WO2011148895A1 - 固体レーザ装置およびレーザシステム - Google Patents
固体レーザ装置およびレーザシステム Download PDFInfo
- Publication number
- WO2011148895A1 WO2011148895A1 PCT/JP2011/061754 JP2011061754W WO2011148895A1 WO 2011148895 A1 WO2011148895 A1 WO 2011148895A1 JP 2011061754 W JP2011061754 W JP 2011061754W WO 2011148895 A1 WO2011148895 A1 WO 2011148895A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- laser
- light
- solid
- laser beam
- master oscillator
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
- H01S5/0085—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping for modulating the output, i.e. the laser beam is modulated outside the laser cavity
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/08—Construction or shape of optical resonators or components thereof
- H01S3/08018—Mode suppression
- H01S3/08022—Longitudinal modes
- H01S3/08027—Longitudinal modes by a filter, e.g. a Fabry-Perot filter is used for wavelength setting
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
- H01S3/136—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling devices placed within the cavity
- H01S3/137—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling devices placed within the cavity for stabilising of frequency
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/23—Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media
- H01S3/2308—Amplifier arrangements, e.g. MOPA
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/3501—Constructional details or arrangements of non-linear optical devices, e.g. shape of non-linear crystals
- G02F1/3507—Arrangements comprising two or more nonlinear optical devices
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/353—Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams
- G02F1/354—Third or higher harmonic generation
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/37—Non-linear optics for second-harmonic generation
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/005—Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/005—Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping
- H01S3/0092—Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
- H01S3/0602—Crystal lasers or glass lasers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/08—Construction or shape of optical resonators or components thereof
- H01S3/081—Construction or shape of optical resonators or components thereof comprising three or more reflectors
- H01S3/0811—Construction or shape of optical resonators or components thereof comprising three or more reflectors incorporating a dispersive element, e.g. a prism for wavelength selection
- H01S3/0812—Construction or shape of optical resonators or components thereof comprising three or more reflectors incorporating a dispersive element, e.g. a prism for wavelength selection using a diffraction grating
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
- H01S3/139—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling the mutual position or the reflecting properties of the reflectors of the cavity, e.g. by controlling the cavity length
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
- H01S3/22—Gases
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/23—Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media
- H01S3/2375—Hybrid lasers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/23—Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media
- H01S3/2383—Parallel arrangements
Definitions
- the present disclosure relates to a solid-state laser device and a laser system.
- KrF excimer lasers that output laser light in the deep ultraviolet region and ArF excimer laser devices that output laser light in the vacuum ultraviolet region have been used as light sources for exposure in semiconductor device manufacturing.
- laser light output from a master oscillator using gas as a gain medium is amplified by an amplifier that also uses gas as a gain medium.
- a solid-state laser device is capable of changing a spectral line width of an output laser beam, and outputs a laser beam including at least one longitudinal mode, and a downstream side of the master oscillator.
- At least one amplifier disposed on the optical path, a wavelength converter disposed on the optical path downstream of the amplifier, a detection unit that detects the spectrum of the laser light, and a detection result of the detection unit
- a control unit that controls a spectral line width of the laser light output from the master oscillator.
- a laser system may include the above-described solid-state laser device and at least one amplifying device disposed on an optical path downstream of the solid-state laser device.
- FIG. 1 is a diagram for describing an overview of an embodiment of the present disclosure.
- FIG. 2 schematically shows a schematic configuration of the laser system according to the first embodiment of the present disclosure.
- FIG. 3 schematically shows a schematic configuration of the solid-state laser apparatus according to the first embodiment.
- FIG. 4 schematically shows a schematic configuration of the master oscillator including the Littman cavity according to the first embodiment.
- FIG. 5 schematically shows a schematic configuration of the master oscillator including the wavelength filter according to the first embodiment.
- FIG. 1 is a diagram for describing an overview of an embodiment of the present disclosure.
- FIG. 2 schematically shows a schematic configuration of the laser system according to the first embodiment of the present disclosure.
- FIG. 3 schematically shows a schematic configuration of the solid-state laser apparatus according to the first embodiment.
- FIG. 4 schematically shows a schematic configuration of the master oscillator including the Littman cavity according to the first embodiment.
- FIG. 5 schematically shows a schematic configuration of the master oscillator including the wavelength filter
- FIG. 6 shows the wavelength spectrum of the laser light oscillated by the Ti: sapphire crystal in Embodiment 1 and the wavelength selection characteristics of the birefringent filter, coarse and fine etalon.
- FIG. 7 shows the wavelength selection characteristics of the fine etalon and the longitudinal mode of the laser beam in the first embodiment.
- FIG. 8 schematically shows a schematic configuration of the fine etalon shown in FIG.
- FIG. 9 shows an example of an etalon.
- FIG. 10 shows the relationship between the FSR and FWHM of the etalon shown in FIG.
- FIG. 11 shows the Fines characteristic for each reflectance of the etalon shown in FIG.
- FIG. 12 schematically shows a schematic configuration of the master oscillator provided with the band narrowing element according to the first embodiment.
- FIG. 13 schematically shows a schematic configuration of the master oscillator provided with the band narrowing unit according to the first embodiment.
- FIG. 14 shows a schematic configuration of a master oscillator including the semiconductor laser according to the first embodiment.
- FIG. 15 schematically shows a schematic configuration of an example of the optical path controller shown in FIG.
- FIG. 18 schematically shows a schematic configuration of another example of the optical path controller shown in FIG. FIG.
- FIG. 19 shows a schematic configuration of a master oscillator including the optical modulator according to the first embodiment.
- FIG. 20 shows a schematic configuration of a master oscillator including the electro-optic element according to the first embodiment as an optical modulator.
- FIG. 21 shows an example of seed light output from the seed laser shown in FIG.
- FIG. 22 shows an example of laser light output from the electro-optic element shown in FIG.
- FIG. 23 shows a schematic configuration of a master oscillator provided with the photoacoustic element according to the first embodiment as an optical modulator.
- FIG. 24 shows an example of seed light output from the seed laser shown in FIG.
- FIG. 25 shows an example of laser light output from the first photoacoustic element shown in FIG.
- FIG. 24 shows an example of seed light output from the seed laser shown in FIG.
- FIG. 26 shows an example of laser light output from the second photoacoustic element shown in FIG.
- FIG. 27 schematically shows a schematic configuration of the amplifier of the Fabry-Perot type power oscillator according to the first embodiment.
- FIG. 28 schematically shows a schematic configuration of an amplifier configured as a ring-type power oscillator according to the first embodiment.
- FIG. 29 schematically shows a schematic configuration of the regenerative amplifier according to the first embodiment.
- FIG. 30 schematically shows a schematic configuration of an amplifier configured as a multipath type power amplifier according to the first embodiment.
- FIG. 31 schematically shows a schematic configuration of a wavelength conversion unit including two SHG crystals according to the first embodiment.
- FIG. 32 shows the laser beam output from the amplifier in the first embodiment.
- FIG. 33 shows the second harmonic light output from the BBO crystal with respect to the incidence of the laser light shown in FIG.
- FIG. 34 shows the fourth harmonic light output from the KBBF crystal with respect to the incidence of the laser light shown in FIG.
- FIG. 35 shows an example of a laser beam input as a fundamental wave to the wavelength converter according to the first embodiment.
- FIG. 36 shows fourth harmonic light generated using the BBO crystal and KBBF crystal with the laser light shown in FIG. 35 as the fundamental wave.
- FIG. 37 shows an example of a laser beam input as a fundamental wave to the wavelength converter according to the first embodiment.
- FIG. 38 shows fourth harmonic light generated using the BBO crystal and KBBF crystal with the laser light shown in FIG. 37 as a fundamental wave.
- FIG. 39 shows an example of a laser beam input as a fundamental wave to the wavelength conversion unit according to the first embodiment.
- FIG. 40 shows fourth harmonic light generated using the BBO crystal and KBBF crystal with the laser light shown in FIG. 39 as a fundamental wave.
- FIG. 41 schematically shows a schematic configuration of an example of the detection unit according to the first embodiment.
- FIG. 42 schematically shows a schematic configuration of another example of the detection unit according to the first embodiment.
- FIG. 43 is a diagram for explaining the spectral purity E95.
- FIG. 44 schematically shows a schematic configuration of an amplifying apparatus configured as a power oscillator according to the first embodiment.
- FIG. 45 schematically illustrates a schematic configuration of a laser system according to the second embodiment of the present disclosure.
- FIG. 45 schematically illustrates a schematic configuration of a laser system according to the second embodiment of the present disclosure.
- FIG. 46 schematically shows a schematic configuration of Modification 1 of the solid-state laser device.
- FIG. 47 schematically shows a schematic configuration of the low coherence unit shown in FIG.
- FIG. 48 schematically shows a schematic configuration of Modification 2 of the solid-state laser device.
