JP2009058782A - Laser beam generation device and laser beam generation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam generation device and a laser beam generation method capable of generating a laser beam of short wavelength of wavelength 180 nm or less highly efficiently and stably with a long life. <P>SOLUTION: A third laser beam generation means 300 is irradiated with a first laser beam 101 of wavelength 190 to 200 nm by a first laser irradiation means 100. Meanwhile, the third laser beam generation means 300 is irradiated with a second laser beam 201 by a second laser irradiation means 200. The third laser beam generation means 300 includes CBO crystal. By using the CBO crystal included in the third laser beam generation means 300, sum-frequency mixing of the first laser beam 101 and the second laser beam 201 is performed and, thereby, the third laser beam 301 that is the short wavelength laser beam of wavelength 170 nm to 178 nm is generated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laser light generation apparatus and a laser light generation method.

  The demand for improving the performance of laser light sources for semiconductor manufacturing, wafer inspection, and mask inspection is becoming stricter year by year. In particular, it is no exaggeration to say that there is a demand for a shorter wavelength that is close to the limits of the current technology.

  Currently, in the development of the laser light source, development of a light source that emits a continuous wave having a wavelength of 190 to 200 nm or a high repetitive pulse wave has become the mainstream (Patent Documents 1 to 4, Non-Patent Documents 1 and 2, etc.).

In addition, the CBO (CsB ₃ O ₅ ) crystal has a short wavelength at the fundamental absorption edge of 167 nm, and there are great expectations for its use for generating short-wavelength laser light. Actually, there is an example in which pulsed laser light having a wavelength of 185 nm is generated by sum frequency mixing using a CBO crystal (Non-patent Document 3).

JP 2007-086101 A JP 2007-086104 A US Patent Application Publication No. 2007/0064749 US Patent Application Publication No. 2007/0064750 T.A. Ohtsuki, H. et al. Kitano, H.M. Kawai, and S.K. Owa, "Efficient 193nm generation by eighth harmonic of Er3 + -doped fiber amplifier", in Conference on Lasers and Electro-Optics 2000, postdeadline paper, (Optical Society of America, San Francisco, CA, 2000), p. paper CPD9. H. Kawai, A.A. Tokuhisa, M .; Doi, S .; Miwa, H.M. Matsuura, H .; Kitano, and S.K. Owa, “UV light source using fiber amplifier and non-linear waveguide conversion”, in Conference on Lasers and Electro-Optics 2003, paper CT3, paper CT. Kato, K .; “Tunable UV generation to 0.185 μm in CsB3O5” IEEE Journal of Quantum Electronics, Jan 1995, Volume: 31, Issue: 1, On page (s): 169-171

  In the near future semiconductor manufacturing process and the like, it is expected that a laser beam having a shorter wavelength will be required.

However, since materials such as BBO (BaB ₂ O ₄ ) and CLBO (CsLiB ₆ O ₁₀ ) have a long fundamental absorption edge, it is difficult to generate laser light of 180 nm or less. Also, KBBF (KBe ₂ BO ₃ F ₂ ) is not practical due to its strong toxicity. Even if CBO is used, as described above, 185 nm is the limit of shortening the wavelength in the prior art. Thus, in the realization of a laser light source having a wavelength of 180 nm or less, there is a problem that an appropriate material has not been found.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a laser light generation apparatus and a laser light generation method that generate laser light having a short wavelength of 180 nm or less with high efficiency, stability, and long life.

In order to achieve the above object, a laser beam generator according to the present invention comprises:
First laser light irradiation means for irradiating the first laser light;
Second laser light irradiation means for irradiating the second laser light;
A laser beam generator comprising: a third laser beam generating means for generating a third laser beam by mixing the first laser beam and the second laser beam with a sum frequency;
A wavelength of the first laser beam is in a range of 190 to 200 nm;
A wavelength of the second laser light is in a range of 1540 to 1565 nm;
The third laser light generating means includes a CBO crystal, and the sum frequency mixing is performed by irradiating the CBO crystal with the first laser light and the second laser light; and
The wavelength of the third laser light is in a range of 170 to 178 nm.

Further, the laser beam generation method of the present invention includes
A first laser beam generating step for generating a first laser beam;
A second laser beam generating step for generating a second laser beam;
A third laser beam generation step of generating a third laser beam by mixing the first laser beam and the second laser beam in a sum frequency,
A wavelength of the first laser beam is in a range of 190 to 200 nm;
A wavelength of the second laser light is in a range of 1540 to 1565 nm;
Irradiating the CBO crystal with the first laser light and the second laser light in the third laser light generating step, performing the sum frequency mixing with the CBO crystal; and
The wavelength of the third laser light is in a range of 170 to 178 nm.

As described above, 185 nm is the limit for shortening the wavelength even when a CBO (CsB ₃ O ₅ ) crystal, which is expected to generate a short wavelength laser beam, is used. However, as a result of earnest research, the present inventors have made the sum frequency mixing of the first laser light with a wavelength of 190 to 200 nm and the second laser light with a wavelength of 1540 to 1565 nm by a CBO (CsB ₃ O ₅ ) crystal. Thus, the inventors have found that a short wavelength laser beam having a wavelength of 170 to 178 nm can be obtained, and reached the present invention.

  The laser beam generator and laser beam generation method of the present invention can generate a laser beam having a short wavelength of 170 to 178 nm with high efficiency, stability, and long life by having the above-described configuration. According to the present invention, for example, in semiconductor manufacturing, wafer inspection, and mask inspection, inspection that could not be realized in the past can be performed, and a great influence on the semiconductor industry is expected. For example, by applying the present invention to a semiconductor manufacturing process and a mask manufacturing process, it is possible to improve inspection accuracy, improve yield, reduce manufacturing cost, and the like.

  Hereinafter, embodiments of the present invention will be described.

The laser beam generator of the present invention is as described above.
First laser light irradiation means for irradiating the first laser light;
Second laser light irradiation means for irradiating the second laser light;
A laser beam generator comprising: a third laser beam generating means for generating a third laser beam by mixing the first laser beam and the second laser beam with a sum frequency;
A wavelength of the first laser beam is in a range of 190 to 200 nm;
A wavelength of the second laser light is in a range of 1540 to 1565 nm;
The third laser light generating means includes a CBO crystal, and the sum frequency mixing is performed by irradiating the CBO crystal with the first laser light and the second laser light; and
The wavelength of the third laser light is in a range of 170 to 178 nm.

  The schematic diagram of FIG. 1 shows an outline of the laser beam generator of the present invention. As shown in the figure, the laser beam generator 1 includes a first laser beam irradiation unit 100, a second laser beam irradiation unit 200, and a third laser beam generation unit 300. The third laser light generating means 300 includes a CBO crystal. When the CBO crystal in the third laser light generating means 300 is irradiated with the first laser light 101 and the second laser light 201, a sum frequency mixing of the first laser light and the second laser light is performed by the CBO crystal. Three laser beams 301 are generated.

  Other than these, the laser beam generator of the present invention is not particularly limited. For example, the positional relationship and the coupling relationship of the first laser light irradiation means, the second laser light irradiation means, and the third laser light generation means are not particularly limited, and the first laser light and the first laser light are added to the CBO crystal. It is only necessary that the sum frequency mixing can be performed by irradiating two laser beams. In order to perform the sum frequency mixing, the wavelengths of the first laser beam and the second laser beam may be as described above. For example, the incident angles of the first laser beam and the second laser beam on the CBO crystal are not particularly limited and can be set as appropriate. Further, the first laser light irradiation means and the second laser light irradiation means are not particularly limited, and a known laser light source may be used or may be appropriately designed. Furthermore, the laser beam generator of the present invention may or may include components other than the first laser beam irradiation unit, the second laser beam irradiation unit, and the third laser beam generation unit as appropriate. It does not have to be. For example, the light transmitted through the CBO crystal may include residual first laser light and second laser light (not shown) in addition to the third laser light 301. In such a case, for example, the third laser beam 301 may be separated from the other light by an appropriate separating unit, and only the third laser beam 301 may be used. In addition to such a case, in the present invention, when the light is mixed light having a plurality of wavelengths, the mixed light may be separated for each wavelength as necessary. The separation means is not particularly limited, and examples thereof include a wavelength selective reflection mirror, a wavelength dispersion prism, and a diffraction grating. Although it does not restrict | limit especially as a wavelength selective reflection mirror, For example, a dielectric multilayer mirror etc. are mentioned. Further, the wavelength selective reflection mirror may be used, for example, to align the incident directions of a plurality of incident lights having different wavelengths as described later.

The laser beam generation method of the present invention is as described above.
A first laser beam generating step for generating a first laser beam;
A second laser beam generating step for generating a second laser beam;
A third laser beam generation step of generating a third laser beam by mixing the first laser beam and the second laser beam in a sum frequency,
A wavelength of the first laser beam is in a range of 190 to 200 nm;
A wavelength of the second laser light is in a range of 1540 to 1565 nm;
Irradiating the CBO crystal with the first laser light and the second laser light in the third laser light generating step, performing the sum frequency mixing with the CBO crystal; and
The wavelength of the third laser light is in a range of 170 to 178 nm.
Other than these, the laser light generation method of the present invention is not particularly limited. For example, the laser beam generation method of the present invention may or may include steps other than the first laser beam generation step, the second laser beam generation step, and the third laser beam generation step as appropriate. It is not necessary. The laser light generation method of the present invention may be implemented by any apparatus, but is preferably performed by the laser light generation apparatus of the present invention.

  In the laser beam generator and laser beam generation method of the present invention, the first laser beam and the second laser beam are not particularly limited, and may be a continuous wave or a pulse wave (pulse laser beam), respectively. When the first laser beam and the second laser beam are pulsed laser beams, it is necessary that the timings of the pulses of the first laser beam and the second laser beam are synchronized. From the viewpoint of improving the efficiency of sum frequency mixing by the CBO crystal, it is preferable that the timing synchronization of the pulses is as close as possible. Further, when the first laser light and the second laser light are pulsed laser lights, when these lights are irradiated so as to be spatially overlapped (overlapped) in the CBO crystal, the light pulse is high. Sum frequency mixing can be performed more efficiently using the peak power. Similarly, even when the first laser light and the second laser light are continuous waves, it is more efficient to irradiate these lights so that they are spatially overlapped (overlapped) in the CBO crystal. Frequency mixing can be performed. The wavelength of the third laser beam that can be generated according to the present invention is 170 to 178 nm as described above. The wavelength of the third laser light is preferably 170 to 177 nm, and the shorter the wavelength, the better, for example, 175 nm. In this way, short-wavelength light in particular among ultraviolet light is sometimes referred to as “vacuum ultraviolet light”. In addition, vacuum ultraviolet light and laser light are sometimes referred to as “vacuum ultraviolet laser light”. However, these definitions do not limit or limit the present invention. For example, “vacuum ultraviolet light” was named because it was difficult in the prior art to penetrate the atmosphere. However, in practice, vacuum ultraviolet light can be transmitted through the atmosphere to some extent, and in the vacuum ultraviolet light of the present invention, the transmittance in the atmosphere is not limited or limited. In the present invention, the wavelength of vacuum ultraviolet light is not particularly limited. In the present invention, “the pulse timing is synchronized” with respect to two or more laser beams means that the period and phase of the two or more laser beam pulses are appropriate for performing sum frequency mixing or the like. It means being synchronized.

[1: First laser beam irradiation means]
In the present invention, the first laser light irradiation means is not particularly limited, but is as follows, for example.

  The first laser light irradiation means may include, for example, an external resonator, and the first laser light may be light that has undergone resonance by the external resonator. Further, the first laser light irradiation means may include, for example, an optical parametric oscillator, and the first laser light may be light that has undergone resonance by the optical parametric oscillator. Further, the first laser light irradiation means may include, for example, an internal resonator, and the first laser light may be light that has undergone resonance by the internal resonator. Use of resonance by these external resonators, optical parametric oscillators, or internal resonators is preferable from the viewpoints of generation efficiency, reliability, device life, etc. of the first laser light. Further, as described above, the first laser light may be a continuous wave or a pulse wave.

The first laser beam irradiation means includes, for example, a CLBO (CsLiB ₆ O ₁₀ ) crystal, and the generation efficiency of the first laser beam is that the first laser beam is a laser beam generated from the CLBO crystal. From the viewpoints of reliability, device life and the like. In this case, the wavelength of the first laser beam is not particularly limited, but is preferably in the range of 193 to 199 nm. The form of the CLBO crystal is not particularly limited, but is preferably a single crystal. The CLBO crystal may be used as a sum frequency mixing means described later, or may be used as another means.

  Further, the first laser light irradiation means includes, for example, a first (A) laser light generation means, a first (B) laser light generation means, the first (A) laser light, and a first (B) laser. Sum frequency mixing means for obtaining the first laser beam by mixing the two sum frequencies of light may be included. The wavelength of the first (A) laser beam is not particularly limited, but is, for example, 235 to 270 nm, preferably 240 to 250 nm, and particularly preferably 244 nm. The wavelength of the first (B) laser beam is not particularly limited, but is, for example, 1030 to 1080 nm, preferably 1045 to 1070 nm, and particularly preferably 1064 nm. In this case, the wavelength of the first laser beam is not particularly limited. For example, when the wavelength of the first (A) laser beam is 244 nm and the wavelength of the first (B) laser beam is 1064 nm, the wavelength of the first laser beam is 198 to 199 nm (for example, 198.5 nm). It may be. Each of the first (A) laser beam and the second laser beam (B) may be a continuous wave or a pulse wave (pulse laser beam). When the first (A) laser beam and the second laser beam (B) are pulse laser beams, the timings of the pulses of the first (A) laser beam and the second laser beam (B) are as close as possible to each other. Synchronizing with timing is preferable from the viewpoint of improving the efficiency of sum frequency mixing.

