the sum frequency,
5. The laser diode-pumped solid-state laser according to claim 1, wherein a laser diode-pumped solid-state laser according to any one of claims 1 to 4 is used, which is different from a semiconductor laser for causing a laser beam to enter a resonator of the solid-state laser.