- FIG. 49 schematically shows a schematic configuration of a laser system according to the third embodiment of the present disclosure.
- FIG. 50 schematically shows another cross-sectional configuration along the optical path of the amplification device shown in FIG.
- MOPO Master Oscillator Power Oscillator
- MOPA Master Oscillator Power Amplifier
- Modification Example of Solid-State Laser Device 5.1 Solid-state laser device including a low coherence unit (Modification Example 1) 5.1.1 Low coherence unit using optical pulse stretch 5.2 Solid-state laser device including wavelength conversion unit using LBO crystal and THG crystal (Modification 2) 6). A laser system using a power amplifier in an amplifying device (Embodiment 3)
- FIG. 1 is a diagram for explaining the outline of the embodiment exemplified below.
- the spectrum SP of the laser beam output from the light source has a relatively narrow band and an appropriate spread as shown in FIG.
- the spectral purity E95 shown in FIG. 1 may be a line width of a frequency region or a wavelength band in which 95% of light energy in the spectrum is concentrated.
- Such a spectrum SP may be approximately realized by using a plurality of longitudinal modes L1, L2,..., Ln as an example.
- strength of each longitudinal mode L1, L2, ..., Ln may be increased / decreased according to the shape of spectrum SP.
- a master oscillator as a seed light source used in a laser system is not always capable of outputting a laser beam having a spectrum SP having a relatively narrow band and an appropriate spread. Therefore, in the following embodiment, as shown in FIG. 1, a laser beam spectrum SP required from an external apparatus such as an exposure apparatus is used as a laser beam including a plurality of longitudinal modes L1, L2,. May be realized approximately. At that time, the center frequency of each longitudinal mode L1 to Ln, the frequency difference between adjacent longitudinal modes L1 to Ln (hereinafter referred to as longitudinal mode interval) and the light intensity of each longitudinal mode L1 to Ln are based on the shape of the spectrum SP. May be adjusted.
- Gaussian is illustrated as the shape of the spectrum SP.
- the present invention is not limited to this.
- various modifications can be made such as a top-hat spectrum having a relatively broad center wavelength, a spectrum having a plurality of peaks, and a spectrum having an asymmetric shape. That is, the following embodiments can correspond to various shapes of required spectra.
- the multi-longitudinal mode refers to including a plurality of longitudinal modes.
- the spectral line width of laser light including a plurality of longitudinal modes refers to the spectral line width of the entire laser light including a plurality of longitudinal modes.
- the laser beam may be a pulsed laser beam or a continuous laser beam.
- the amplifier and the amplifying device may include a power oscillator, a power amplifier, a regenerative amplifier, and the like.
- the power oscillator may include a gain medium for amplifying the laser light and an optical resonator.
- the power amplifier may include a gain medium for amplifying the laser light and one or more optical elements that form a path through the gain medium.
- the master oscillator may include a laser that outputs laser light in a multi-longitudinal mode, a laser oscillator, and the like.
- the laser system 1 As the laser system 1, an ArF laser whose output laser beam has a center wavelength of 193 nm is taken as an example. However, it is not limited to this. Various laser systems such as an excimer laser such as a KrF laser, a XeCl laser, and an XeF laser can be applied as the laser system 1.
- an excimer laser such as a KrF laser, a XeCl laser, and an XeF laser can be applied as the laser system 1.
- FIG. 2 schematically shows a schematic configuration of the laser system 1 according to the first embodiment.
- the laser system 1 may include a solid-state laser device 10 and an amplification device 80.
- the solid-state laser device 10 may output laser light 20 including a plurality of longitudinal modes that approximately realize the spectrum SP.
- the laser beam 20 output from the solid-state laser device 10 may be guided to the amplification device 80 by the optical system 30.
- the optical system 30 may include a plurality of high reflection mirrors 31 and 32 that highly reflect the laser light 20.
- the amplification device 80 may amplify the incident laser beam 20 and output it as the laser beam 40.
- the output laser beam 40 may be input to an exposure apparatus, for example.
- FIG. 3 schematically shows a schematic configuration of the solid-state laser apparatus 10.
- the solid-state laser device 10 may include a master oscillator 100, an amplifier 200, and a wavelength conversion unit 300.
- the master oscillator 100 may be a so-called seed light source.
- the master oscillator 100 may output laser light including at least one longitudinal mode as the laser light 21.
- the curve connecting the peak of the light intensity of each longitudinal mode included in the laser beam 21 may approximate the spectrum SP.
- the amplifier 200 may amplify the laser beam 21 and output it as the laser beam 22.
- the wavelength conversion unit 300 matches the wavelength of the laser beam 21 (or the laser beam 22 after amplification by the amplifier 200) output from the master oscillator 100 with the amplifiable wavelength region of the amplification device 80 that is an amplification stage.
- the wavelength of the laser beam 23 may be converted.
- the wavelength conversion device 300 may generate the fourth harmonic light using each longitudinal mode included in the laser light 22 as a fundamental wave.
- the wavelength conversion unit 300 may output the generated fourth harmonic light as the laser light 23.
- the solid-state laser device 10 may further include a beam splitter 410, a detection unit 420, and a control unit 430.
- the beam splitter 410 may be disposed on the optical path of the laser beam 23 output from the wavelength conversion unit 300.
- the beam splitter 410 may branch the optical path of the laser light 23 into two.
- the beam splitter 410 may be coated with a film that partially reflects the laser light 23.
- the laser beam 23 that has passed through the beam splitter 410 may be output from the solid-state laser device 10 as the laser beam 20.
- the laser beam 23 reflected by the beam splitter 410 may be incident on the detection unit 420 as the laser beam 24.
- the detection unit 420 may detect the spectral line width of the entire laser beam 24.
- the control unit 430 may perform feedback control on the master oscillator 100 based on the detected spectral line width. At this time, the control unit 430 may control the center frequency, the longitudinal mode interval, and the light intensity of each longitudinal mode L1 to Ln included in the laser light 21 output from the master oscillator 100. Further, the control unit 430 may perform feedback control of the master oscillator 100 in accordance with a request from the external apparatus 50 such as an exposure apparatus controller.
- FIG. 4 schematically shows a schematic configuration of the master oscillator 100 including the Littman cavity.
- the master oscillator 100 includes a high reflection mirror 101, a titanium sapphire crystal 102 as a gain medium, a grating 103, a high reflection mirror 104, an output coupler 105, and a pumping laser 106. Also good.
- the high reflection mirror 101 and the output coupler 105 may constitute an optical resonator.
- the titanium sapphire crystal 102 and the grating 103 may be disposed on the optical path in the optical resonator formed by the high reflection mirror 101 and the output coupler 105.
- the high reflection mirror 104 may reflect the laser light diffracted by the grating 103 and return it to the grating 103.
- the high reflection mirror 104 may be a deformable mirror whose reflection surface can change the curvature with respect to the dispersion direction of the grating 103.
- the high reflection mirrors 101 and 104 may form an optical resonator different from the optical resonator formed by the high reflection mirror 101 and the output coupler 105.
- the resonator length L sol 1 from the high reflection mirror 101 to the high reflection mirror 104 may be equal to the resonator length L sol 2 from the high reflection mirror 101 to the output coupler 105.
- the surface inside the optical resonator of the high reflection mirror 101 may be coated with a film that highly reflects light having a wavelength near 773.6 nm and highly transmits the excitation light 61 from the pumping laser 106.
- the opposite surface of the high reflection mirror 101 may be coated with a film that highly transmits the excitation light 61. Thereby, the high reflection mirror 101 can take the excitation light 61 from the pumping laser 106 into the optical resonator and reflect the laser light from the titanium sapphire crystal 102.
- the excitation light 61 that has entered the optical resonator via the high reflection mirror 101 may enter the titanium sapphire crystal 102.
- the light input / output end face of the titanium sapphire crystal 102 may be Brewster cut.
- the Brewster cut end face can suppress the reflection of the laser beam. Thereby, amplification efficiency can be improved.
- the polarization state of the laser light can be defined by Brewster cut. Therefore, the efficiency with which the excitation light 61 and the laser light are incident on the titanium sapphire crystal 102 can be improved.
- the laser light may be emitted from the titanium sapphire crystal 102.
- the laser light emitted from the titanium sapphire crystal 102 includes an optical resonator including the high reflection mirror 101, the grating 103, and the high reflection mirror 104, and the high reflection mirror 101, the grating 103, and the output coupler 105.
- the optical resonator may be reciprocated.
- the laser beam passing through the titanium sapphire crystal 102 may be amplified.
- the laser light that has passed through the titanium sapphire crystal 102 may be diffracted by the grating 103.
- the surface inside the optical resonator of the output coupler 105 may be coated with a film that partially reflects light having a wavelength near 773.6 nm.
- the opposite surface of the output coupler 105 may be coated with an antireflection film. Thereby, the output coupler 105 can function as an optical output terminal that outputs the laser light 21.