  Hereinafter, each of the first (A) laser light generation means, the first (B) laser light generation means, and the sum frequency mixing means will be described.

[1-1. First (A) Laser Light Generation Means]
The first (A) laser beam generating means is not particularly limited, but is as follows, for example.

That is, the first (A) laser beam generating means used in the present invention is, for example, a laser beam generator,
Fundamental wave generating means for generating a fundamental wave;
First second harmonic generation means;
An optical parametric oscillator,
Second second harmonic generation means;
A third second harmonic generation means,
The fundamental wave is converted to a second harmonic by the first second harmonic generation means,
The second harmonic generated from the first second harmonic generation means is resonated by the optical parametric oscillator (the optical parametric oscillator is excited by the second harmonic generated from the first second harmonic generation means. And)
The resonated light is converted into a second harmonic by the second second harmonic generation means,
The second harmonic generated from the second second harmonic generation means is further converted into the second harmonic by the third second harmonic generation means to be the first (A) laser beam,
A laser beam generator may be used.

  The fundamental wave may be a continuous wave or a pulse wave (pulse laser beam). When the first (A) laser beam generating means has the above-described configuration, the fundamental wave is preferably a pulse wave, for example. The wavelength of the fundamental wave is not particularly limited, but is, for example, 1030 to 1080 nm, preferably 1045 to 1070 nm, and particularly preferably 1064 nm. The wavelength of the second harmonic generated from the first second harmonic generating means is not particularly limited, but is a half of the wavelength of the fundamental wave, for example, 515 to 540 nm, preferably 522 to 535 nm, Particularly preferred is 532 nm. The wavelength of the light resonated by the optical parametric oscillator is not particularly limited, but is, for example, 940 to 1080 nm, preferably 960 to 1000 nm, and particularly preferably 976 nm. The wavelength of the second harmonic generated from the second second harmonic generation means is not particularly limited, but is a half of the wavelength of light resonated by the optical parametric oscillator, for example, 470 to 540 nm. , Preferably 480 to 500 nm, particularly preferably 488 nm. The second harmonic generated from the third second harmonic generation means, that is, the wavelength of the first (A) laser light is not particularly limited, but the second harmonic generated from the second second harmonic generation means. One half of the wavelength of the second harmonic, for example, 235 to 270 nm, preferably 240 to 250 nm, particularly preferably 244 nm.

The fundamental wave generating means is not particularly limited, but for example, YDFA (Yterbium Doped Fiber Amplifier), Nd: YAG laser light source, Nd: YVO ₄ laser light source, Nd: YLF laser light source, Yb: YAG laser A light source or the like may be used. In this case, the wavelength of the fundamental wave is, for example, 1064 nm, but may not be strictly 1064 nm but may be an appropriate wavelength as described above, for example. The first to third second harmonic generation means are not particularly limited. For example, each of the first to third second harmonic generation means may include an appropriate NLO (nonlinear optical crystal) and perform conversion to the second harmonic by the NLO. Examples of the NLO include LBO (LiB ₃ O ₅ ) crystal, β-BBO crystal, CLBO crystal, SBBO (Sr ₂ Be ₂ B ₂ O ₇ ) crystal, LN crystal (LiNbO ₃ ), and KTP crystal (KTiOPO ₄ ). And periodic polarization-reversed LN, LT, KTP (PPLN, PPLT, PPKTP) and the like. In the first second harmonic generation means, the NLO is preferably an LBO crystal, or KTP, PPLN, PPLT, or PPKTP from the viewpoint of the generation efficiency of the second harmonic. In the second second harmonic generation means, the NLO is preferably an LBO crystal, or PPLN, PPLT, or PPKTP from the viewpoint of the generation efficiency of the second harmonic. In the third second harmonic generation means, the NLO is preferably a β-BBO crystal or a CLBO crystal from the viewpoint of the second harmonic generation efficiency and the like. The crystal form of the NLO is not particularly limited, and may be, for example, type I or type II. In the present invention, the optical parametric oscillator (OPO) is not particularly limited. For example, the optical parametric oscillator (OPO) may include an appropriate NLO (nonlinear optical crystal) and perform optical parametric oscillation using the NLO. Examples of the NLO include a KTP (KTiOPO ₄ ) crystal, a PPLN (Periodically Polinated Lithium Niobate) crystal, a PPLT (Periodically Poled Lithium Tantalate) Lithium Tantalumate (O ₃₎ ) Crystal, KTA (KTiOAsO ₄ ), RTP (RbTiOAsO ₄ ) and the like.

  Position of each component of the fundamental wave generating means, the first second harmonic generating means, the second second harmonic generating means, the third second harmonic generating means, and the optical parametric oscillator The relationship, the coupling relationship, and the like are not particularly limited as long as the operations such as wavelength conversion and optical parametric oscillation described above are possible. Further, for example, two of the second second harmonic generation means and the third second harmonic generation means are replaced with one, or three or more appropriate harmonic generation means. It may be used to obtain an appropriate wavelength. Further, the first (A) laser beam generating means may or may not contain other components as appropriate.

Further, the first (A) laser light generating means is, for example,
Excitation light generating means for generating excitation light;
VECSEL (external cavity surface emitting laser);
One or more harmonic generation means,
Resonating the excitation light directly with the VECSEL,
The laser light generator may convert the resonated light into a harmonic by the harmonic generation means and use the first (A) laser light. The excitation light may be a continuous wave or a pulse wave, but for example, a continuous wave is preferable. The wavelength of the excitation light is not particularly limited, but is, for example, 780 to 830 nm, preferably 800 to 820 nm, and more preferably 805 to 815 nm. The excitation light generating means is not particularly limited, and examples thereof include a high-power lateral multimode semiconductor laser and a semiconductor laser array. The form of the VECSEL is not particularly limited. For example, the form may include a VECSEL chip and a VECSEL resonator. The VECSEL chip is not particularly limited, and examples thereof include an InGaAs quantum well. The harmonic generation means is not particularly limited. For example, it may be the same as the second second harmonic generation means and the third second harmonic generation means. That is, the resonated light is converted into a second harmonic by the second second harmonic generation means, and a second harmonic generated from the second second harmonic generation means is further converted into the second harmonic. 3 may be converted into the second harmonic by the second harmonic generation means to obtain the first (A) laser beam.

[1-2. First (B) Laser Light Generation Means]
Next, the first (B) laser light generating means is not particularly limited, but for example, YDFA (Yterbium Doped Fiber Amplifier), Nd: YAG laser light source, Nd: YVO ₄ laser light source, Nd: A YLF laser light source, a Yb: YAG laser light source, or the like may be used. In this case, the wavelength of the first (B) laser beam is, for example, 1064 nm, but may not be strictly 1064 nm, but may be an appropriate wavelength as described above, for example.

  The first (B) laser light generating means may be separate from the first (A) laser light generating means. Further, for example, the fundamental wave generating means in the first (A) laser light generating means also serves as the first (B) laser light generating means, and the fundamental wave also serves as the first (B) laser light. May be. In this case, the first laser light irradiation means of the present invention includes the first (A) laser light generation means, the first (B) laser light generation means, the first (A) laser light, and the first (B) In addition to the means (sum frequency mixing means) for obtaining the first laser light by the two sum frequency mixing of the laser light, it is preferable to further include a fundamental wave separation means. For example, the light generated from the first second harmonic generation means in the first (A) laser light irradiation means is separated into a second harmonic and a fundamental wave by the fundamental wave separation means. The separated fundamental wave is used as the first (B) laser beam. The first (B) laser light and the first (A) laser light, which is the second harmonic generated from the third second harmonic generation means, are sum frequency mixed by the sum frequency mixing means. To generate laser light.

[1-3. Sum frequency mixing means]
The means (sum frequency mixing means) for obtaining the first laser light by mixing two sum frequencies of the first (A) laser light and the first (B) laser light is not particularly limited. For example, the sum frequency mixing means may include an appropriate NLO (nonlinear optical crystal) and perform sum frequency mixing by the NLO. Examples of the NLO include LBO (LiB ₃ O ₅ ) crystals, β-BBO (BaB ₂ O ₄ ) crystals, and CLBO crystals. Among these, a β-BBO crystal and a CLBO crystal are preferable from the viewpoints of the generation efficiency and reliability of the first laser beam, the device lifetime, and the like. The crystal form of the NLO is not particularly limited, and may be, for example, type I or type II.

  In the schematic diagram of FIG. 2, the first (A) laser light generating means, the first (B) laser light generating means, the first (A) laser light, and the first (B) laser light An example of the 1st laser beam irradiation means containing the means (sum frequency mixing means) which obtains the 1st laser beam by sum frequency mixing is shown. As shown in the figure, the first laser light irradiation means includes a first (A) laser light irradiation means 160, a first (B) laser light generation means 102, and a sum frequency mixing means 150 as main components. The first (B) laser light generation means 102 also serves as the fundamental wave generation means in the first (A) laser light irradiation means 160. The first (A) laser light irradiation means 160 includes a fundamental wave generation means 102, a first second harmonic generation means 110, an optical parametric oscillator (OPO) 140, a second second harmonic generation means 120, and a first The third harmonic generation means 130 of No. 3 is a main component. The positional relationship, coupling relationship, etc. of these components are not particularly limited as long as each step in the first laser beam irradiation described later can be performed. For example, the optical parametric oscillator (OPO) 140 and the second second harmonic generation means 120 are arranged in one resonator having the reflection mirror 4000 as a main component, and an OPO signal enhanced in the resonator. The second harmonic may be efficiently generated by using light.

  The first laser light irradiation using the first laser light irradiation means can be performed as follows, for example. Hereinafter, a description will be given with reference to FIG. Note that the wavelengths shown in the following description and drawings are examples for convenience of explanation, and are not limited to these wavelengths unless departing from the scope of the present invention.

  That is, first, as shown in the figure, the fundamental wave 103 (1064 nm) is generated by the fundamental wave generating means 102. This fundamental wave is converted into a first second harmonic 111 (532 nm) by the first second harmonic generation means 110. The first second harmonic generation means 110 generates an unconverted fundamental wave 103 in addition to the first second harmonic 111. These are separated into a first second harmonic 111 and an unconverted fundamental wave 103 by fundamental wave separation means (not shown). The fundamental wave separation means is not particularly limited, and examples thereof include a wavelength selective reflection mirror as described above. Examples of the wavelength selective reflection mirror include a dielectric multilayer mirror. The unconverted fundamental wave 103 (1064 nm) is used as the first (B) laser beam. On the other hand, the first second harmonic 111 is irradiated to the optical parametric oscillator (OPO) 140 to cause excitation, and the light 141 (976 nm) resonated by the resonance by the optical parametric oscillator (OPO) 140 is generated. The resonated light 141 (976 nm) is converted into a second second harmonic 121 (488 nm) by the second second harmonic generation means 120. At this time, for example, the optical parametric oscillator (OPO) 140 and the second second harmonic generation means 120 may be disposed in the same resonator having the reflecting mirror 4000 as a main component. Next, the second second harmonic 121 (488 nm) is converted into the third second harmonic 131 (244 nm) by the third second harmonic generation means 130. Then, the third second harmonic 131, that is, the first (A) laser beam (244 nm) is applied to the sum frequency mixing unit 150 together with the unconverted fundamental wave 103, that is, the first (B) laser beam (1064 nm). Then, sum frequency mixing is performed to obtain the first laser beam 101 (198.5 nm).

  For example, the light transmitted through the third second harmonic generation means 130 may include the remaining second second harmonic 121 (not shown). Further, for example, the light transmitted through the sum frequency mixing unit 150 may include the remaining third second harmonic 131 (not shown) and the remaining fundamental wave 103 (not shown). In such a case, the transmitted light may be separated for each wavelength by an appropriate separation means, and only necessary light may be used. Not limited to these cases, as described above, in the present invention, when the light is mixed light of a plurality of wavelengths, the mixed light may be separated for each wavelength as necessary. The separation means is not particularly limited, and is as described above, for example.

[2. Second laser light irradiation means]
Next, the second laser light irradiation means will be described.

  The second laser light irradiation means is not particularly limited. The second laser beam irradiation means may include, for example, an external resonator, and the second laser beam may be light that has undergone resonance by the external resonator. The second laser light irradiation means may include, for example, an optical parametric oscillator, and the second laser light may be light that has undergone resonance by the optical parametric oscillator. The second laser light irradiation means may include, for example, an internal resonator, and the second laser light may be light that has undergone resonance by the internal resonator. Use of resonance by these external resonators, optical parametric oscillators, or internal resonators is preferable from the viewpoints of generation efficiency, reliability, device life, and the like of the second laser light. Further, as described above, the second laser light may be a continuous wave or a pulse wave.

  The second laser light irradiation means may include, for example, an erbium-doped fiber amplifier (EDFA), and the second laser light may be laser light generated from the erbium-doped fiber amplifier.

  The second laser light irradiation means includes, for example, a single-frequency erbium-doped fiber light source that emits laser light having a wavelength of 1540 to 1565 nm and an external resonator, and a laser emitted from the single-frequency erbium-doped fiber light source It is preferable that light is resonated by the external resonator to be the second laser light. In this case, the laser light emitted from the single-frequency erbium-doped fiber light source may be a continuous wave or a pulse wave, but for example, a continuous wave is preferable. In this case, for example, it is more preferable that a CBO crystal is disposed in the external resonator, and the first laser beam and the second laser beam are mixed with each other by the CBO crystal. Thereby, sum frequency mixing can be performed more efficiently. In this case, it is particularly preferable to irradiate the first laser beam so as to overlap with the mode of the external resonator.

The second laser light irradiation means includes, for example, a second (A) laser light generating means for generating a second (A) laser light and an optical parametric oscillator, and the second (A) laser light is converted into the second (A) laser light. The second laser beam may be resonated by an optical parametric oscillator. The second (A) laser light generating means is not particularly limited, and for example, a YDFA (Yterbium Doped Fiber Amplifier) light source, an Nd: YAG laser light source, an Nd: YVO ₄ laser light source, an Nd: YLF laser light source Yb: YAG laser light source or the like may be used. In this case, the wavelength of the second (A) laser light is not particularly limited, but is, for example, 1030 to 1080 nm, preferably 1045 to 1070 nm, and particularly preferably 1064 nm. The optical parametric oscillator (OPO) is not particularly limited. For example, an appropriate NLO (nonlinear optical crystal) may be included, and optical parametric oscillation may be performed by the NLO. Examples of the NLO include a KTP (KTiOPO ₄ ) crystal, a PPLN (Periodically Polinated Lithium Niobate) crystal, a PPLT (Periodically Poled Lithium Tantalate) Lithium Tantalumate (O ₃₎ ) Crystal, KTA (KTiOAsO ₄ ), RTP (RbTiOPO ₄ ) and the like. In this case, the wavelength of the second laser light is not particularly limited as long as it is in the range of 1540 to 1565 nm, but is preferably in the range of 1540 to 1560 nm, and more preferably 1545 to 1555 nm. In addition, when signal light and idler light are present in the light emitted from the optical parametric oscillator, the relationship between the wavelengths of the signal light and the idler light is not particularly limited. As an example, when the wavelength of the second (A) laser light is 1064 nm and the wavelength of the signal light (second laser light) is 1540 to 1560 nm, the wavelength of the idler light may be about 3400 nm, for example. good.

  In the case where both the first laser light irradiation means and the second laser light irradiation means include an optical parametric oscillator, for example, the second laser light is light that has undergone resonance by the optical parametric oscillator, and the first laser light irradiation means The idler light of the optical parametric oscillator included in the one laser light irradiation unit may be resonated by the optical parametric oscillator included in the second laser light irradiation unit. For example, idler light of an optical parametric oscillator included in the first laser light irradiation means may be used as the second (A) laser light.

[3. Third laser light generating means]
In the laser light generating apparatus and laser light generating method of the present invention, the third laser light generating means for sum-frequency mixing the first laser light and the second laser light is not particularly limited except that it includes a CBO crystal. Examples of the third laser light generating means include a ring resonator including a CBO crystal, a standing wave resonator, and a single-pass wavelength conversion device including a wavelength synthesis / separation element.

  In the third laser light generating means, the CBO crystal is not particularly limited, but a single crystal is particularly preferable. The crystal form, size, shape, and the like of the CBO crystal are not particularly limited and can be set as appropriate. Further, the production method of the CBO crystal is not particularly limited, and for example, a known production method can be appropriately used. Note that crystals other than CBO used in the present invention, such as the NLO, are not particularly limited in crystal form, size, shape, etc., and can be set as appropriate.

  Next, an example of the laser beam generation apparatus and the laser beam generation method of the present invention will be described.

  In the present invention, when the first laser light and the second laser light are continuous waves, the third laser light generating means may be, for example, a ring resonator or a standing wave resonator including a CBO crystal. . An example of such a device is shown in FIGS.

  FIG. 3 is a diagram showing an apparatus in which the third laser light generating means 300 is a ring resonator including a CBO crystal in the apparatus of FIG. As shown in the figure, the third laser light generating means (ring resonator) includes a CBO crystal 310 inside an optical resonator having a reflecting mirror 4000 as a main component. The reflecting mirror 4000 can resonate the light inside the third laser light generating means (ring resonator) 300. Other components are the same as those in FIG. 1 and are not particularly limited. The first laser light irradiation means 100 and the second laser light irradiation means are as described above, for example. The second laser light irradiation means 200 may be, for example, a light source including an erbium-doped fiber amplifier (EDFA), a light source including an optical parametric oscillator (OPO), or the like. In addition, in the same figure, a plurality of reflecting mirrors 4000 (mirrors) are shown, but they are not particularly limited and can be appropriately selected and may be the same or different. For example, the mirror on which the second laser beam 201 is incident is an input coupling mirror, and only this mirror has a slightly low reflectance (for example, about 97 to 99%), and other mirrors having higher reflection than that may be used. . By doing so, it is possible to realize wavelength conversion that satisfies optical impedance matching and is more efficient. The same applies to the reflecting mirror 4000 in other drawings.

  The laser light generation method using the apparatus shown in FIG. 3 is particularly effective except that the third laser light 301 generated from the CBO crystal 310 is resonated inside the third laser light generation means (ring resonator) 300 by the reflecting mirror 4000. Without being limited, it can be carried out according to the laser beam generation method of the present invention.

  The apparatus of FIG. 4 is the same as that of FIG. 3 except that the third laser light generating means 300 is a standing wave resonator including a CBO crystal. In the laser beam generation method using this apparatus, the third laser beam 301 generated from the CBO crystal 310 is amplified (resonated) inside the third laser beam generating means (standing wave resonator) 300 by the reflecting mirror 4000. Other than the above, there is no particular limitation, and it can be carried out according to the laser beam generation method of the present invention.

  In the present embodiment, the case where the first laser beam and the second laser beam are continuous waves has been described. However, even when the first laser beam and the second laser beam are pulse waves, the third laser beam generator is a ring resonator or a standing wave resonator including a CBO crystal, as in the present embodiment. May be.

  Next, another example of the laser beam generation apparatus and the laser beam generation method of the present invention will be described.

  As described above, the second laser light irradiation means includes a second (A) laser light generation means for generating a second (A) laser light and an optical parametric oscillator, and the second (A) laser light is supplied to the second laser light irradiation means. The second laser beam may be resonated by an optical parametric oscillator. In this case, the optical parametric oscillator and the CBO crystal in the third laser light generating means may be disposed in the same resonator. Examples of the form of this resonator include a ring resonator and a standing wave resonator. The second (A) laser beam generating means and the optical parametric oscillator are not particularly limited, but are as described above, for example. In this case, the second laser light may be a continuous wave or a pulse wave, but is preferably a continuous wave. In this case, the first laser beam may be a continuous wave or a pulse wave, but is preferably a continuous wave.

  FIG. 5 shows an example of such a laser beam generator. As shown in the figure, this apparatus mainly includes a first laser light irradiation means 100, a second laser light irradiation means 200, and a third laser light generation means 300. The second laser light irradiation means includes a second (A) laser light generation means 102 ″ and an optical parametric oscillator (OPO) 180 as main components. The second (A) laser light generation means 102 ″ is not particularly limited, and examples thereof include a YDFA light source and an Nd: YAG laser light source as described above. The optical parametric oscillator (OPO) 180 is not particularly limited and is as described above. For example, PPLN is preferable. The third laser light generating means 300 is composed of a CBO crystal 310. The CBO crystal 310 and the OPO 180 are arranged in a ring resonator (ring OPO resonator) 4100. The ring resonator 4100 has a reflecting mirror 4000 as a main component, and causes the light to resonate inside by the reflecting mirror 4000. The positional relationship and the coupling relationship of the constituent elements are not particularly limited as long as the laser light generation method described below can be performed.

  The laser beam generation method using the apparatus of FIG. 5 can be performed as follows, for example. That is, first, the first laser light 101 (190 to 200 nm) is generated from the first laser light source 100. The first laser beam 101 is irradiated to the CBO crystal 310 in the ring resonator 4100. On the other hand, a second (A) laser beam 103 ″ (for example, 1064 nm) is generated from the second (A) laser beam generating means 102 ″ (YDFA light source or the like), and irradiated to the OPO 180 in the ring resonator 4100. Thereby, the OPO 180 is excited and the second laser beam is generated. The second laser light is resonated by the reflecting mirror 4000 constituting the ring resonator 4100 and is irradiated to the CBO crystal 310. Then, the first laser light 101 and the second laser light irradiated on the CBO crystal 310 (third laser light generating means 300) are sum-frequency mixed by the CBO crystal 310, and the third laser light 301 is generated.

  Next, still another example of the laser beam generation apparatus and the laser beam generation method of the present invention will be described.

  When the first laser light and the second laser light are pulse waves, the third laser light generation means may be configured such that, for example, the CBO crystal is not stored in a resonator, and the CBO crystal has the first laser light. A laser beam and the second laser beam may be directly irradiated. The first laser beam and the second laser beam may be sum-frequency mixed by a so-called single pass.

  FIG. 6 shows an example of such a device. The figure shows an example in which the third laser light generating means 300 is formed from a CBO crystal 310 and the CBO crystal 310 is not stored in the resonator. Except for this, the apparatus of the figure is not particularly limited and is the same as that of FIG. For example, the CBO crystal 310 may be stored in an appropriate container to form the third laser light generating means 300.

  The laser light generation method using the apparatus of FIG. 6 is not particularly limited, and can be appropriately performed according to the laser light generation method of the present invention. In the figure, the case where the light transmitted through the CBO crystal 310 includes the remaining first laser light 101 and second laser light 201 in addition to the third laser light 301 is shown. In this case, as described above, only the third laser beam 301 may be used by separating the third laser beam 301 and the other light by a wavelength selective mirror or the like.

  As described above, for example, when the CBO crystal is a Brewster cut crystal, an appropriate incident angle varies depending on the wavelength. For this reason, it is preferable to set the laser beam generator of the present invention so that the CBO crystal is irradiated with the first laser beam and the second laser beam at an appropriate incident angle and is efficiently sum-frequency mixed.

  Further, for example, when the first laser beam and the second laser beam are perpendicularly incident (irradiated) on the CBO crystal, the first laser beam and the second laser beam are emitted using a dielectric multilayer mirror. It may be incident after being superimposed (irradiated). FIG. 7 shows an example of such a device. As shown in the figure, this apparatus includes two wavelength-selective reflecting mirrors 5000 and 5000 ′, and the incident directions of the first laser beam 101 and the second laser beam 201 are perpendicular to the CBO crystal 310. This is the same as the apparatus shown in FIG. The positional relationship, coupling relationship, and the like of each component are not particularly limited as long as the laser light generation method described below can be performed.

  The laser beam generation method using this apparatus can be performed as follows, for example. That is, first, the first laser light 101 is generated from the first laser light irradiation means 100. Then, the first laser beam 101 is applied to one surface of the wavelength selective reflection mirror 5000 from a direction inclined with respect to the surface. The first laser beam 101 is reflected by the surface of the wavelength selective reflection mirror 5000. On the other hand, the second laser light 201 is generated from the second laser light irradiation means 200. Then, the second laser beam 201 is applied to the other surface of the wavelength selective reflection mirror 5000 from a direction inclined with respect to the surface. The second laser beam 201 passes through the wavelength selective mirror 5000, is superimposed on the first laser beam 101, and travels in the same direction as the first laser beam 101. The superimposed first laser beam 101 and second laser beam 201 are irradiated perpendicularly to the CBO crystal 310. The first laser light 101 and the second laser light 201 are sum-frequency mixed by the CBO crystal 310 to become the third laser light 301. The light transmitted through the CBO crystal 310 includes the remaining first laser light 101 and second laser light 201 in addition to the third laser light 301. The transmitted light is irradiated on one surface of the wavelength selective reflection mirror 5000 'from a direction inclined with respect to the surface. The first laser beam 101 and the second laser beam 201 are reflected by the wavelength selective reflection mirror 5000 ', and only the third laser beam 301 is transmitted through the wavelength selective reflection mirror 5000'. As a result, the third laser beam 301 can be separated from the other light, and only the third laser beam 301 can be used.

  Next, still another example of the laser beam generation apparatus and the laser beam generation method of the present invention will be described.

  FIG. 8 schematically shows the laser beam generator of this embodiment. As shown in the figure, this laser light generation apparatus includes a first laser light irradiation unit 100, a second laser light irradiation unit 200, and a third laser light generation unit 300 as main components. The third laser light generating means 300 includes a CBO crystal.

  The first laser light irradiation means 100 includes a first (A) laser light generation means 160, a first (B) laser light generation means 102 ', and a sum frequency mixing means 150 as main components. The first (A) laser light generation means 160 includes the excitation light generation means 102 ′ ″, the VECSEL 170, the second second harmonic generation means 120, and the third second harmonic generation means 130 as main components. . That is, the first (A) laser light generation means 160 includes a VECSEL 170 instead of the first second harmonic generation means 110 and the optical parametric oscillator 140. The VECSEL 170 oscillates with laser light having a wavelength of 940 to 1080 nm, for example, and has a function equivalent to that of the optical parametric oscillator in the above-described embodiment. The configuration of the VECSEL is not particularly limited, but is as described above, for example, and may be a configuration including a VECSEL chip and a VECSEL resonator. The excitation light generation means 102 ″ ″ is not particularly limited, but is as described above, for example. Except for these, the first (A) laser beam generating means 160 shown in FIG. 8 is the same as FIG.