- the output coupler 105 may be arranged with respect to the grating 103, for example, in the emission direction of the 0th-order diffracted light.
- the high reflection mirror 104 may be disposed in the emission direction of the ⁇ mth order diffracted light with respect to the grating 103. According to such a configuration, the spectral line width of the laser light can be adjusted by adjusting the number of grooves per unit length of the grating 103. Further, the wavelength of the laser light 21 output from the master oscillator 100 can be selected by adjusting the angle of the high reflection mirror 104 with respect to the grating 103.
- the number of longitudinal modes of the laser light 21 output from the master oscillator 100 can be determined by the spectral line width and the longitudinal mode interval. Therefore, the number of grooves per unit length of the grating 103 is preferably designed so that the spectral line width of the entire laser beam 21 becomes the desired spectral line width of the spectrum SP. Further, the resonator lengths L sol 1 and L sol 2 of the master oscillator 100 may be designed to have a predetermined longitudinal mode interval. Thereby, the laser beam 21 having a desired number of longitudinal modes and a spectral line width can be generated.
- L sol of the master oscillator 100 when the laser system 1 is used as a light source for semiconductor exposure will be described.
- the longitudinal mode interval of the laser beam 40 output from the laser system 1 can be expressed as C / 2L EXC .
- C is the speed of light.
- L EXC is the resonator length of the master oscillator 100 for generating the laser light 21 including a plurality of longitudinal modes in which the peaks of the longitudinal modes are distributed so as to trace the spectrum SP suitable for semiconductor exposure, for example.
- ... ( ⁇ Ln ⁇ 1 ⁇ Ln
- the longitudinal mode interval ⁇ of the laser light 21 output from the master oscillator 100 can be expressed as C / 2L sol . Therefore, in order to obtain a desired longitudinal mode interval by the master oscillator 100, the resonator length L sol of the master oscillator 100 only needs to satisfy L SOL ⁇ L EXC .
- the resonator length L sol of the master oscillator 100 is preferably 1.00 m.
- the resonator length L sol of the master oscillator 100 may be, for example, not less than 0.5 m and not more than 1.5 m. More preferably, the resonator length L sol may be, for example, not less than 0.8 m and not more than 1.2 m. However, the lower limit of the resonator length L sol is preferably determined by a request from the exposure apparatus side, for example. The upper limit of the resonator length L sol is preferably determined based on ease of design and the like.
- the master oscillator 100 may include a drive mechanism that changes the reflection surface of the highly reflective mirror 104, which is a deformable mirror, in order to change the wavefront in the resonator.
- the drive mechanism may include a drive unit 101b that changes the curvature of the surface of the high reflection mirror 104.
- the control unit 430 may control the curvature of the reflection surface of the high reflection mirror 104 via the drive unit 101b.
- the case where the wavefront in the optical resonator is changed by the high reflection mirror 104 is illustrated.
- the curvatures of the reflecting surfaces of the grating 103, the high reflection mirror 101, and the output coupler 105 may be changed.
- FIG. 5 schematically shows a schematic configuration of the master oscillator 110 including the wavelength filter.
- the master oscillator 110 includes a high reflection mirror 111, a titanium sapphire crystal 112 as a gain medium, a coarse etalon 113, a fine etalon 114, a birefringence filter 115, an output coupler 116, and a pumping.
- a laser 117 may be provided.
- the high reflection mirror 111 and the output coupler 116 may constitute an optical resonator.
- the titanium sapphire crystal 112, the coarse etalon 113, the fine etalon 114, and the birefringent filter 115 may be disposed on the optical path in the optical resonator formed by the high reflection mirror 111 and the output coupler 116.
- the coarse etalon 113, the fine etalon 114, and the birefringence filter 115 may constitute a narrow band section 118.
- the surface inside the optical resonator of the high reflection mirror 111 may be coated with a film that highly reflects light having a wavelength near 773.6 nm and highly transmits the excitation light 61 from the pumping laser 117.
- the opposite surface of the high reflection mirror 111 may be coated with a film that highly transmits the excitation light 61. Thereby, the high reflection mirror 111 can take in the excitation light 61 from the pumping laser 117 into the optical resonator and reflect the laser light from the titanium sapphire crystal 112 to the inside of the optical resonator.
- the excitation light 61 that has entered the optical resonator via the high reflection mirror 111 may enter the titanium sapphire crystal 112.
- the light input / output end face of the titanium sapphire crystal 112 may be Brewster cut.
- Laser light may be emitted from the titanium sapphire crystal 112 excited by the excitation light 61.
- the laser beam may reciprocate in the optical resonator composed of the high reflection mirror 111 and the output coupler 116. As a result, the laser beam passing through the titanium sapphire crystal 112 may be amplified.
- the surface inside the optical resonator of the output coupler 116 may be coated with a film that partially reflects light having a wavelength near 773.6 nm.
- the opposite surface of the output coupler 116 may be coated with an antireflection film. Accordingly, the output coupler 116 can function as an optical output terminal that outputs the laser light 21.
- the birefringence filter 115, the coarse etalon 113, and the fine etalon 114 arranged in the optical resonator can each function as a wavelength filter.
- FIG. 6 shows the wavelength spectrum of the laser light oscillated by the titanium sapphire crystal 112 and the wavelength selection characteristics of the birefringence filter 115, the coarse etalon 113, and the fine etalon 114.
- FIG. 7 shows the wavelength selection characteristics of the fine etalon 114 and the longitudinal mode of the laser light 21.
- a laser beam having a spectrum B112 in which longitudinal modes are distributed in a relatively wide wavelength range of about 650 to 1100 nm can be output.
- the light transmission spectrum B114 of the fine etalon 114 is narrower than the spectrum B112 of the laser light.
- This light transmission spectrum B114 may be substantially equal to the desired spectrum SP (see FIG. 1). Therefore, by using the fine etalon 114 as a wavelength filter, the entire spectrum of the laser light 21 output from the master oscillator 110 can be substantially converted into a desired spectrum SP as shown in FIG.
- the light transmission band (light transmission spectrum B114) of the fine etalon 114 is not limited to one.
- the light transmission bands of the birefringent filter 115 and the coarse etalon 113 are not limited to one, respectively.
- the birefringent filter 115 may be inclined with respect to the optical path in the optical resonator so that the incident angle of the laser beam becomes the Brewster angle.
- Each of the two light input / output surfaces of the birefringent filter 115 may be coated with an antireflection film.
- the thickness along the optical path of the birefringent filter 115 may be a thickness that can function as a wave plate for light of, for example, 773.6 nm.
- the specular spacing and the reflectance of the coarse etalon 113 may be specifications such that the light transmission spectrum B113 is narrower than the light transmission spectrum B115 of the birefringence filter 115. As a result, the number of longitudinal modes transmitted through the birefringent filter 115 can be narrowed down by the coarse etalon 113.
- the coarse etalon 113 may be a solid etalon in which a film having a predetermined reflectance is coated on both surfaces of a predetermined substrate that transmits the wavelength of the laser.
- an air gap etalon in which two mirrors having a predetermined partial reflectance are combined at a predetermined mirror interval via a spacer may be used.
- the specular spacing and reflectance of the fine etalon 114 may be specifications such that the light transmission spectrum B114 is narrower than the light transmission spectrum B113 of the coarse etalon 113. At least one light input / output surface of the fine etalon 114 may be coated with a film such that the light transmission spectrum B114 is narrower than the light transmission spectrum B113 of the coarse etalon 113. Thereby, the number of longitudinal modes transmitted through the coarse etalon 113 can be further narrowed down by the fine etalon 114.
- the fine etalon may be a solid etalon or an air gap etalon.
- the pulsed excitation light 61 output from the pumping laser 117 may pass through the high reflection mirror 111 and enter the titanium sapphire crystal 112.
- the titanium sapphire crystal 112 can be excited.
- the titanium sapphire crystal 112 can emit light when transitioning from an excited state to a ground state. This light has a relatively wide spectral line width. Therefore, the laser light in the optical resonator may be narrowed by using the coarse etalon 113, the fine etalon 114, and the birefringence filter 115.
- the narrowband laser beam may be incident on the output coupler 116.
- the output coupler 116 may output a part of the laser light as the laser light 21 to the outside of the optical resonator.
- the output coupler 116 may reflect another part of the laser light into the optical resonator.
- the reflected laser light may be further narrowed by passing through the birefringence filter 115, the fine etalon 114, and the coarse etalon 113.
- the narrow-band laser beam may be amplified by passing through the titanium sapphire crystal 112.
- the amplified laser light may be further amplified by being folded back by the high reflection mirror 111 and passing through the titanium sapphire crystal 112 again.
- the amplified laser beam may be narrowed by passing through the coarse etalon 113, the fine etalon 114, and the birefringence filter 115 again.
- the narrowband laser beam may be incident on the output coupler 116.