  In the present invention, harmonic generation means and sum frequency mixing means (for example, second second harmonic generation means 120, third second harmonic generation means 130, and sum frequency mixing means 150 in FIG. 6). The form is not particularly limited. For example, the ring resonator or the standing wave resonator having the structure shown in FIG. 3 or 4 may be used, and an appropriate NLO or the like may be included instead of the CBO crystal. The NLO is not particularly limited and may be appropriately selected according to the wavelength or the like. Specific examples of the NLO are not particularly limited, and examples thereof include the above-described various NLOs.

  Next, the second laser light irradiation means 200 includes the second (A) laser light generation means 102 ″ and the optical parametric oscillator 180 as main components.

The first (B) laser light generating means 102 ′ and the second (A) laser light generating means 102 ″ are not particularly limited. For example, a YDFA (Yterbium Doped Fiber Amplifier) light source, Nd: YAG A laser light source, an Nd: YVO ₄ laser light source, an Nd: YLF laser light source, a Yb: YAG laser light source, or the like may be used. These may use separate light sources, but may use the same light source.

  In FIG. 8, each component is not particularly limited. For example, it is the same as in FIGS. 1 and 2, and is as described above. The positional relationship, the coupling relationship, etc. of the constituent elements are not particularly limited as long as each step in the laser beam generation method described later can be performed. Further, the wavelengths of the first laser beam 101, the second laser beam 201, and the third laser beam 301 are not particularly limited as long as they do not deviate from the scope of the present invention. The wavelength of the excitation light 103 ″ ″ is not particularly limited, but is as described above, for example. The wavelengths of the first (B) laser beam 103 ′ and the second (A) laser 103 ″ are not particularly limited, but are as described above, for example. The wavelength of the light 171 oscillated by VECSEL is not particularly limited, but is, for example, 940 to 1080 nm, preferably 960 to 1000 nm, and more preferably 974 to 978 nm. The wavelength of the second second harmonic 121 is not particularly limited, but is half the wavelength of the light 171, for example, 470 to 540 nm, preferably 480 to 500 nm, and more preferably 487 to 489 nm. The wavelength of the third second harmonic 131 is not particularly limited, but is half the wavelength of the second second harmonic 121, for example, 235 to 270 nm, preferably 240 to 250 nm, more preferably 243.5 to 244.5 nm.

  The laser beam generation method using the apparatus of FIG. 8 can be performed as follows, for example. In the following description and the description in FIG. 8, the forming material of each component and the wavelength of light are examples for convenience of description, and are not limited thereto.

  That is, first, excitation light 103 ″ ″ (810 nm) is generated from excitation light generation means 102 ″ ″ (excitation light source). The fundamental wave 103 is resonated by the VECSEL 170 to obtain a resonated light 171 (976 nm). The light 171 is converted into the second second harmonic 121 (488 nm) by the second second harmonic generation means 120 (including the LBO crystal). Further, the second second harmonic 121 (488 nm) is converted into the third second harmonic 131, that is, the first (A) laser beam (including the CLBO crystal) by the third second harmonic generating means 131 (including the CLBO crystal). 244 nm).

  On the other hand, the first (B) laser beam 103 '(1064 nm) is generated from the first (B) laser beam generator 102' (YDFA light source). Then, the third second harmonic 131, that is, the first (A) laser beam (244 nm) is applied to the sum frequency mixing means 150 together with the first (B) laser beam 103 ′ (1064 nm) to perform sum frequency mixing. The first laser beam 101 (198 to 199 nm, for example 198.5 nm).

  Further, the second (A) laser beam generating means 102 ″ (YDFA light source) generates the second (A) laser beam 103 ″ (1064 nm). The second (A) laser beam 103 ″ (1064 nm) is irradiated and excited by irradiating the optical parametric oscillator 180 (including PPLN) to generate second laser light 201 (1540 nm) by oscillation. Then, the first laser beam 101 (198 to 199 nm, for example, 198.5 nm) and the second laser beam 201 (1540 to 1565 nm) are irradiated to the third laser beam generating means 300 including the CBO crystal, and the CBO crystal is irradiated. To make the third laser light 301 (170 to 178 nm, for example, 175 nm). In this way, the laser beam generation method using the apparatus of FIG. 8 can be performed.

  In the case of FIG. 8, each light may be continuous wave or pulsed light. Further, for example, the first laser beam 101 is a continuous wave, and the optical parametric oscillator 180 and the third laser beam generating means 300 including the CBO crystal are stored in the same container, and the first laser beam 101 is stored by this CBO crystal. It is more preferable to perform sum frequency mixing of the laser beam 201 and the second laser beam 201. According to this configuration, since the intensity of the second laser light 201 applied to the CBO crystal is increased, the sum frequency mixing can be performed more efficiently. In this case, the container in which the optical parametric oscillator 180 and the third laser light generating means 300 including the CBO crystal are stored is, for example, in the form of a ring resonator (ring OPO resonator) as shown in FIG. You may have taken.

  Further, for example, the second (A) laser light irradiation means 102 ″ may be replaced with a single frequency erbium-doped fiber light source, and an external resonator may be used instead of the OPO 180 as a resonator. In this case, it is preferable that a CBO crystal is disposed in the external resonator, the external resonator is locked to an EDFA light source, and the output light resonates to become the second laser light 201. Thereby, the sum frequency mixing of the first laser beam 101 and the second laser beam 201 using the CBO crystal can be performed more efficiently. In this case, it is particularly preferable to irradiate the first laser beam so as to overlap with the mode of the external resonator. For example, the intensity of the second laser beam 201 is increased by locking the external resonator to an integral multiple of the EDFA output wavelength to increase the power in the resonator, and the sum of the first laser beam 101 and the second laser beam 201 is increased. The frequency mixing efficiency can also be increased.

  Further, for example, the first (A) laser light generation means 160 is configured to obtain laser light having a wavelength of about 244 nm by the second high frequency of the Ar ion laser, instead of the configuration of FIG. 2 or FIG. 8, and the wavelength of about 244 nm. This laser beam may be the first (A) laser beam 131.

  Further, in FIG. 8, the light transmitted through the second second harmonic generation means 120, the third second harmonic generation means 130, the sum frequency mixing means 150, the third laser light generation means 300, etc. It may be mixed light having a plurality of wavelengths including residual incident light. In this case, as described above, the transmitted light may be separated for each wavelength by an appropriate separation unit, and only necessary light may be used.

  Next, still another example of the laser beam generation apparatus and the laser beam generation method of the present invention will be described.

  In the present invention, as a method of synchronizing the first laser beam (190 to 200 nm) and the second laser beam (1540 to 1565 nm), for example, as described in FIGS. 2 and 8, a method using an optical parametric oscillator is used. is there. In addition, for example, a trigger for the modulator may be electrically synchronized. That is, when the first laser light and the second laser light are pulsed laser lights, the second laser light irradiation means includes a continuous wave light source, an optical modulator, and one or a plurality of optical amplifiers. May be. In this case, the continuous wave generated from the continuous wave light source is converted into a pulse wave by the optical modulator, the pulse wave is amplified by the optical amplifier, and the second laser light is converted by the optical modulator and Light that has been amplified by the optical amplifier. For example, in FIG. 8, the second (A) laser light generation means 102 ″ in the second laser light irradiation means 200 is a continuous wave light source, and has an optical modulator and an optical amplifier instead of the optical parametric oscillator 180, The continuous wave 103 ″ may be converted into a pulse wave by the optical modulator and further amplified by the optical amplifier. The continuous wave light source, the optical modulator, and the optical amplifier are not particularly limited. For example, a device having a simple structure in which an optical modulator and a continuous wave light source are fiber-coupled may be used. The optical amplifier may be a fiber amplifier, for example. An example of the fiber amplifier is a rare earth-doped fiber amplifier. Although it does not restrict | limit especially as a rare earth addition fiber amplifier, For example, EDFA etc. are mentioned. That is, for example, a commercially available EDFA light source may be used as the second laser light irradiation unit 200.

  Further, when the first laser light and the second laser light are pulse laser lights, the first laser light irradiation means includes a continuous wave light source, an optical modulator, and one or a plurality of optical amplifiers. May be. In this case, the continuous wave generated from the continuous wave light source is converted into a pulse wave by the optical modulator, the pulse wave is amplified by the optical amplifier, and the first laser light is converted by the optical modulator and Light that has been amplified by the optical amplifier. The continuous wave light source, the optical modulator, and the optical amplifier in the first laser light irradiation means are not particularly limited, and are the same as, for example, the second laser light irradiation means.

In the laser beam generator of the present invention, when the first laser beam and the second laser beam are pulsed laser beams, the first laser beam irradiation unit and the second laser beam irradiation unit are respectively a continuous wave light source. And an optical modulator and one or a plurality of optical amplifiers. In this case, the continuous wave generated from the continuous wave light source is converted into a pulse wave by the optical modulator, the pulse wave is amplified by the optical amplifier, and the first laser light and the second laser light are respectively Light that has undergone conversion by the optical modulator and amplification by the optical amplifier. An example of the configuration of such an apparatus is shown below. The wavelength is an exemplification, and is not limited thereto, and may be any wavelength that does not depart from the scope of the present invention.

(I) a continuous wave laser light source (wavelength: 1550 nm), wherein the continuous wave laser light source includes the continuous wave light source in the first laser light irradiation unit and the continuous wave light source in the second laser light irradiation unit. I also serve.
(Ii) The first laser light irradiation means further includes a harmonic generation means.
(Iii) The first laser light undergoes conversion by the optical modulator and amplification by the optical amplifier (wavelength 1550 nm) in the first laser light irradiation means, and further converted into eighth harmonics by the harmonic generation means Pulsed laser light (wavelength 194 nm).
(Iv) The second laser light is pulsed laser light (wavelength 1550 nm) that has undergone conversion by the optical modulator and amplification by the optical amplifier in the second laser light irradiation means.
(V) The third laser beam is a ninth harmonic (wavelength: about 172 nm) of the second laser beam.

The optical amplifier in the first laser light irradiation means and the optical amplifier in the second laser light irradiation means are not particularly limited, but are as described above. For example, each is preferably a fiber amplifier. The positional relationship, coupling relationship, and the like of each component are not particularly limited as long as the operations shown in (i) to (v) can be performed. As the continuous wave laser light source (wavelength 1550 nm), the first laser light irradiation unit and the second laser light irradiation unit may use one light source, but may use separate light sources. The optical modulator may use separate optical modulators for the first laser light irradiation means and the second laser light irradiation means, but one optical modulator may be used as the first laser light irradiation means. The second laser beam irradiating means may also be used. As the optical amplifier, separate optical amplifiers may be used for the first laser light irradiation means and the second laser light irradiation means, respectively, but one optical amplifier is used as the first laser light irradiation means and the second laser light irradiation means. You may also use with a laser beam irradiation means. The harmonic generation means and the method for obtaining the eighth harmonic thereby are not particularly limited. For example, the harmonic generation means may be composed of three second harmonic generation means, and each of the second harmonic means may be used once to obtain the eighth harmonic. In order to obtain the ninth harmonic, that is, the third laser beam, the first laser beam (eighth harmonic) and the second laser beam (fundamental wave) are obtained using a CBO crystal according to the present invention. Mix sum frequency.

FIG. 9 schematically shows an example of such an apparatus. As shown in the figure, this apparatus mainly includes a first laser light irradiation means 100, a second laser light irradiation means 200, and a third laser light generation means 300. The first laser light irradiation means 100 includes a continuous wave light source 104, an optical modulator 106, an optical amplifier 108, a first second harmonic generation means 110, a separation means (not shown), a second The second harmonic generation means 120 and the third second harmonic generation means 130 are main components. The continuous wave light source 104, the optical modulator 106, the optical amplifier 108, the first second harmonic generation means 110, and the separation means (not shown) also serve as components of the second laser light irradiation means 200. The second laser beam irradiation means 200 has these as main components. The third laser light generating means 300 includes a CBO crystal. The continuous wave light source 104, the optical modulator 106, and the optical amplifier 108 are not particularly limited, but are as described above, for example. The first second harmonic generation means 110, the second second harmonic generation means 120, and the third second harmonic generation means 130 are not particularly limited. For example, each of the first to third second harmonic generation means may include an appropriate NLO (nonlinear optical crystal) and perform conversion to the second harmonic by the NLO. Examples of the NLO include LBO (LiB ₃ O ₅ ) crystals, β-BBO (BaB ₂ O ₄ ) crystals, CLBO crystals, SBBO (Sr ₂ Be ₂ B ₂ O ₇ ) crystals, and the like. In the first second harmonic generation means 110, as the NLO, for example, LBO crystal or PPLN is preferable from the viewpoint of the generation efficiency of the second harmonic. In the second second harmonic generation means 120, as the NLO, for example, an LBO crystal is preferable from the viewpoint of the generation efficiency of the second harmonic. Further, the third second harmonic generation means 130 may be a combination of a plurality of harmonic generation means, sum frequency mixing means, and the like. The crystal form of the NLO is not particularly limited, and may be, for example, type I or type II. In addition, the positional relationship, coupling relationship, and the like of the respective components in FIG. 9 are not particularly limited as long as a laser beam generation method described below can be performed.

  The laser beam generation method using the apparatus of FIG. 9 can be performed as follows, for example. In the following description and the description in FIG. 9, the wavelength is an example for convenience of description and is not limited thereto. That is, first, a continuous wave 105 (wavelength 1550 nm) is generated from the continuous wave light source 104. The continuous wave 105 is converted into a pulse wave 107 (wavelength 1550 nm) by the optical modulator 106. Further, the pulse wave 107 is amplified by the optical amplifier 108 to obtain a fundamental wave 201 (wavelength 1550 nm). The fundamental wave 201 is converted into the second harmonic 111 (wavelength 775 nm) by the first second harmonic generation means 110. Further, the light transmitted through the first second harmonic generation means 110 is separated into the second harmonic 111 (wavelength 775 nm) and the remaining fundamental wave 201 (wavelength 1550 nm) by the separation means (not shown). To do. This remaining fundamental wave 201 is used as the second laser beam. Further, the second harmonic 111 (wavelength 775 nm) is converted into the fourth harmonic 121 (wavelength 388 nm) by the second second harmonic generation means 120. The fourth harmonic 121 is converted by the third second harmonic generation means 130 into the eighth harmonic, that is, the first laser beam 101 (wavelength 194 nm). Then, the first laser beam 101 (wavelength 194 nm) and the second laser beam 201 (wavelength 1550 nm) are irradiated to the CBO crystal in the third laser beam generating means, and the sum frequency mixing is performed to obtain the ninth harmonic, that is, the third laser. Light 301 (wavelength 172 nm) is generated. As described above, the laser beam generation method using the apparatus of FIG. 9 can be performed.

  The apparatus shown in FIG. 9 can be variously changed. For example, in FIG. 9, the second laser light 201 is separated from the light generated from the first second harmonic generation means 110, but instead of this, the second second harmonic generation means is used. The light generated from 120 or the third second harmonic generation means 130 may be separated and used.

  The harmonic generation means in the first laser light irradiation means 100 is, for example, means for generating the (n + 1) th harmonic by sum frequency mixing of the nth harmonic and the residual fundamental wave (n is an integer of 2 or more). May be included. FIG. 10 schematically shows an example of such an apparatus. As shown in the figure, this apparatus mainly includes a first laser light irradiation means 100, a second laser light irradiation means 200, and a third laser light generation means 300. The first laser light irradiation means 100 includes a continuous wave light source 104, an optical modulator 106, an optical amplifier 108, a second harmonic generation means 110, a third harmonic generation means 1030, a fourth harmonic generation means 1040, and a fifth harmonic. The wave generation means 1050, the sixth harmonic generation means 1060, the seventh harmonic generation means 1070, and the eighth harmonic generation means 1080 are main components. The first laser light irradiation means 100 can also serve as the second laser light irradiation means 200 and can generate both the first laser light 101 and the second laser light 201. The third laser light generating means 300 includes a CBO crystal. The continuous wave light source 104, the optical modulator 106, and the optical amplifier 108 are not particularly limited, but are as described above, for example. The second harmonic generation means 110 is not particularly limited, but is similar to the apparatus of FIG. 9, for example. Third harmonic generation means 1030, fourth harmonic generation means 1040, fifth harmonic generation means 1050, sixth harmonic generation means 1060, seventh harmonic generation means 1070, and eighth harmonic generation means 1080 are: There is no particular limitation. For example, each of the harmonic generation means 1030 to 1080 may include an appropriate NLO (nonlinear optical crystal) and perform conversion into the second harmonic by the NLO. The type, crystal form, etc. of the NLO are not particularly limited. For example, various NLOs as described above can be used, and can be appropriately selected according to the wavelength of incident light.

  The laser beam generation method using the apparatus of FIG. 10 can be performed as follows, for example. The wavelength is an example for convenience of explanation, and is not limited thereto. That is, first, a continuous wave 105 (wavelength 1550 nm) is generated from the continuous wave light source 104. The continuous wave 105 is converted into a pulse wave 107 (wavelength 1550 nm) by the optical modulator 106. Further, the pulse wave 107 is amplified by the optical amplifier 108 to obtain a fundamental wave 201 (wavelength 1550 nm). The fundamental wave 201 is converted into the second harmonic 111 (wavelength 775 nm) by the second harmonic generation means 110. Next, the third harmonic generation means 1030 is irradiated with the second harmonic 111 (wavelength 775 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the first second harmonic generation means 110, and the sum frequency. By mixing, the third harmonic 1031 (wavelength 517 nm) is obtained. Further, the third harmonic wave 1031 (wavelength 517 nm) and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the third harmonic wave generation means 1030 are irradiated to the fourth harmonic wave generation means 1040, and sum frequency mixing is performed. The fourth harmonic 1041 (wavelength 388 nm) is used. Further, the fourth harmonic wave 1041 (wavelength 388 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the fourth harmonic wave generation means 1040 are irradiated to the fifth harmonic wave generation means 1050, and sum frequency mixing is performed. The fifth harmonic is 1051 (wavelength: 310 nm). Further, the fifth harmonic 1051 (wavelength 310 nm) and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the fifth harmonic generation means 1050 are irradiated to the sixth harmonic generation means 1060, and the sum frequency is mixed. The sixth harmonic 1061 (wavelength 258 nm) is used. Further, the sixth harmonic 1061 (wavelength 258 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the sixth harmonic generation means 1060 are irradiated to the seventh harmonic generation means 1070, and sum frequency mixing is performed. The seventh harmonic 1071 (wavelength 221 nm) is used. Furthermore, the seventh harmonic 1071 (wavelength 221 nm) and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the seventh harmonic generation means 1070 are irradiated to the eighth harmonic generation means 1080, and sum frequency mixing is performed. Eight harmonics (wavelength 194 nm). The eighth harmonic wave that has passed through the eighth harmonic generation means 1080 is referred to as the first laser beam 101, and the residual fundamental wave that has passed through the eighth harmonic generation means 1080 is referred to as the second laser beam 201. Then, the first laser beam 101 (wavelength 194 nm) and the second laser beam 201 (wavelength 1550 nm) are applied to the CBO crystal in the third laser beam generating means, and the sum frequency is mixed to produce the ninth harmonic, that is, the third laser beam. 301 (wavelength 172 nm) is generated. As described above, the laser beam generation method using the apparatus of FIG. 10 can be performed.

  Further, in FIGS. 9 and 10, the light transmitted through each harmonic generation means, the third laser light generation means 300, etc. may be, for example, mixed light having a plurality of wavelengths including residual incident light. In this case, as described above, the transmitted light may be separated for each wavelength by an appropriate separation unit, and only necessary light may be used.

  Furthermore, in the apparatus of FIG. 10, the fifth harmonic generation means 1050 and the sixth harmonic generation means 1060 can be omitted. FIG. 11 schematically shows an example of such an apparatus. As shown, this apparatus is the same as the apparatus of FIG. 10 except that there is no fifth harmonic generation means 1050 and sixth harmonic generation means 1060 and that it includes wavelength selective reflection mirrors 5000, 5000 ′ and 5000 ″. It is the same. The continuous wave light source 104, the optical modulator 106, and the optical amplifier 108 are not particularly limited, but are as described above, for example. The second harmonic generation means 110, the third harmonic generation means 1030, the fourth harmonic generation means 1040, the seventh harmonic generation means 1070, and the eighth harmonic generation means 1080 are not particularly limited. 9 and the apparatus of FIG. The second harmonic generation means 110 is preferably, for example, an LBO crystal or PPLN from the viewpoint of the second harmonic generation efficiency and the like. The third harmonic generation means 1030 is preferably, for example, an LBO crystal or PPLN from the viewpoint of harmonic generation efficiency and the like. The fourth harmonic generation means 1040 is preferably, for example, an LBO crystal, a BBO crystal, or a CLBO crystal from the viewpoint of harmonic generation efficiency and the like. The seventh harmonic generation means 1070 is preferably, for example, a BBO crystal from the viewpoint of harmonic generation efficiency and the like. The eighth harmonic generation means 1080 is preferably, for example, a CLBO crystal, an SBBO crystal, or a CBO crystal from the viewpoint of the second harmonic generation efficiency and the like.

  The laser beam generation method using the apparatus of FIG. 11 can be performed as follows, for example. In the following description and the description in FIG. 11, the wavelength is an example for convenience of description, and is not limited thereto. That is, first, a continuous wave 105 (wavelength 1550 nm) is generated from the continuous wave light source 104. The continuous wave 105 is converted into a pulse wave 107 (wavelength 1550 nm) by the optical modulator 106. Further, the pulse wave 107 is amplified by the optical amplifier 108 to obtain a fundamental wave 201 (wavelength 1550 nm). The fundamental wave 201 is converted into the second harmonic 111 (wavelength 775 nm) by the second harmonic generation means 110. Next, the third harmonic generation means 1030 is irradiated with the second harmonic 111 (wavelength 775 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the first second harmonic generation means 110, and the sum frequency. By mixing, the third harmonic 1031 (wavelength 517 nm) is obtained. Further, the third harmonic 1031 (wavelength 517 nm), the residual second harmonic 111 (wavelength 775 nm) and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the third harmonic generation means 1030 are converted into fourth harmonic generation means. Irradiated to 1040, and sum frequency mixing is performed to obtain the fourth harmonic 1041 (wavelength 388 nm). The fourth harmonic 1041 (wavelength 388 nm), the residual third harmonic 1031 (wavelength 517 nm), the residual second harmonic 111 (wavelength 775 nm), and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the fourth harmonic generation means 1040. ) Is irradiated on one side of the wavelength selective reflection mirror 5000. The residual second harmonic 111 (wavelength 775 nm) is transmitted through the wavelength selective reflection mirror 5000, and the other light is reflected by the wavelength selective reflection mirror 5000. The fourth harmonic wave 1041 (wavelength 388 nm), the third harmonic wave 1031 (wavelength 517 nm), and the fundamental wave 201 (wavelength 1550 nm) reflected by the wavelength selective reflection mirror 5000 are converted into seventh harmonic generation means 1070. The fourth harmonic 1041 (wavelength 388 nm) and the third harmonic 1031 (wavelength 517 nm) are sum-frequency mixed to obtain a seventh harmonic 1071 (wavelength 221 nm). The seventh harmonic 1071 (wavelength 221 nm), the residual fourth harmonic 1041 (wavelength 388 nm), the residual third harmonic 1031 (wavelength 517 nm), and the residual fundamental wave 201 (wavelength) transmitted through the seventh harmonic generation means 1070 1550 nm) is applied to one side of the wavelength selective reflection mirror 5000 ′. The residual fourth harmonic 1041 (wavelength 388 nm) and the residual third harmonic 1031 (wavelength 517 nm) are transmitted through the wavelength selective reflection mirror 5000 ′, and the other light is reflected by the wavelength selective reflection mirror 5000 ′. . The seventh harmonic 1071 (wavelength 221 nm) and the residual fundamental wave 201 (wavelength 1550 nm) reflected by the wavelength selective reflection mirror 5000 ′ are irradiated to the eighth harmonic generation means 1080, and the eighth harmonic is mixed by sum frequency mixing. Wave (wavelength 194 nm). The eighth harmonic wave (wavelength 194 nm), the residual seventh harmonic wave 1071 (wavelength 221 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the eighth harmonic wave generation means 1080 are transmitted to the wavelength selective reflection mirror 5000 ″. Irradiate one side. The eighth harmonic (wavelength 194 nm) and the residual fundamental wave 201 (wavelength 1550 nm) are transmitted through the wavelength selective reflection mirror 5000 ″, and the residual seventh harmonic 1071 (wavelength 221 nm) is the wavelength selective reflection mirror. Reflected by 5000 ″. The eighth harmonic wave that has passed through the wavelength selective reflection mirror 5000 ″ is the first laser beam 101, and the residual fundamental wave that has passed through the wavelength selective reflection mirror 5000 ″ is the second laser beam 201. Then, the first laser beam 101 (wavelength 194 nm) and the second laser beam 201 (wavelength 1550 nm) are applied to the CBO crystal 310 in the third laser beam generating means, and the sum frequency is mixed to produce the ninth harmonic, that is, the third laser. Light 301 (wavelength 172 nm) is generated. The residual first laser light 101 and the residual second laser light 201 transmitted through the CBO crystal 310 together with the third laser light 301 (wavelength 172 nm) may be separated from the third laser light 301 by an appropriate separation means. As described above, the laser beam generation method using the apparatus of FIG. 11 can be performed.

  Furthermore, the apparatus described in FIG. 10 or 11 can be variously modified in addition to this. An example is shown in FIG. As shown in the drawing, this apparatus has wavelength selective reflection mirrors 5000 to 5008 instead of wavelength selective reflection mirrors 5000 to 5000 '', and the harmonic generation and sum frequency mixing mechanisms are slightly different. It is the same as the apparatus of FIG. The second harmonic generation means 110, the third harmonic generation means 1030, the fourth harmonic generation means 1040, the seventh harmonic generation means 1070, and the eighth harmonic generation means 1080 are not particularly limited. For example, FIG. This is the same as the apparatus. Other components are not particularly limited, and may be the same as those shown in FIG. There are no particular restrictions on the positional relationship, coupling relationship, and the like of each component, and it is only necessary to be able to perform the following laser light generation method.