- the output coupler 116 may output part of the laser light as the laser light 21 to the outside of the optical resonator and reflect the other part of the laser light into the optical resonator.
- the master oscillator 110 can oscillate by repeating such an operation, and can output a laser beam having a spectrum including a desired longitudinal mode.
- Both the light input / output surfaces of the fine etalon 114 may be coated with coatings having different reflectivities depending on the transmission position of the laser light. However, when the laser light passes through the etalon, the incident surface and the exit surface may have the same reflectance. For example, as shown in FIG. 8, both the light input / output surfaces of the fine etalon 114 are coated with a partial reflection film 114c in which the reflectance of both surfaces gradually changes in accordance with the position where the laser light is transmitted. Also good.
- FIG. 9 is a cross-sectional view illustrating an example of an etalon.
- FIG. 10 shows the relationship between the FSR (Free Spectral Range) and FWHM (Full Width at Half Maximum) of the etalon shown in FIG.
- FIG. 11 shows the Fines characteristic for each reflectance of the etalon shown in FIG.
- the etalon 1114 shown in FIG. 9 may be, for example, a Fabry-Perot etalon. Partial reflection films 1114a and 1114b may be coated on the light input / output surface of the etalon 1114, respectively.
- the etalon 1114 can have the effect of a wavelength filter in which a specific wavelength is strengthened by an interference effect between opposing reflecting surfaces (light input / output surfaces). Such characteristics of the etalon 1114 can usually be specified by FSR and F (Fineness). F can be expressed as the ratio of FSR and FWHM. Thus, F can be determined primarily by reflectivity.
- the substrate thickness of the etalon 1114 is d
- the refractive index of the substrate is n
- the reflectances of the partial reflection films 1114a and 1114b are R. Then, the following relational expressions (1) to (3) can be established. It should be noted, ⁇ denotes the wavelength of the laser light L in.
- F ⁇ R 1/2 / (1 ⁇ R) (1)
- FSR ⁇ 2 / (2nd) (2)
- FWHM FSR / F (3)
- the light transmission spectrum B1114 of the etalon 1114 can have a shape having a peak for each FSR, as shown in FIG. Further, as shown in FIG. 11, when the reflectance R of the partial reflection films 1114a and 1114b is increased, the light transmission spectrum B1114a of the etalon 1114 may have a shape in which very sharp peaks repeatedly appear. On the other hand, when the reflectance of the partial reflection films 1114a and 1114b is lowered, the light transmission spectrum B1114b has a relatively broad shape.
- the light transmission spectrum B1114 shows the case where the reflectance R is 50%
- the light transmission spectrum B1114a shows the case where the reflectance R is 90%
- the light transmission spectrum B1114b shows the case where the reflectance R is 4%. Is shown.
- the fine etalon 114 coated with the partial reflection film 114c whose reflectance gradually changes depending on the position may be moved in a direction in which the reflectance of the portion arranged in the optical path changes.
- the line width of the light transmission spectrum B114 of the fine etalon 114 can be controlled by moving the fine etalon 114 in the direction in which the reflectance changes. As a result, the spectral line width of the entire laser beam 21 output from the master oscillator 110 can be controlled.
- the master oscillator 110 may include a moving mechanism that can move the fine etalon 114.
- the moving mechanism may move the fine etalon 114 in the direction in which the reflectance of the portion arranged in the optical path of the fine etalon 114 changes.
- the moving stage 114a and the driving unit 114b may be included.
- the moving stage 114a may hold the fine etalon 114.
- the drive unit 114b may move the moving stage 114a in a direction in which the reflectance of the portion arranged in the optical path of the fine etalon 114 changes.
- the fine etalon 114 may be fixed to the moving stage 114a so that the reflectance gradually changes along the moving direction of the moving stage 114a.
- the fine etalon 114 may be disposed in a portion of the optical path having a different reflectance from the portion of the fine etalon 114 that has been disposed in the optical path before the movement.
- the control unit 430 may control the moving stage 114a via the drive unit 114b. By doing so, the control unit 430 can control the spectral line width of the solid-state laser device 10.
- the longitudinal mode interval of the laser light 21 can be adjusted by adjusting the resonator length L sol of the optical resonator formed by the high reflection mirror 111 and the output coupler 116. Further, the spectral line width of the laser light 21 can be adjusted by moving the fine etalon 114 and adjusting the reflectance of the portion through which the laser light is transmitted.
- FIG. 12 schematically shows a schematic configuration of the master oscillator 120 provided with the band narrowing element.
- the master oscillator 120 may include an output coupler 121, a titanium sapphire crystal 122 as a gain medium, a band narrowing unit 123, a beam splitter 125, and a pumping laser 126.
- the band narrowing unit 123 may function as a rear mirror of the optical resonator. In that case, the output coupler 121 and the band narrowing unit 123 may form an optical resonator.
- the master oscillator 120 may include a rear mirror of an optical resonator separately from the band narrowing unit 123.
- the titanium sapphire crystal 122 may be disposed on the optical path in the optical resonator formed by the output coupler 121 and the band narrowing unit 123.
- the surface inside the optical resonator of the output coupler 121 may be coated with a film that partially reflects light having a wavelength near 773.6 nm and highly transmits the excitation light 61 from the pumping laser 126.
- the opposite surface of the output coupler 121 may be coated with a film that highly transmits the excitation light 61.
- the output coupler 121 functions as an optical output terminal for outputting the laser light 21 and can take in the pumping light from the pumping laser 126 into the optical resonator.
- the beam splitter 125 may be disposed on the optical path of the laser light 21 output via the output coupler 121.
- the surface on the optical resonator side of the beam splitter 125 may be coated with a film that highly reflects the excitation light 61 from the pumping laser 126 and highly transmits light having a wavelength in the vicinity of 773.6 nm.
- the opposite surface of the beam splitter 125 may be coated with a film that highly transmits light with a wavelength in the vicinity of 773.6 nm (laser light 21). Accordingly, the beam splitter 125 can reflect the pumping light 61 from the pumping laser 126 to the output coupler 121 and output the laser light 21 output via the output coupler 121 from the master oscillator 120.
- the excitation light 61 that has entered the optical resonator via the output coupler 121 may be incident on the titanium sapphire crystal 122.
- the light input / output end face of the titanium sapphire crystal 122 may be Brewster cut.
- laser light may be emitted.
- the laser light emitted from the titanium sapphire crystal 122 may reciprocate in the optical resonator constituted by the output coupler 121 and the band narrowing unit 123. As a result, the laser beam passing through the titanium sapphire crystal 122 may be amplified.
- the band narrowing unit 123 can adjust the spectral line width of the entire laser beam in the optical resonator. Therefore, the master oscillator 120 may include a drive unit 124 that can change the spectral line width by the band narrowing unit 123.
- the control unit 430 may control the band narrowing unit 123 via the drive unit 124. By doing so, the control unit 430 can control the spectral line width of the solid-state laser device 10.
- FIG. 13 schematically shows a schematic configuration of the master oscillator 120A provided with the band narrowing unit 123A.
- the band narrowing unit 123A may include a beam expander 123a and a grating 123b.
- the beam expander 123a may be configured using one or more optical elements such as a prism and a collimator lens.
- the grating 123b may function as a rear mirror of the optical resonator.
- the grating 123b may be arranged in a Littrow arrangement with respect to the light emitted from the beam expander 123a.
- the grating 123b may be a blazed grating. In this case, the grating 123b may be set to be incident on the light emitted from the beam expander 123a at a blaze angle.
- the excitation light 61 output from the pumping laser 126 may enter the titanium sapphire crystal 122 via the beam splitter 125 and the output coupler 121.
- the titanium sapphire crystal 122 is excited and can oscillate between the output coupler 121 and the grating 123b.
- the laser beam in the optical resonator may be expanded by the beam expander 123a.
- the laser beam can be incident on the grating 123b at a predetermined incident angle.
- the grating 123b can narrow the spectrum of this laser beam.
- the bandwidth of the spectrum by the grating 123b can be changed by changing the beam expansion ratio of the beam expander 123a.
- the longitudinal mode interval can be determined by the resonator length L sol between the output coupler 121 and the grating 123b. Therefore, the intensity distribution in the longitudinal mode can be controlled by changing the beam expansion rate of the beam expander 123a.
- the beam expansion rate by the beam expander 123a may be changeable.
- the drive unit 124 may change the beam expansion rate of the beam expander 123a by operating the beam expander 123a.
- the driving unit 124 may include a turntable that can adjust the inclination of the prism with respect to the optical path in the resonator. In that case, the driving unit 124 can change the beam expansion ratio of the beam expander 123a by adjusting the inclination of the prism with respect to the optical path by rotating the turntable.
- the drive unit 124 can change the beam expansion rate of the beam expander 123a by adjusting the zoom magnification of the collimator lens.