  The laser beam generation method using the apparatus of FIG. 12 can be performed as follows, for example. In the following description, the wavelength is an example for convenience of description, and is not limited thereto. That is, first, a continuous wave 105 (wavelength 1550 nm) is generated from the continuous wave light source 104. The continuous wave 105 is converted into a pulse wave 107 (wavelength 1550 nm) by the optical modulator 106. Further, the pulse wave 107 is amplified by the optical amplifier 108 to obtain a fundamental wave 201 (wavelength 1550 nm). The fundamental wave 201 is sequentially reflected by the wavelength selective reflection mirrors 5000 and 5001 and irradiated to the second harmonic generation means 110. The wavelength selective reflection mirrors 5000 and 5001 may be omitted, changed, or added as appropriate. Then, the fundamental wave 201 is converted by the second harmonic generation means 110 into the second harmonic 111 (wavelength 775 nm). Next, the third harmonic generation means 1030 is irradiated with the second harmonic 111 (wavelength 775 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the first second harmonic generation means 110, and the sum frequency. By mixing, the third harmonic 1031 (wavelength 517 nm) is obtained. Further, the third harmonic 1031 (wavelength 517 nm), the residual second harmonic 111 (wavelength 775 nm) and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the third harmonic generation means 1030 are converted into a wavelength selective reflection mirror 5002. Is irradiated on one side of the film, and only the third harmonic 1031 is reflected. The residual second harmonic 111 (wavelength 775 nm) and residual fundamental wave 201 (wavelength 1550 nm) transmitted through the wavelength selective reflection mirror 5002 are irradiated to one surface of the wavelength selective reflection mirror 5003 to reflect the second harmonic 111. The fundamental wave 201 is transmitted. This residual second harmonic 111 (wavelength 775 nm) is applied to the fourth harmonic generation means 1040 to make the second harmonic of the residual second harmonic 111, that is, the fourth harmonic 1041 (wavelength 388 nm). The fourth harmonic 1041 (wavelength 388 nm) transmitted through the fourth harmonic generation means 1040 is irradiated on one surface of the wavelength selective reflection mirror 5005 and reflected. On the other hand, the third harmonic wave 1031 (wavelength 517 nm) reflected by the wavelength selective reflection mirror 5002 is reflected by the wavelength selective reflection mirror 5004, and further irradiated and transmitted from the other surface of the wavelength selective reflection mirror 5005. The third harmonic 1031 (wavelength 517 nm) transmitted through the wavelength selective reflection mirror 5005 and the fourth harmonic 1041 (wavelength 388 nm) reflected by the wavelength selective reflection mirror 5005 are sent to the seventh harmonic generation means 1070. Irradiation and sum frequency mixing are performed to obtain a seventh harmonic 1071 (wavelength 221 nm). Of the seventh harmonic 1071 (wavelength 221 nm), residual fourth harmonic 1041 (wavelength 388 nm), and residual third harmonic 1031 (wavelength 517 nm) transmitted through the seventh harmonic generation means 1070, the seventh harmonic 1071 (wavelength 221 nm) is applied to one surface of the wavelength selective reflection mirror 5007 to be reflected. On the other hand, the fundamental wave 201 transmitted through the wavelength selective reflection mirror 5003 is reflected by the wavelength selective reflection mirror 5006, and further irradiated to and transmitted through the other surface of the wavelength selective reflection mirror 5007. The eighth harmonic generation means 1080 is irradiated with the fundamental wave 201 (wavelength 1550 nm) transmitted through the wavelength selective reflection mirror 5007 and the seventh harmonic 1071 (wavelength 221 nm) reflected by the wavelength selective reflection mirror 5007. , And sum frequency mixing to obtain the eighth harmonic (wavelength 194 nm). The eighth harmonic wave (wavelength 194 nm), the residual seventh harmonic wave 1071 (wavelength 221 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the eighth harmonic wave generation means 1080 are transmitted to one side of the wavelength selective reflection mirror 5008 Irradiate. The eighth harmonic (wavelength 194 nm) and the residual fundamental wave 201 (wavelength 1550 nm) are transmitted through the wavelength selective reflection mirror 5008, and the residual seventh harmonic 1071 (wavelength 221 nm) is transmitted by the wavelength selective reflection mirror 5008. Reflected. The eighth harmonic wave that has passed through the wavelength-selective reflection mirror 5008 is referred to as first laser light 101, and the residual fundamental wave that has passed through the wavelength-selective reflection mirror 5008 is referred to as second laser light 201. Then, the first laser beam 101 (wavelength 194 nm) and the second laser beam 201 (wavelength 1550 nm) are applied to the CBO crystal 310 in the third laser beam generating means, and the sum frequency is mixed to produce the ninth harmonic, that is, the third laser. Light 301 (wavelength 172 nm) is generated. The residual first laser light 101 and the residual second laser light 201 transmitted through the CBO crystal 310 together with the third laser light 301 (wavelength 172 nm) may be separated from the third laser light 301 by an appropriate separation means. As described above, the laser beam generation method using the apparatus of FIG. 12 can be performed.

  FIG. 13 shows an example of still another apparatus. As shown in the figure, this apparatus has wavelength selective reflection mirrors 5000 to 5007 in place of the wavelength selective reflection mirrors 5000 to 5000 ″, and sixth harmonic generation means in place of the fourth harmonic generation means 1041. Except for having 1061, it is the same as the apparatus of FIG. The second harmonic generation means 110, the third harmonic generation means 1030, the seventh harmonic generation means 1070, and the eighth harmonic generation means 1080 are not particularly limited, but are the same as, for example, the apparatus of FIG. The sixth harmonic generation means 1060 is not particularly limited, and examples thereof include a CLBO crystal and a BBO crystal. Other components are not particularly limited, and may be the same as those shown in FIG. There are no particular restrictions on the positional relationship, coupling relationship, and the like of each component, and it is only necessary to be able to perform the laser light generation method described below.

  The laser beam generation method using the apparatus of FIG. 13 can be performed as follows, for example. In the following description, the wavelength is an example for convenience of description, and is not limited thereto. That is, first, a continuous wave 105 (wavelength 1550 nm) is generated from the continuous wave light source 104. The continuous wave 105 is converted into a pulse wave 107 (wavelength 1550 nm) by the optical modulator 106. Further, the pulse wave 107 is amplified by the optical amplifier 108 to obtain a fundamental wave 201 (wavelength 1550 nm). This fundamental wave 201 irradiates one side of the wavelength selective reflection mirror 5000, reflects a part thereof and transmits a part thereof. The fundamental wave 201 transmitted through the wavelength selective reflection mirror 5000 is converted by the second harmonic generation means 110 into the second harmonic 111 (wavelength 775 nm). Next, the third harmonic generation means 1030 is irradiated with the second harmonic 111 (wavelength 775 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the first second harmonic generation means 110, and the sum frequency. By mixing, the third harmonic 1031 (wavelength 517 nm) is obtained. Further, the third harmonic 1031 (wavelength 517 nm), the residual second harmonic 111 (wavelength 775 nm), and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the third harmonic generation means 1030 are converted into a wavelength selective reflection mirror 5001. Is irradiated on one side of the light beam, only the third harmonic 1031 (wavelength 517 nm) is reflected, and other light is transmitted. The third harmonic 1031 (wavelength 517 nm) reflected by the wavelength selective reflection mirror 5001 is further reflected by the wavelength selective reflection mirror 5003 and irradiated to the sixth harmonic generation means 1060, and the third harmonic 1031. The second harmonic, that is, the sixth harmonic 1061 (wavelength 258 nm) is converted. Then, the third harmonic 1031 (wavelength 517 nm) and the sixth harmonic 1061 (wavelength 258 nm) transmitted through the sixth harmonic generation means 1060 are irradiated to one surface of the wavelength selective reflection mirror 5004, and the third harmonic 1031 ( The sixth harmonic 1061 (wavelength 258 nm) is reflected by transmitting the wavelength 517 nm.

  On the other hand, the residual second harmonic 111 (wavelength 775 nm) and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the wavelength selective reflection mirror 5001 are irradiated to one surface of the wavelength selective reflection mirror 5002, and the second harmonic. The wave 111 is transmitted and the residual fundamental wave 201 is reflected. The residual fundamental wave 201 reflected by the wavelength selective reflection mirror 5002 is irradiated and transmitted to the other surface of the wavelength selective reflection mirror 5004. The residual harmonic wave 201 (wavelength 1550 nm) transmitted through the wavelength selective reflection mirror 5004 and the sixth harmonic wave 1061 (wavelength 258 nm) reflected by the wavelength selective reflection mirror 5004 are irradiated to the seventh harmonic generation means 1070. , And sum frequency mixing to obtain a seventh harmonic 1071 (wavelength 221 nm). The seventh harmonic 1071 (wavelength 221 nm), the residual sixth harmonic 1061 (wavelength 258 nm) and the residual fundamental wave 201 (wavelength 1550 nm) transmitted through the seventh harmonic generation means 1070 are reflected on one side of the wavelength selective reflection mirror 5006. , And transmits only the seventh harmonic 1071 (wavelength 221 nm) and reflects other light.

  On the other hand, the fundamental wave 201 (wavelength 1550 nm) reflected by the wavelength selective reflection mirror 5000 is further reflected by the wavelength selective reflection mirror 5005 and further irradiated to the other surface of the wavelength selective reflection mirror 5006 and reflected. . Irradiating the eighth harmonic generation means 1080 with the fundamental wave 201 (wavelength 1550 nm) reflected by the wavelength selective reflection mirror 5006 and the seventh harmonic 1071 (wavelength 221 nm) transmitted through the wavelength selective reflection mirror 5006; The sum frequency is mixed to obtain the eighth harmonic (wavelength 194 nm). The eighth harmonic wave (wavelength 194 nm), the residual seventh harmonic wave 1071 (wavelength 221 nm) and the residual fundamental wave 201 (wavelength 1550 nm) that have passed through the eighth harmonic wave generation means 1080 are transmitted to one side of the wavelength selective reflection mirror 5007. Irradiate. The eighth harmonic (wavelength 194 nm) and the residual fundamental wave 201 (wavelength 1550 nm) are transmitted through the wavelength selective reflection mirror 5007, and the residual seventh harmonic 1071 (wavelength 221 nm) is transmitted by the wavelength selective reflection mirror 5007. Reflected. The eighth harmonic wave that has passed through the wavelength selective reflection mirror 5007 is referred to as first laser light 101, and the residual fundamental wave that has passed through the wavelength selective reflection mirror 5007 is referred to as second laser light 201. Then, the first laser beam 101 (wavelength 194 nm) and the second laser beam 201 (wavelength 1550 nm) are applied to the CBO crystal 310 in the third laser beam generating means, and the sum frequency is mixed to produce the ninth harmonic, that is, the third laser. Light 301 (wavelength 172 nm) is generated. The residual first laser light 101 and the residual second laser light 201 transmitted through the CBO crystal 310 together with the third laser light 301 (wavelength 172 nm) may be separated from the third laser light 301 by an appropriate separation means. As described above, the laser beam generation method using the apparatus of FIG. 13 can be performed.

In the apparatus as shown in FIGS. 10 to 13, the first laser light irradiation means 100 and the second laser light irradiation means 200 are, for example, the non-patent document 1, that is, T.A. Ohtsuki, H. et al. Kitano, H.M. Kawai, and S.K. Owa, "Efficient 193nm generation by eighth harmonic of Er 3+ -doped fiber amplifier", in Conference on Lasers and Electro-Optics 2000, postdeadline paper, (Optical Society of America, San Francisco, CA, 2000), p. paper CPD9. Non-Patent Document 2, that is, H.C. Kawai, A.A. Tokuhisa, M .; Doi, S .; Miwa, H.M. Matsuura, H .; Kitano, and S.K. Owa, “UV light source using fiber amplifier and non-linear waveguide conversion”, in Conference on Lasers and Electro-Optics 2003, paper CT3, paper CT. It can design suitably with reference to literatures. However, these apparatuses are not limited to the description in the above-mentioned document, and can be appropriately changed as described above. For example, the wavelength selective reflection mirror or the like may be appropriately omitted, changed, or added so that laser light irradiation, sum frequency mixing, and the like can be appropriately performed. Further, the positional relationship, coupling relationship, and the like of each component may be changed in any way as long as the laser beam generation method of the present invention can be appropriately performed.

  Next, still another example of the laser beam generation apparatus and the laser beam generation method of the present invention will be described.

In the laser beam generator of the present invention, for example, the first laser beam irradiation means may have the following configurations (i ′) and (ii ′).

(I ′) The first laser light irradiation means includes a first (C) pulse laser light generation means for generating a first (C) pulse laser light and a first (D) pulse laser light having a wavelength of 1540 to 1565 nm. A first (D) pulsed laser light generating means, a harmonic generating means (C) for converting the first (C) pulsed laser light into a harmonic, a first sum frequency mixing means, a second Sum frequency mixing means.
(Ii ′) The first (C) pulse laser beam is converted into a fourth harmonic by the harmonic generation means (C), and the fourth harmonic and the first (D) pulse laser beam are converted into the first harmonic. The sum frequency mixing is performed by one sum frequency mixing means, and the light obtained by the sum frequency mixing and the first (D) pulse laser light are again sum frequency mixed by the second sum frequency mixing means. A first laser beam is obtained.

From the viewpoint of the generation efficiency of the first laser beam, the first (C) pulse laser beam and the first (D) pulse laser beam are synchronized with the timing of the pulse as close as possible. preferable. The wavelength of the first (C) pulse laser beam is not particularly limited as long as the first laser beam can be obtained by the operation described in (ii ′). The wavelength of the first (C) pulse laser beam is, for example, 1030 to 1080 nm, preferably 1045 to 1070 nm, and more preferably 1064 to 1066 nm. The first (C) pulse laser light generating means is not particularly limited, and examples thereof include a YDFA light source, an Nd: YAG laser light source, an Nd: YVO ₄ laser light source, an Nd: YLF laser light source, a Yb: YAG laser light source, and the like. It is done. The first (D) pulse laser light generating means is not particularly limited, and examples thereof include an EDFA light source. The harmonic generation means (C), the first sum frequency mixing means, and the second sum frequency mixing means are not particularly limited. For example, an appropriate NLO (nonlinear optical crystal) according to the wavelength of the laser beam is used. Can be used. NLO (nonlinear optical crystal) is not particularly limited, but may be various NLOs as described above, for example. Further, the first laser light irradiation means includes the first (C) pulse laser light generation means, the first (D) pulse laser light generation means, the first sum frequency mixing means, and the second sum. Components other than the frequency mixing means may or may not be included as appropriate. There are no particular restrictions on the positional relationship, coupling relationship, or the like of each component, as long as the first laser beam can be obtained by the operation described in (ii ′). Further, the first (D) pulsed laser beam generating unit may also serve as the second laser beam irradiating unit, or the second laser beam irradiating unit may be provided separately. The first laser beam and the second laser beam may be continuous waves or pulse waves, respectively, but the first laser beam and the second laser beam are preferably pulse waves, and the timing of these pulses is It is more preferable to synchronize at a timing as close as possible.

  FIG. 14 shows an example of such a laser beam generator. As shown in the figure, this laser light generation apparatus includes a first laser light irradiation unit 100, a second laser light irradiation unit 200, and a third laser light generation unit 300 as main components. The first laser beam irradiation unit 100 includes a first (C) pulse laser beam generation unit 102, a first (D) pulse laser beam generation unit 2100, a harmonic generation unit (C), and a first sum frequency mixing. Means 1100 and second sum frequency mixing means 1200 are main components. The harmonic generation means (C) includes a first second harmonic generation means 110 and a second second harmonic generation means 120 as main components. The first laser light irradiation means 100 further includes wavelength selective reflection mirrors 5000 and 5000 '. The first laser light irradiation means 100 also serves as the second laser light irradiation means 200, and irradiates the CBO crystal in the third laser light generation means 300 with both the first laser light 101 and the second laser light 201. be able to. The first second harmonic generation means 110 preferably includes a crystal such as a KTP crystal, an LBO crystal, a PPLN crystal, or a PPLT crystal from the viewpoint of the second harmonic generation efficiency and the like. The second second harmonic generation means 120 preferably includes a crystal such as a BBO crystal or a CLBO crystal from the viewpoint of the generation efficiency of the second harmonic. The first sum frequency mixing means 1100 preferably includes a crystal such as a BBO crystal, an LBO crystal, or a CLBO crystal from the viewpoint of the sum frequency mixing efficiency and the like. The second sum frequency mixing means 1200 preferably includes a crystal such as a BBO crystal or a CLBO crystal from the viewpoint of the sum frequency mixing efficiency and the like. The positional relationship and the coupling relationship of the constituent elements are not particularly limited as long as the laser light generation method described below can be performed.

  The laser beam generation method using the apparatus of FIG. 14 can be implemented as follows, for example. In the following description and the description in FIG. 14, the forming material of each component and the wavelength of light are examples for convenience of description, and are not limited thereto. That is, first, the first (C) pulse laser beam 103 (wavelength 1064 nm) is generated from the first (C) pulse laser beam generator 102 (YDFA light source). This is converted into a second harmonic (wavelength of 532 nm) by the first second harmonic generation means 110, and further, the second second harmonic generation means 120 converts the second second harmonic, ie, the first ( C) The pulse laser beam 103 is converted into the fourth harmonic 121 (wavelength 266 nm). The fourth harmonic 121 (wavelength 266 nm) is applied to one surface of the wavelength selective reflection mirror 5000 from a direction inclined with respect to the surface. The fourth harmonic 121 (wavelength 266 nm) is transmitted through the wavelength selective reflection mirror 5000. On the other hand, the first (D) pulse laser beam 201 (wavelength 1564 nm) is generated from the first (D) pulse laser beam generation means 2100 (EDFA light source). The first (D) pulse laser beam 201 (wavelength 1564 nm) is irradiated to the other surface of the wavelength selective reflection mirror 5000 from a direction inclined with respect to the surface. The first (D) pulse laser beam 201 (wavelength 1564 nm) is reflected by the wavelength selective reflection mirror 5000. The first (D) pulsed laser beam 201 (wavelength 1564 nm) reflected by the wavelength selective reflection mirror 5000 and the fourth harmonic 121 (wavelength 266 nm) transmitted through the wavelength selective reflection mirror 5000 overlap and are the same. In the direction, both are incident on the first sum frequency mixing means 1100. The incident light is sum-frequency mixed by the first sum-frequency mixing unit 1100 to obtain sum-frequency mixed light 1101 (wavelength 227 nm). The light 1101 (wavelength 227 nm), the remaining fourth harmonic 121 (wavelength 266 nm), and the remaining first (D) pulsed laser light 201 (wavelength 1564 nm) are all transmitted through the first sum frequency mixing means 1100. To do. Both of these lights are applied to one surface of the wavelength selective reflection mirror 5000 '. The remaining fourth harmonic 121 (wavelength 266 nm) is transmitted through the wavelength selective reflection mirror 5000 ', and the other light is reflected by the wavelength selective reflection mirror 5000'. The light 1101 (wavelength 227 nm) reflected by the wavelength selective reflection mirror 5000 ′ and the remaining first (D) pulsed laser light 201 (wavelength 1564 nm) are further summed by the second sum frequency mixing means 1200. The first laser beam 101 (pulse laser beam, wavelength 198 to 199 nm) is used. At this time, the remaining first (D) pulsed laser light 201 (wavelength 1564 nm) transmitted through the second sum frequency mixing unit 1200 is set as the second laser light. Then, the first laser beam 101 and the second laser beam 201 are irradiated to the CBO crystal 310 in the third laser beam generating means 300 to be sum frequency mixed to obtain the third laser beam 301 (wavelength 175 nm). As described above, the laser beam generation method using the apparatus of FIG. 14 can be performed.

  In the apparatus shown in FIG. 14, the first laser light irradiation means 100 and the second laser light irradiation means 200 are, for example, the above-mentioned Patent Document 1 (Japanese Patent Laid-Open No. 2007-086101) or Patent Document 3 (United States). The design can be made as appropriate with reference to Japanese Patent Application Publication No. 2007/0064749. However, this apparatus is not limited to the description in the above-mentioned document, and can be appropriately changed as described above. For example, in the apparatus of FIG. 14, when the light 1101 incident on the sum frequency mixing means 1200 remains and passes through the sum frequency mixing means 1200, it is removed by an appropriate separation means such as a wavelength selective reflection mirror. Also good. Further, for example, when the remaining first laser light 101 and second laser light 201 are transmitted through the CBO crystal 310, they may be removed by an appropriate separation means such as a wavelength selective reflection mirror.

  Another example of the laser beam generator and laser beam generation method of the present invention will be described.

In the laser beam generator of the present invention, for example, the first laser beam irradiation means may have the following configurations (i ″) and (ii ″).

(I '') The first laser light irradiation means includes a first (C) pulse laser light generation means for generating a first (C) pulse laser light, and a first (D) pulse laser light having a wavelength of 1540 to 1565 nm. First (D) pulsed laser light generating means, harmonic generating means (C) for converting the first (C) pulsed laser light into harmonics, and the first (D) pulsed laser light as harmonics. Harmonic generation means (D) for converting into waves and sum frequency mixing means are included.
(Ii '') The first (C) pulsed laser beam is converted into a fourth harmonic by the harmonic generation unit (C), and the first (D) pulsed laser beam is converted into the harmonic generation unit (D). To the second harmonic, and the fourth harmonic of the first (C) pulsed laser beam and the second harmonic of the first (D) pulsed laser beam are sum frequency mixed by the sum frequency mixing means. To obtain the first laser beam.

That is, in the laser light generation device, the first laser light irradiation means further includes a harmonic generation means (D), and the fourth harmonic of the first (C) pulsed laser light and the first (D) It is the same as that of the apparatus of the said Example 6 except obtaining the said 1st laser beam by sum frequency mixing with the 2nd harmonic of a pulse laser beam by the said sum frequency mixing means. From the viewpoint of the generation efficiency of the first laser beam, the first (C) pulse laser beam and the first (D) pulse laser beam are synchronized with the timing of the pulse as completely as possible. preferable. The wavelength of the first (C) pulsed laser beam and the wavelength of the first (D) pulsed laser beam are not particularly limited, but are the same as, for example, the sixth embodiment. The first (C) pulse laser light generating means, the first (D) pulse laser light generating means, and the harmonic generation means (C) are not particularly limited, but are the same as, for example, the sixth embodiment. The harmonic generation means (D) and the sum frequency mixing means are not particularly limited, and for example, an appropriate NLO (nonlinear optical crystal) can be used according to the wavelength of the laser light. NLO (nonlinear optical crystal) is not particularly limited, but may be various NLOs as described above, for example. Further, the first laser light irradiation means includes the first (C) pulse laser light generation means, the first (D) pulse laser light generation means, the first (D) pulse laser light generation means, Components other than the sum frequency mixing means may or may not be included as appropriate. There are no particular restrictions on the positional relationship, coupling relationship, and the like of each component, as long as the first laser beam can be obtained by the operation described in (ii ''). Further, the first (D) pulsed laser beam generating unit may also serve as the second laser beam irradiating unit, or the second laser beam irradiating unit may be provided separately. The first laser light and the second laser light may be continuous waves or pulse waves, respectively, but the first laser light and the second laser light are preferably pulse waves, and the timing of these pulses is It is more preferable to synchronize at timings as close as possible.

  FIG. 15 shows an example of such a laser beam generator. As shown in the figure, this laser light generation apparatus includes a first laser light irradiation unit 100, a second laser light irradiation unit 200, and a third laser light generation unit 300 as main components. The first laser light irradiation means 100 includes a first (C) pulse laser light generation means 102, a first (D) pulse laser light generation means 2100, a harmonic generation means (C), and a harmonic generation means (D ) And the sum frequency mixing means 2200 are main components. The harmonic generation means (C) includes a first second harmonic generation means 110 and a second second harmonic generation means 120 as main components. The harmonic generation means (D) includes third second harmonic generation means 2110. The first laser light irradiation means 100 further includes wavelength selective reflection mirrors 5000 and 5000 '. The first laser light irradiation means 100 also serves as the second laser light irradiation means 200, and irradiates the CBO crystal in the third laser light generation means 300 with both the first laser light 101 and the second laser light 201. be able to. The first second harmonic generation means 110 preferably includes a crystal such as a KTP crystal, an LBO crystal, a PPLN crystal, or a PPLT crystal, from the viewpoint of the generation efficiency of the second harmonic. The second second harmonic generation means 120 preferably includes a crystal such as a BBO crystal or a CLBO crystal from the viewpoint of the generation efficiency of the second harmonic. The third second harmonic generation means 2110 preferably includes a crystal such as an LBO crystal or PPLN from the viewpoint of the second harmonic generation efficiency and the like. The sum frequency mixing means 2200 preferably includes a crystal such as a BBO crystal from the viewpoint of the sum frequency mixing efficiency and the like. The positional relationship and the coupling relationship of the constituent elements are not particularly limited as long as the laser light generation method described below can be performed.