- the control unit 430 may control the beam expander 123 a via the drive unit 124. By doing so, the control unit 430 can control the spectral line width of the solid-state laser device 10.
- the longitudinal mode interval of the laser light 21 can be adjusted by adjusting the resonator length L sol of the optical resonator formed by the output coupler 121 and the grating 123b. Further, the spectral line width of the laser light 21 can be adjusted by adjusting the beam expansion rate of the beam expander 123a.
- FIG. 14 shows a schematic configuration of a master oscillator 130 including a seed laser that outputs seed light.
- the master oscillator 130 may include a plurality of semiconductor lasers 132-1 to 132-n, a light path adjuster 133, and a seed laser control unit 131 as a plurality of seed lasers.
- Each of the semiconductor lasers 132-1 to 132-n may be a diode laser, for example.
- Each of the semiconductor lasers 132-1 to 132-n may oscillate in a single longitudinal mode or a multiple longitudinal mode.
- the seed laser control unit 131 is configured to combine each of the laser beams (laser beams 21) obtained by combining the longitudinal mode laser beams L 1-1 to L 1-n output from the plurality of semiconductor lasers 132-1 to 132-n.
- the oscillation wavelengths of the longitudinal mode laser beams L 1-1 to L 1-n oscillated by the semiconductor lasers 132-1 to 132-n so that the distribution of the longitudinal mode peaks is close to the spectrum SP shown in FIG.
- the output intensity may be controlled.
- the optical adjuster 133 includes a plurality of longitudinal modes having different wavelengths by matching the optical paths of the longitudinal mode laser beams L 1-1 to L 1-n output from the semiconductor lasers 132-1 to 132-n.
- the laser beam 21 may be output.
- an example of the optical path controller 133 shown in FIG. 14 will be described in detail with reference to the drawings. In the following description, the number of semiconductor lasers 132-1 to 132-n is assumed to be five for simplicity of explanation.
- FIG. 15 schematically shows a schematic configuration of the optical path adjuster 133A.
- the longitudinal mode laser beam L 1-1 output from the semiconductor laser 132-1 may be transmitted through the half mirror 1331, reflected by the high reflection mirror 1338, and reflected by the half mirror 1337. .
- the optical path of the longitudinal mode laser beam L 1-1 can coincide with the optical path of the laser beam 21.
- the longitudinal mode laser beam L 1-2 output from the semiconductor laser 132-2 is reflected by the high reflection mirror 1332, reflected by the half mirror 1331, reflected by the high reflection mirror 1338, and reflected by the half mirror 1337. Good. Thereby, the optical path of the longitudinal mode laser beam L1-2 can coincide with the optical path of the laser beam 21.
- Longitudinal mode laser beam L 1-3 outputted from the semiconductor laser 132-3 may be transmitted through the half mirror 1335 and 1337. As a result, the optical path of the longitudinal mode laser light L 1-3 can coincide with the optical path of the laser light 21.
- Longitudinal mode laser light L 1-4 output from the semiconductor laser 132-4 is reflected by the half mirrors 1334 and 1333, reflected by the high reflection mirror 1336, reflected by the half mirror 1335, and transmitted through the half mirror 1337. Also good. Thereby, the optical path of the longitudinal mode laser light L1-4 can coincide with the optical path of the laser light 21.
- the longitudinal mode laser beam L 1-5 output from the semiconductor laser 132-5 may be transmitted through the half mirror 1333, reflected by the high reflection mirror 1336, reflected by the half mirror 1335, and transmitted through the half mirror 1337. . As a result, the optical path of the longitudinal mode laser beam L 1-5 can coincide with the optical path of the laser beam 21.
- the optical path controller 133A that can match the optical paths of the plurality of longitudinal mode laser beams L 1-1 to L 1-n may be realized by combining a plurality of high reflection mirrors and half mirrors.
- Equation (4) m may be the order of the diffracted light that matches the optical path, and N may be the number of grooves (units / mm) per unit length of the grating 133b.
- the incident angle ⁇ is 0 °. Therefore, the term regarding the incident angle ⁇ is omitted.
- the diffracted lights L 1-1-2 , L 1-2-1 , L 1-3-0 , L 1-4 + 1 and L 1-5 + 2 having different orders are shown.
- diffracted beams L 1-1-2 , L 1-2-1 , L 1-3 of the different orders of the longitudinal mode laser beams L 1-1 to L 1-5 emitted from the grating 133b.
- ⁇ 0 , L 1-4 + 1 and L 1-5 + 2 can be emitted in different directions of diffraction angles ⁇ 1-1-2 , ⁇ 1-2-1 , ⁇ 1-4 + 1 and ⁇ 1-5 + 2 , respectively.
- the wavelengths of at least one longitudinal mode laser beam L 1-1 to L 1-5 may be different from the wavelengths of other longitudinal mode laser beams L 1-1 to L 1-5 , or all longitudinal mode laser beams L 1-1 to L 1-5 may have different wavelengths.
- the wavelengths of the mode laser beams L 1-1 to L 1-5 may be the same.
- the longitudinal angle laser beams L 1-1 to L 1-5 from the semiconductor lasers 132-1 to 132-5 are incident on the incident angles ⁇ 1 according to the respective wavelengths and the target order. It may be incident on the grating 133b at -1-2 to ⁇ 1-5 + 2 .
- optical path controller 133B described above may be effective when a plurality of solid-state lasers, for example, a titanium sapphire laser oscillator, may be used as a seed laser.
- FIG. 19 shows a schematic configuration of a master oscillator 140 including an optical modulator.
- the master oscillator 140 may include a seed laser 141, an optical modulator 142, and a drive unit 143.
- the seed laser 141 may be a semiconductor laser or a solid-state laser such as a titanium sapphire laser oscillator.
- the seed laser 141 may oscillate in a wavelength region (for example, a visible region) with good oscillation efficiency.
- the seed laser 141 may output seed light 21a including at least one longitudinal mode.
- the optical modulator 142 optically modulates the seed light 21a output from the seed laser 141, thereby generating laser light 21 including a plurality of longitudinal modes in which the distribution of the peak of each longitudinal mode is close to the spectrum SP. May be.
- the drive unit 143 may control the center wavelength and the spectral line width of the laser light 21 output from the optical modulator 142 by controlling the optical modulator 142.
- FIG. 19 an example of the optical modulator 142 shown in FIG. 19 will be described in detail with reference to the drawings.
- FIG. 20 shows a schematic configuration of a master oscillator 140A provided with the electro-optic element 142A as an optical modulator 142.
- FIG. 21 shows an example of the seed light 21a output from the seed laser 141 shown in FIG.
- FIG. 22 shows an example of the laser light 21 output from the electro-optical element 142A.
- the master oscillator 140 ⁇ / b> A may include an electro-optical element 142 ⁇ / b> A as the optical modulator 142.
- the electro-optic element 142A may generate the laser light 21 including a greater number of longitudinal modes than the seed light 21a by phase-modulating the seed light 21a output from the seed laser 141.
- the electro-optic element 142A may be an optical modulator that modulates the phase of transmitted light by an electro-optic effect of an electro-optic crystal such as lithium niobate (LiNbO 3 ).
- an electro-optic crystal such as lithium niobate (LiNbO 3 ).
- the electro-optic element 142A may be a Pockels cell.
- the refractive index of the electro-optic element 142A can be changed according to the strength of the electric field formed by the application of the voltage.
- the phase of the seed light 21a can be modulated.
- the frequency shift of the seed light 21a occurs, and the spectral line width can be expanded. Therefore, a voltage whose phase periodically changes may be applied to the electro-optical element 142A.
- the seed light 21 a output from the seed laser 141 can be converted into the laser light 21 including more longitudinal modes.
- the longitudinal mode interval of the laser beam 21 after conversion can be determined by the frequency of the applied voltage.
- the spectral line width of the entire laser beam 21 after conversion can be determined by the magnitude of the phase modulation, in other words, the magnitude of the applied voltage that determines the refractive index.
- a frequency modulator may be used.
- the seed laser 141 outputs a single longitudinal mode seed beam 21a.
- the wavelength corresponding to the center frequency ⁇ 0 of the seed light 21a may be 773.6 nm.
- a voltage changing at the frequency ⁇ 1 is applied to the electro-optical element 142A. This frequency ⁇ 1 may be about 150 MHz, for example.
- the seed light 21a incident on the electro-optical element 142A the vertical mode interval can be converted into a laser beam 21 of a multi-longitudinal mode of the omega 1.
- the drive unit 143 may apply a voltage to the electro-optical element 142A.
- the drive unit 143 may control the magnitude (amplitude) and frequency of the voltage applied to the electro-optic element 142A. Accordingly, the drive unit 143 can control the spectral line width and the longitudinal mode interval of the laser light 21 generated by the electro-optical element 142A.
- the longitudinal mode interval ⁇ of the laser beam 21 generated by the electro-optic element 142A. 1 should just be below (DELTA) omega gas .