  The laser beam generation method using the apparatus of FIG. 15 can be implemented as follows, for example. In the following description and the description in FIG. 15, the forming material of each component and the wavelength of light are examples for convenience of description, and are not limited thereto. That is, first, the first (C) pulse laser beam 103 (wavelength 1064 nm) is generated from the first (C) pulse laser beam generator 102 (YDFA light source). This is converted into a second harmonic (wavelength of 532 nm) by the first second harmonic generation means 110, and further, the second second harmonic generation means 120 converts the second second harmonic, ie, the first ( C) The pulse laser beam 103 is converted into the fourth harmonic 121 (wavelength 266 nm). The fourth harmonic 121 (wavelength 266 nm) is applied to one surface of the wavelength selective reflection mirror 5000 from a direction inclined with respect to the surface. The fourth harmonic 121 (wavelength 266 nm) is transmitted through the wavelength selective reflection mirror 5000. On the other hand, the first (D) pulse laser beam 201 (wavelength 1564 nm) is generated from the first (D) pulse laser beam generation means 2100 (EDFA light source). This is converted into the second harmonic 202 (wavelength 782 nm) of the first (D) pulse laser beam 201 by the harmonic generation means (D), that is, the third second harmonic generation means 2110. Both the second harmonic 202 (wavelength 782 nm) and the remaining first (D) pulsed laser light 201 (wavelength 1564 nm) are transmitted through the third second harmonic generation means 2110. The transmitted light is irradiated on the other surface of the wavelength selective reflection mirror 5000 from a direction inclined with respect to the surface. Both the second harmonic 202 (wavelength 782 nm) and the remaining first (D) pulsed laser light 201 (wavelength 1564 nm) are reflected by the wavelength selective reflection mirror 5000. The second harmonic 202 (wavelength 782 nm) reflected by the wavelength selective reflection mirror 5000 and the remaining first (D) pulse laser beam 201 (wavelength 1564 nm) and the fourth harmonic transmitted through the wavelength selective reflection mirror 5000. The wave 121 (wavelength 266 nm) overlaps and travels in the same direction, and enters the sum frequency mixing means 2200 together. The fourth harmonic 121 (wavelength 266 nm) and the second harmonic 202 (wavelength 782 nm) are sum-frequency mixed by the sum frequency mixing means 2200 to become the first laser beam 101 (wavelength 198 to 199 nm). The remaining first (D) pulsed laser light 201 transmitted through the harmonic generation means (D) 2110 passes through the sum frequency mixing means 2200. This transmitted light is referred to as second laser light 201 (wavelength 1564 nm). The first laser beam 101 (wavelength 198 to 199 nm), the second laser beam 201 (wavelength 1564 nm), the residual second harmonic 202 (wavelength 782 nm), and the residual fourth harmonic transmitted through the sum frequency mixing means 2200 121 (wavelength 266 nm) is irradiated onto one surface of the wavelength selective reflection mirror 5000 ′. The remaining second harmonic 202 (wavelength 782 nm) and the remaining fourth harmonic 121 (wavelength 266 nm) are transmitted through the wavelength selective reflection mirror 5000 ′, the first laser beam 101 (wavelength 198 to 199 nm), the first Two laser beams 201 (wavelength 1564 nm) are reflected by the wavelength selective reflection mirror 5000 ′. Then, the reflected first laser beam 101 (wavelength 198 to 199 nm) and second laser beam 201 (wavelength 1564 nm) are irradiated to the CBO crystal 310 in the third laser beam generating means 300 to be sum frequency mixed, and the third frequency is mixed. Laser light 301 (wavelength 175 nm) is obtained. As described above, the laser beam generation method using the apparatus of FIG. 15 can be performed. In the apparatus as shown in FIG. 15, the first laser light irradiation means 100 and the second laser light irradiation means 200 are, for example, the above-mentioned Patent Document 2 (Japanese Patent Laid-Open No. 2007-086104) or Patent Document 4 (United States). The design can be made as appropriate with reference to Japanese Patent Application Publication No. 2007/0064750. However, this apparatus is not limited to the description in the above-mentioned document, and can be appropriately changed as described above.

  Next, still another example of the laser beam generation apparatus and the laser beam generation method of the present invention will be described.

  First, the first (A) laser beam generation means (device) 160 having the configuration shown in FIG. 2 was constructed as follows, and the first (A) laser beam having a wavelength of 244 nm was generated.

  As the fundamental wave generating means 102, an Nd: YAG laser (trade name T40-X30-106Q, 1 mJ / pulse, pulse width: 30 ns, PRF: 1 kHz) manufactured by Spectra Physics was used. As the first second harmonic generation means 110, an LBO crystal (type I) having a length (optical path length) of 12 mm was used. As the optical parametric oscillator (OPO) 140, a Single Resonant Oscillator formed from a KTP crystal (type II) having a length (optical path length) of 20 mm was used. Further, an LBO crystal (type I) having a length (optical path length) of 15 mm is stored in the same container (in the resonator) as the OPO 140, and this is stored in the second second harmonic generation means 120 (internal resonator type SHG). did. As the third second harmonic generation means 130, a β-BBO crystal (type I) having a length (optical path length) of 7 mm arranged outside the resonator was used.

  The first (A) laser light generation method using the first (A) laser light generation means (device) was performed according to the description of FIG. 2 described above. In the present embodiment, the wavelength of the first second harmonic 111 is 532 nm, and signal light 141 having a wavelength of 976 nm is generated from the OPO 140 (KTP crystal) using this as pump light. And the 2nd 2nd harmonic 121 (wavelength 488nm) was obtained with the 2nd 2nd harmonic generation means 120 (internal resonator type SHG). When the conversion efficiency from the first second harmonic 111 (pump light) to the second second harmonic 121 (wavelength 488 nm) was measured, it was about 5%. Further, the second second harmonic 121 (wavelength 488 nm) is condensed and incident on the third second harmonic generation means 130 (β-BBO crystal (type I)), and the third second harmonic 131 is generated. , Obtained as the fourth harmonic (wavelength 244 nm) of the signal light 141. Further, when the third second harmonic generation means 130 was changed from the β-BBO crystal to the CLBO crystal, light having a wavelength of 244 nm was obtained with even better conversion efficiency. Note that this apparatus can be used in various fields such as the production of fiber gratings in addition to being used as the first (A) laser beam generating means (apparatus) of the present invention.

  Next, in the laser beam generator shown in FIG. 8, a device was constructed in which the first (A) laser beam generator 160 was replaced with the first (A) laser beam generator (device) of the present embodiment. When this apparatus was used to perform the laser light generation method according to the above description, the third laser light 301 (wavelength of about 175 nm) could be obtained efficiently.

  As described above, according to the laser light generation apparatus and the laser light generation method of the present invention, it is possible to generate laser light having a short wavelength of 170 to 178 nm with high efficiency, stability, and long life. According to the present invention, for example, in semiconductor manufacturing, wafer inspection, and mask inspection, inspection that could not be realized in the past can be performed, and a great influence on the semiconductor industry is expected. For example, by applying the present invention to a semiconductor manufacturing process and a mask manufacturing process, it is possible to improve inspection accuracy, improve yield, reduce manufacturing cost, and the like. Further, the laser light generation apparatus and laser light generation method of the present invention are not limited to the above-mentioned applications such as semiconductor manufacturing, and can be applied to various applications.

FIG. 1 is a schematic diagram showing an outline of a laser beam generator of the present invention. FIG. 2 is a schematic diagram showing an example of the first laser beam irradiation means used in the laser beam generator of the present invention. FIG. 3 is a schematic view showing an example of a laser beam generator of the present invention. FIG. 4 is a schematic view showing another example of the laser beam generator of the present invention. FIG. 5 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 6 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 7 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 8 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 9 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 10 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 11 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 12 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 13 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 14 is a schematic view showing still another example of the laser beam generator of the present invention. FIG. 15 is a schematic view showing still another example of the laser beam generator of the present invention.

Explanation of symbols

100 First laser light irradiation means 101 First laser light 102 Fundamental wave generating means or first (C) pulse laser light generating means 102 ′ First (B) laser light generating means 102 ″ Second (A) laser light generating Means 104 Continuous wave light source 106 Optical modulator 108 Optical amplifier 110 First second harmonic generation means 120 Second second harmonic generation means 130 Third second harmonic generation means 140 Optical parametric oscillator (OPO)
150 Sum Frequency Mixing Unit 160 First (A) Laser Light Generation Unit 170 VECSEL
180 Optical Parametric Oscillator (OPO)
200 Second laser light irradiation means 201 Second laser light 300 Third laser light generation means 301 Third laser light 1030 Third harmonic generation means 1040 Fourth harmonic generation means 1050 Fifth harmonic generation means 1060 Sixth harmonic Generation means 1070 Seventh harmonic generation means 1080 Eighth harmonic generation means 1100, 1200, 2200 Sum frequency mixing means 2100 First (D) pulse laser beam generation means 2110 Second harmonic generation means

Claims (13)

First laser light irradiation means for irradiating the first laser light;
Second laser light irradiation means for irradiating the second laser light;
A laser beam generator comprising: a third laser beam generating means for generating a third laser beam by mixing the first laser beam and the second laser beam with a sum frequency;
A wavelength of the first laser beam is in a range of 190 to 200 nm;
A wavelength of the second laser light is in a range of 1540 to 1565 nm;
The third laser light generating means includes a CBO crystal, and the sum frequency mixing is performed by irradiating the CBO crystal with the first laser light and the second laser light; and
The laser beam generator according to claim 1, wherein a wavelength of the third laser beam is in a range of 170 to 178 nm. At least one of the first laser light irradiation means and the second laser light irradiation means includes at least one selected from the group consisting of an external resonator, an internal resonator, and a parametric oscillator, and the first laser light and the 2. The laser beam generator according to claim 1, wherein at least one of the second laser beams is light that has undergone resonance by at least one selected from the group consisting of the external resonator, the internal resonator, and the parametric oscillator. The laser beam generator according to claim 1 or 2, wherein the first laser beam and the second laser beam are continuous waves. 3. The laser beam generation according to claim 1, wherein the first laser beam and the second laser beam are pulse laser beams, and pulse timings of the first laser beam and the second laser beam are synchronized. apparatus. The first laser light irradiation means includes a first (A) laser light generation means, a first (B) laser light generation means, and the first (A) laser light and the first (B) laser light. The laser beam generator according to any one of claims 1 to 4, further comprising sum frequency mixing means for obtaining the first laser beam by sum frequency mixing. The first (A) laser beam generating means is
Fundamental wave generating means for generating a fundamental wave;
First second harmonic generation means;
An optical parametric oscillator,
Second second harmonic generation means;
A third second harmonic generation means,
The fundamental wave is converted to a second harmonic by the first second harmonic generation means,
Resonating the second harmonic generated from the first second harmonic generating means by the optical parametric oscillator;
The resonated light is converted into a second harmonic by the second second harmonic generation means,
The second harmonic generated from the second second harmonic generation means is further converted into the second harmonic by the third second harmonic generation means to obtain the first (A) laser beam. A light generator,
The laser beam generator according to claim 5. The first laser light irradiation means further includes a fundamental wave separating means in addition to the first (A) laser light generating means, the first (B) laser light generating means, and the sum frequency mixing means,
The fundamental wave generating means in the first (A) laser light generating means also serves as the first (B) laser light generating means, and the fundamental wave also serves as the first (B) laser light,
Separating the light generated from the first second harmonic generation means in the first (A) laser light irradiation means into a second harmonic and a fundamental wave by the fundamental wave separation means;
The separated fundamental wave is the first (B) laser beam,
The first (B) laser light and the first (A) laser light, which is the second harmonic generated from the third second harmonic generation means, are sum frequency mixed by the sum frequency mixing means. To generate laser light,
The laser beam generator according to claim 6. The first (A) laser beam generating means is
Excitation light generating means for generating excitation light;
VECSEL (external cavity surface emitting laser);
One or more harmonic generation means,
Resonating the excitation light directly with the VECSEL,
A laser beam generator for converting the resonated light into a harmonic by the harmonic generation unit and making the first (A) laser beam;
The laser beam generator according to claim 5. The first laser light irradiation means and the second laser light irradiation means each include a continuous wave light source, an optical modulator, and one or more optical amplifiers,
The continuous wave generated from the continuous wave light source is converted into a pulse wave by the optical modulator, the pulse wave is amplified by the optical amplifier, and the first laser beam and the second laser beam are respectively modulated by the optical modulation. 5. The laser beam generator according to claim 4, wherein the laser beam is light that has undergone conversion by an optical amplifier and amplification by the optical amplifier. A continuous wave laser light source, and the continuous wave laser light source serves as the continuous wave light source in the first laser light irradiation means and the continuous wave light source in the second laser light irradiation means,
The first laser light irradiation means further includes a harmonic generation means,
The first laser light is a pulsed laser light that has been converted by the first laser light irradiation means through the optical modulator and amplification by the optical amplifier, and further converted into an eighth harmonic by the harmonic generation means. ,
The second laser light is pulsed laser light that has undergone conversion by the optical modulator and amplification by the optical amplifier in the second laser light irradiation means,
The third laser light is a ninth harmonic of the second laser light;
The laser beam generator according to claim 9. The first laser light irradiation means is a first (C) pulse laser light generation means for generating a first (C) pulse laser light, and a first (D) pulse laser light having a wavelength of 1540 to 1565 nm. (D) Pulse laser light generating means, harmonic generating means (C) for converting the first (C) pulse laser light into harmonics, first sum frequency mixing means, and second sum frequency mixing means Including
The first (C) pulse laser beam is converted into a fourth harmonic by the harmonic generation means (C), and the fourth harmonic and the first (D) pulse laser beam are converted into the first sum frequency. The sum frequency mixing is performed by the mixing means, and the light obtained by the sum frequency mixing and the first (D) pulse laser light are again sum frequency mixed by the second sum frequency mixing means, and the first laser light is mixed. The laser beam generator according to claim 1, obtained. The first laser light irradiation means is a first (C) pulse laser light generation means for generating a first (C) pulse laser light, and a first (D) pulse laser light having a wavelength of 1540 to 1565 nm. (D) pulse laser light generating means, harmonic generating means (C) for converting the first (C) pulse laser light into a harmonic, and harmonics for converting the first (D) pulse laser light into a harmonic. Wave generation means (D) and sum frequency mixing means,
The first (C) pulsed laser light is converted into a fourth harmonic by the harmonic generation means (C), and the first (D) pulsed laser light is converted to a second harmonic by the harmonic generation means (D). And the fourth harmonic of the first (C) pulsed laser beam and the second harmonic of the first (D) pulsed laser beam are sum frequency mixed by the sum frequency mixing means, and the first laser is mixed. The laser beam generator according to any one of claims 1 to 4, which obtains light. A first laser beam generating step for generating a first laser beam;
A second laser beam generating step for generating a second laser beam;
A third laser beam generation step of generating a third laser beam by mixing the first laser beam and the second laser beam in a sum frequency,
A wavelength of the first laser beam is in a range of 190 to 200 nm;
A wavelength of the second laser light is in a range of 1540 to 1565 nm;
Irradiating the CBO crystal with the first laser light and the second laser light in the third laser light generating step, performing the sum frequency mixing with the CBO crystal; and
The method of generating laser light, wherein the wavelength of the third laser light is in a range of 170 to 178 nm.

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