- the frequency of the voltage applied to the electro-optic element 142A may be set to ⁇ gas or less.
- the laser beam 21 including a plurality of longitudinal modes can be generated from the seed beam 21a of the single longitudinal mode output from the seed laser 141. Therefore, restrictions on the resonator length required for the seed laser 141 can be reduced.
- FIG. 23 shows a schematic configuration of a master oscillator 140B provided with photoacoustic elements 142B and 142C as an optical modulator 142.
- FIG. 24 shows an example of the seed light 21a output from the seed laser 141 shown in FIG.
- FIG. 25 shows an example of the laser beam 21b output from the photoacoustic element 142B.
- FIG. 26 shows an example of the laser beam 21 output from the photoacoustic element 142C.
- the master oscillator 140B may include two photoacoustic elements 142B and 142C as the optical modulator 142.
- the photoacoustic element 142B may generate laser light 21b including a greater number of longitudinal modes than the seed light 21a by diffracting the seed light 21a output from the seed laser 141.
- the photoacoustic element 142C may generate the laser light 21 including a greater number of longitudinal modes than the laser light 21b by diffracting the laser light 21b output from the photoacoustic element 142B.
- the photoacoustic elements 142B and 142C may be optical modulators that modulate the intensity of transmitted light by an acoustooptic effect of an acoustooptic crystal such as LiNbO 3 (lithium niobate).
- an acoustic wave such as an ultrasonic wave is input to the acoustooptic crystal
- a coarse wave diffraction grating can be generated in the crystal. Therefore, when laser light is incident on a photoacoustic element to which an acoustic wave is input, the laser light passing through the acousto-optic crystal can be diffracted by the Raman-Nurs effect.
- the optical axis of the laser device in accordance with the optical path of the laser light when the acoustic wave is input to the acousto-optic crystal and when it is not input, the output laser light is input using non-input / output of the acoustic wave.
- the intensity can be changed.
- the degree of modulation can be set using the diffraction efficiency.
- the modulation frequency can be set using the on / off period of the acoustic wave.
- the diffraction efficiency of the photoacoustic element 142B may be approximately 50%, and the diffraction efficiency of the photoacoustic element 142C may be approximately 100%.
- the longitudinal mode spacing of the laser beam 21 of a multi-longitudinal-mode finally obtained may be 2 [omega 1.
- the longitudinal mode interval 2 ⁇ 1 may satisfy the longitudinal mode interval ⁇ gas or less.
- 2 ⁇ 1 ⁇ gas may be set.
- the seed laser 141 outputs a single longitudinal mode seed beam 21a.
- the wavelength corresponding to the center frequency ⁇ 0 of the seed light 21a may be 773.6 nm.
- the pulse width may be 10 to 20 ns. Therefore, the photoacoustic element 142B may give the seed light 21a intensity modulation with a diffraction efficiency of 50% and a modulation frequency of 4 ⁇ 1 (for example, 300 MHz).
- the seed light 21a can be converted into multi-longitudinal mode laser light 21b having a longitudinal mode interval of 4 ⁇ 1 , a spectral width of 8 ⁇ 1 , and three longitudinal modes.
- the light modulation at that time can be expressed by the following equation (5).
- the multi-longitudinal mode laser beam 21b output from the photoacoustic element 142B may be input to the photoacoustic element 142C.
- the photoacoustic element 142C may give the laser beam 21b intensity modulation with a diffraction efficiency of 100% and a modulation frequency of ⁇ 1 (for example, 75 MHz).
- ⁇ 1 for example, 75 MHz
- the laser beam 21b is converted into a multi-longitudinal mode laser beam 21 having a longitudinal mode interval of 2 ⁇ 1 (for example, 150 MHz), a spectral width of 10 ⁇ 1 , and six longitudinal modes. obtain.
- the light modulation at that time can be expressed by the following equation (6).
- the laser beam 21 including a plurality of longitudinal modes can be generated from the seed beam 21a of the single longitudinal mode output from the seed laser 141. Therefore, restrictions on the resonator length required for the seed laser 141 can be reduced.
- the amplifier 200 may be various amplifiers such as a power oscillator, a power amplifier, and a regenerative amplifier.
- the amplifier 200 may be a single amplifier or may include a plurality of amplifiers.
- specific examples of the amplifier 200 will be described with some examples. Note that although the master oscillator 100 is cited as the master oscillator, the other master oscillators described above may be used. Further, when the master oscillator 100 can output the laser beam 21 with sufficient intensity, the amplifier 200 may be omitted.
- FIG. 27 schematically shows a schematic configuration of an amplifier 200 of a Fabry-Perot type power oscillator.
- the amplifier 200 may include a high reflection mirror 202, an output coupler 204, a titanium sapphire crystal 203 as a gain medium, a high reflection mirror 201, and a pumping laser 205.
- the pumping laser 205 may be a pumping laser common to the master oscillator 100.
- the high reflection mirror 202 and the output coupler 204 may form an optical resonator.
- the titanium sapphire crystal 203 may be disposed on the optical path in the optical resonator formed by the high reflection mirror 202 and the output coupler 204.
- the high reflection mirror 201 may guide the laser light 21 incident from the master oscillator 100 and the excitation light 61 incident from the pumping laser 205 into the optical resonator.
- the high reflection mirror 201 may reflect the laser beam 21 incident from the master oscillator 100 to the optical resonator.
- the high reflection mirror 201 may transmit the excitation light 61 incident from the pumping laser 205 to the optical resonator.
- One high reflection mirror 202 forming the optical resonator may transmit the laser light 21 and the excitation light 61. Thereby, the laser beam 21 and the excitation light 61 may be taken into the optical resonator.
- the high reflection mirror 202 may reflect the laser light emitted from the titanium sapphire crystal 203.
- the laser light 21 and the excitation light 61 incident on the optical resonator via the high reflection mirror 202 may be incident on the titanium sapphire crystal 203.
- the light input / output end face of the titanium sapphire crystal 203 may be Brewster cut.
- the laser light emitted from the titanium sapphire crystal 203 may reciprocate in the optical resonator composed of the high reflection mirror 202 and the output coupler 204. As a result, laser light pumped up from the titanium sapphire crystal 203 may be emitted.
- the laser beam emitted from the titanium sapphire crystal 203 may be output as the laser beam 22 via the output coupler 204.
- FIG. 28 schematically shows a schematic configuration of an amplifier 210 configured as a ring-type power oscillator.
- the amplifier 210 may include an input / output coupler 211, high reflection mirrors 212 to 214, a titanium sapphire crystal 215 as a gain medium, and a pumping laser 216.
- the pumping laser 216 may be a common pumping laser with the master oscillator 100.
- the input / output coupler 211 and the high reflection mirrors 212 to 214 may form an optical resonator including a ring-shaped (eight-shaped) optical path P.
- the titanium sapphire crystal 215 may be disposed on the optical path P in the optical resonator formed by the input / output coupler 211 and the high reflection mirrors 212 to 214.
- the input / output coupler 211 may transmit the laser light 21 from the master oscillator 100 and reflect the laser light from the titanium sapphire crystal 215, for example.
- the input / output coupler 211 may transmit the laser beam from the titanium sapphire crystal 215.
- the high reflection mirror 213 may transmit the excitation light 61 from the pumping laser 216 to the optical resonator side and reflect the laser light from the titanium sapphire crystal 215.
- the laser beam 21 taken into the optical resonator may travel on a ring-shaped (eight-shaped) optical path P formed by the input / output coupler 211 and the high reflection mirrors 212 to 214.
- the laser beam pumped up by the titanium sapphire crystal 215 while traveling through the optical path P may be output as the laser beam 22 via the input / output coupler 211.
- the laser beam 21 can be amplified more efficiently than when, for example, a Fabry-Perot laser is used.
- the input / output coupler 211 having a relatively low reflectivity at the incident end of the laser beam 21, it may be possible to suppress the light intensity lower limit value of the laser beam 21.
- FIG. 29 schematically shows a schematic configuration of the regenerative amplifier 220.
- the regenerative amplifier 220 includes high reflection mirrors 221 and 226, a Pockels cell 222, a titanium sapphire crystal 223 as a gain medium, a polarization beam splitter 224, a Pockels cell 225, a pumping laser 227, May be provided.
- the pumping laser 227 may be a pumping laser common to the master oscillator 100.
- the high reflection mirrors 221 and 226 may form an optical resonator.
- the Pockels cell 222, the titanium sapphire crystal 223, the polarization beam splitter 224, and the Pockels cell 225 may be disposed on the optical path in the optical resonator formed by the high reflection mirrors 221 and 226.
- the Pockels cells 222 and 225 may function as ⁇ / 4 plates, for example, during a period in which a voltage is applied.
- the S-polarized laser light 21 may be incident on the incident surface of the polarization beam splitter 224, for example.
- the laser beam 21 may first enter the polarization beam splitter 224 inclined by 45 ° with respect to the optical path of the optical resonator.
- the polarization beam splitter 224 may reflect S-polarized light and transmit P-polarized light to the incident surface.
- the laser beam 21 incident from the master oscillator 100 can be reflected by the polarization beam splitter 224 and introduced into the optical resonator.
- a voltage may be applied only to the Pockels cell 225.
- the laser beam 21 that has passed through the Pockels cell 225 twice before being reflected by the high reflection mirror 226 can be converted into a P-polarized laser beam with respect to the light incident surface of the polarization beam splitter 224.
- a voltage may be applied to the Pockels cell 225 only during a period in which the laser light 21 is introduced into the optical resonator. Subsequently, voltage application to the Pockels cell 225 may be stopped. Thereby, since the polarization state of the laser beam 21 in the optical resonator does not change, the laser beam 21 can be confined in the optical resonator.
- the confined laser beam 21 may reciprocate once or more in the optical resonator.
- the laser beam 21 reciprocating in the optical resonator may be regenerated and amplified by passing through the titanium sapphire crystal 223 a plurality of times. Thereafter, a voltage may be applied to the Pockels cell 222. As a result, the laser light 21 that has passed through the Pockels cell 222 twice before being reflected by the high reflection mirror 221 can be converted into S-polarized laser light 21 with respect to the light incident surface of the polarization beam splitter 224. As a result, the laser beam 21 can be reflected by the polarization beam splitter 224 and output as the laser beam 22.
- FIG. 30 schematically shows a schematic configuration of an amplifier 230 configured as a multipath type power amplifier.
- the amplifier 230 may include a plurality of high reflection mirrors 231 to 237, a titanium sapphire crystal 238 as a gain medium, and a pumping laser 239.
- the pumping laser 239 may be a pumping laser common to the master oscillator 100.
- the plurality of high reflection mirrors 231 to 237 may form a multipath in which the laser light 21 input from the master oscillator 100 passes through the titanium sapphire crystal 238 a plurality of times (in this example, four times).
- the excitation light 61 from the pumping laser 239 may enter the titanium sapphire crystal 238 via the high reflection mirror 237. That is, the high reflection mirror 237 may transmit the excitation light 61 and reflect the laser light from the titanium sapphire crystal 238. In that case, when passing through the titanium sapphire crystal 238 a plurality of times, the laser beam 21 can be multipass amplified.
- the laser light after multipath amplification may be output as laser light 22.
- FIG. 31 schematically illustrates a schematic configuration of a wavelength conversion unit 300 including two SHG crystals.
- the second harmonic generated in the second SHG crystal based on the second harmonic generated in the first SHG crystal is referred to as a fourth harmonic.
- the wavelength conversion unit 300 includes a condenser lens 301, a BBO crystal 302 that is a first SHG crystal, a collimator lens 303, high reflection mirrors 304 and 305, and a condenser lens 306.
- a KBBF crystal 307 which is a second SHG crystal, a collimator lens 308, and a high reflection mirror 309 may be provided.
- the laser beam 22 output from the amplifier 200 may be first focused on the BBO crystal 302 by the condenser lens 301.
- This laser beam 22 may be a fundamental wave with respect to harmonics.
- the center wavelength of the fundamental wave may be 772 nm.
- the spectral line width of the entire fundamental wave may be 1.2 pm.
- the BBO crystal 302 may emit a second harmonic light laser beam 23 a with respect to the incidence of the laser light 22.
- the laser beam 23a may have a center frequency of 2 ⁇ , a center wavelength of 386 nm, and a spectral line width of 0.6 pm, for example.
- the laser beam 23 a emitted from the BBO crystal 302 may be collimated by the collimator lens 303.
- the collimated laser beam 23 a may be incident on the condenser lens 306 via the high reflection mirrors 304 and 305.
- the condensing lens 306 may condense the incident laser beam 23 a on the KBBF crystal 307.
- the high reflection mirror 304 may reflect the laser beam (laser beam 23a) having a frequency of 2 ⁇ and transmit the laser beam (laser beam 22t) having a frequency of ⁇ . Thereby, only the laser beam 23 a having a frequency of 2 ⁇ can be guided to the KBBF crystal 307.
- the KBBF crystal 307 is considered to be suitable for wavelength conversion to vacuum ultraviolet light having a wavelength of about 193 nm.
- the KBBF crystal 307 may emit laser light 23 of second harmonic light (fourth harmonic light) having the fundamental wave as the incident upon the incidence of laser light 23a having a center frequency of 2 ⁇ .
- the laser beam 23 emitted from the KBBF crystal 307 may be collimated by the collimator lens 308.
- the collimated laser beam 23 may be incident on the high reflection mirror 309.
- the high reflection mirror 309 may transmit a laser beam (laser beam 23t) having a frequency of 2 ⁇ and reflect a laser beam (laser beam 23) having a center frequency of 4 ⁇ . As a result, the laser beam 23 having a center frequency of 4 ⁇ can be output from the wavelength conversion unit 300.
- FIG. 32 shows the laser beam 22 output from the amplifier 200 (or the laser beam 21 output from the master oscillator 100).
- FIG. 33 shows the second harmonic light (laser light 23a) output from the BBO crystal 302 with respect to the incidence of the laser light 22 shown in FIG. FIG.
- the horizontal axis represents the difference frequency with respect to the center frequency of each spectrum
- the vertical axis represents the light intensity of each spectrum.
- the longitudinal mode interval ⁇ of the laser beam 23 a can be 150 MHz, which is the same as that of the laser beam 22.
- the longitudinal mode interval ⁇ of the laser beam 23 may be 150 MHz, which is the same as the laser beams 22 and 23a.
- the BBO crystal 302 and the KBBF crystal 307 can generate the second harmonic light or the fourth harmonic light at the longitudinal mode interval ⁇ of the laser light 22 (or the laser light 21) as the fundamental wave. As a result, it is possible to generate the laser beam 20 that substantially approximates the desired spectrum SP.
- the spectrum shape required in semiconductor exposure may be variable depending on the exposure conditions.
- the spectrum (spectral shape) of the laser light 23 output from the wavelength conversion unit 300 can change according to the spectrum of the laser light 22 input to the wavelength conversion unit 300. Therefore, for example, when using the master oscillator 140B provided with the photoacoustic elements 142B and 142C shown in FIG. 23 as the optical modulator 142, the laser light 20 having a desired spectral shape can be output from the solid-state laser device 10. It is desirable to adjust the spectra of the laser beams 23a and 23 generated in the acoustic elements 142B and 142C. This intensity distribution can be controlled, for example, by setting intensity modulation applied to the laser light 22 or 23a in the photoacoustic elements 142B and 142C.
- FIG. 36 shows the fourth harmonic light (laser light 23) generated using the BBO crystal 302 and the KBBF crystal 307 with the laser light 22 shown in FIG. 35 as a fundamental wave.
- FIG. 38 shows fourth harmonic light (laser light 23) generated using the BBO crystal 302 and the KBBF crystal 307 with the laser light 22 shown in FIG. 37 as a fundamental wave.
- FIG. 40 shows fourth harmonic light (laser light 23) generated by using the BBO crystal 302 and the KBBF crystal 307 with the laser light 22 shown in FIG. 39 as a fundamental wave.
- the longitudinal mode interval ⁇ of the laser light 21 as the fundamental wave may be 150 MHz. Further, the number of longitudinal modes may be five. 35 to 40, the horizontal axis indicates the difference frequency from the center frequency of each spectrum, and the vertical axis indicates the light intensity of each spectrum. 35 to 40, the spectrum intensity is normalized so that the maximum value is 1.
- the detection unit 420 in the solid-state laser device 10 illustrated in FIG. 3 will be described. Note that although the master oscillator 100 is cited as the master oscillator, the other master oscillators described above may be used.
- the laser beam 23 output from the wavelength converter 300 may be branched by the beam splitter 410 as described with reference to FIG.
- the laser beam 23 that has passed through the beam splitter 410 may be output from the solid-state laser device 10 as, for example, the laser beam 20.
- the laser beam 24 reflected by the beam splitter 410 may be incident on the detection unit 420.
- the detection unit 420 can detect the spectral line width of the incident laser beam 24.
- an example of the detection unit 420 illustrated in FIG. 3 will be described with reference to the drawings.
- FIG. 41 schematically shows a schematic configuration of the detection unit 420.
- the detection unit 420 may include a diffusion plate 421, a monitor etalon 422, a condenser lens 423, and an image sensor 425 (or a photodiode array).
- the laser beam 24 branched by the beam splitter 410 may first enter the diffusion plate 421.
- the diffusion plate 421 may scatter the incident laser beam 24. This scattered light may be incident on the monitor etalon 422.
- the monitor etalon 422 may be an air gap etalon in which two mirrors each having a partially reflective film coated on the surface of a substrate that transmits the laser light 24 are bonded to each other at a predetermined interval. .
- the monitor etalon 422 may transmit light having a predetermined wavelength out of incident scattered light. This transmitted light may be incident on the condenser lens 423.
- the image sensor 425 may be disposed on the focal plane of the condenser lens 423.
- the transmitted light collected by the condenser lens 423 can cause the image sensor 425 to generate interference fringes.
- the image sensor 425 may detect the generated interference fringes.
- the square of the radius of the interference fringes can be proportional to the wavelength of the laser light 24. Therefore, the spectrum of the entire laser beam 24 can be detected from the detected interference fringes.
- the spectral line width may be obtained from the detected spectrum by an information processing device (not shown) or may be calculated by the control unit 430.
- a light shielding plate 424 may be provided between the condenser lens 423 and the image sensor 425. Thereby, stray light can be reduced and interference fringes can be detected with high accuracy.
- FIG. 42 schematically illustrates a schematic configuration of the detection unit 420A.
- the detection unit 420A may include a diffusion plate 421a, a condenser lens 422a, and a spectroscope 423a.
- the spectroscope 423a may include a concave mirror 425a, a grating 426a, a concave mirror 427a, and an image sensor (line sensor) 428a.
- the laser beam 24 branched by the beam splitter 410 may first enter the diffusion plate 421a.
- the diffuser plate 421a may scatter the incident laser beam 24. This scattered light may be incident on the condenser lens 422a.
- An entrance slit 424a of the spectroscope 423a may be disposed near the focal plane of the condenser lens 422a.
- the entrance slit 424a may be located slightly on the near side of the focal plane of the condenser lens 422a.
- the scattered light collected by the condenser lens 422a may be incident on the concave mirror 425a through the incident slit 424a.
- the concave mirror 425a may convert incident scattered light into parallel light and reflect it.
- This reflected light may be incident on the grating 426a.
- the grating 426a may diffract the incident parallel light.
- This diffracted light may be incident on the concave mirror 427a.
- the concave mirror 427a may reflect the incident diffracted light so as to collect it.
- An image sensor 428a may be disposed on the focal plane of the concave mirror 427a. In that case, the reflected light collected by the concave mirror 427a can be imaged on the image sensor 428a.
- the image sensor 428a may detect the light intensity distribution at each imaging position (channel).
- the imaging position of the reflected light can be proportional to the wavelength of the laser light 24. Therefore, the entire spectrum of the laser beam 24 can be detected from the detected imaging position.
- the spectral line width may be obtained from the detected spectrum by an information processing device (not shown) or may be calculated by the control unit 430.
- the spectral line width of the entire laser beam 24 may be obtained as a line width of a curve obtained by fitting a curve connecting light intensity peaks in each longitudinal mode.
- the spectral line width of the entire laser beam 24 may be obtained as a line width of this spectrum by detecting a blurred spectrum using the detection unit 420 having a relatively low resolution.
- the detection unit 420 may input the detected spectral line width to the control unit 430.
- the laser beam 23 output from the wavelength conversion unit 300 that is, the output of the solid-state laser device 10 is sampled, and the spectral line width thereof is detected by the detection unit 420.
- the present invention is not limited to this.
- the laser beam 21 output from the master oscillator 100 or the laser beam 22 output from the amplifier 200 may be sampled, and the spectral line width thereof may be detected by the detection unit 420.
- control unit 430 in the solid-state laser apparatus 10 illustrated in FIG. 3 will be described. Note that although the master oscillator 100 is cited as the master oscillator, the other master oscillators described above may be used.
- control unit 430 may perform feedback control of the master oscillator 100 based on the spectral line width detected by the detection unit 420. Specifically, the control unit 430 may transmit a control signal to the drive unit 101b of the master oscillator 100 so that the spectral line width detected by the detection unit 420 becomes a desired spectral line width. At that time, the control unit 430 may control the center frequency, the longitudinal mode interval, and the light intensity of each longitudinal mode laser beam L1 to Ln included in the laser beam 21 output from the master oscillator 100.
- the spectral purity E95 can be one of the indexes that affect the resolution of the lens of the exposure apparatus, for example.
- the spectral purity E95 required on the exposure apparatus side may be input to the control unit 430 from an external apparatus 50 such as an exposure apparatus controller or a host controller of the laser system 1.
- the control unit 430 may calculate the spectral purity E95 from the spectrum detected by the detection unit 420, and may compare the calculated spectral purity with the requested spectral purity E95. Further, the control unit 430 may perform feedback control of the master oscillator 100 so that the spectral purity of the pulsed laser light 21 becomes the required spectral purity E95 based on the comparison result.
- the amplifying device 80 shown in FIG. 2 will be described in detail with reference to the drawings.
- the amplifying device 80 may be various amplifying devices such as a power oscillator, a power amplifier, and a regenerative amplifier.
- the amplifying device 80 may be one amplifying device or may include a plurality of amplifying devices.
- the solid-state laser device the solid-state laser device 10 shown in FIG. 3 is cited, but other solid-state laser devices may be used.
- FIG. 44 schematically shows a schematic configuration of an amplifying apparatus 80 configured as a power oscillator.
- the amplification device 80 may include a rear mirror 81, a chamber 83, and an output coupler 88.
- the rear mirror 81 may be one resonator mirror of the optical resonator.
- the chamber 83 may include an amplification region that amplifies the laser light 20 that reciprocates in the optical resonator.
- the output coupler 88 may be the other resonator mirror of the optical resonator.
- the output coupler 88 may be an output end of the laser beam 40.
- the amplifying apparatus 80 may further include a slit 82 that adjusts the beam profile of the laser beam 20 that reciprocates in the optical resonator.
- Windows 84 and 87 may be provided in the chamber 83.
- the windows 84 and 87 may optically open the chamber 83 with respect to the laser beam 20 while maintaining the confidentiality of the chamber 83.
- a gaseous gain medium may be enclosed in this chamber 83.
- the gain medium may include at least one of, for example, Kr gas, Ar gas, F 2 gas, Ne gas, and Xe gas.
- a pair of discharge electrodes 85 and 86 may be provided in the chamber 83. Discharge electrodes 85 and 86 may be arranged so as to sandwich a region (amplification region) through which laser beam 20 passes.
- a pulsed high voltage may be applied between the discharge electrodes 85 and 86 from a power source (not shown).
- the high voltage may be applied between the discharge electrodes 85 and 86 in accordance with the timing at which the laser beam 20 passes through the amplification region.
- an amplification region including an activated gain medium may be formed between the discharge electrodes 85 and 86.
- the laser beam 20 can be amplified when passing through this amplification region. Note that the amplified laser beam 20 may be output from the output coupler 88 as the laser beam 40.
- the laser light 21 output from the master oscillator 100 can be wavelength-converted by the wavelength conversion unit 300.
- the laser beam 20 having a spectral line width that can suppress chromatic aberration and suppress speckle can be generated.
- a master oscillator that uses a solid material such as a titanium sapphire crystal or a semiconductor as a laser oscillation medium may have better oscillation efficiency than a general gas laser. Therefore, according to Embodiment 1, energy saving can be achieved.
- a master oscillator using a solid-state laser oscillation medium such as a titanium sapphire crystal or a semiconductor is generally smaller and simpler than a gas laser. For this reason, the entire laser system 1 can be reduced in size and simplified.
- the spectral line width of the laser light 23 after wavelength conversion can be detected, and the master oscillator 100 can be feedback-controlled based on the detection result.
- the spectral line width of the laser beam 20 having a spectrum close to the spectrum of the laser beam 40 actually used for exposure can be detected.
- the master oscillator 100 can be feedback controlled with higher accuracy and stability.
- a laser beam (ArF laser) having a center wavelength of 193.5 nm may be required as a laser beam for semiconductor exposure.
- the resonator length L EXC is about 1 m
- the spectral purity E95 is 0.3 pm
- the number of longitudinal modes contained in the laser light is 17. Therefore, a case where a laser beam having 17 longitudinal modes is generated using the laser system 1 according to the first embodiment will be described below.
- the longitudinal mode interval ⁇ (or ⁇ ) of laser light oscillated by a general solid-state laser is very wide compared to the longitudinal mode interval of laser light oscillated by a semiconductor laser, for example. Therefore, it may be difficult to include a desired number of longitudinal modes within a desired spectral line width.
- the resonator length L sol of the master oscillator 100 is 1 m, and the number of longitudinal modes of the laser light 21 (fundamental wave) is five. Further, the center wavelength of the laser beam 21 is set to 773.6 nm.
- the wavelength conversion unit 300 using the BBO crystal 302 and the KBBF crystal 307 can generate fourth harmonic light (laser light 23) having, for example, 17 longitudinal modes from the laser light 22 amplified by the amplifier 200.
- the center wavelength of the laser beam 23 can be 193.4 nm.
- the BBO crystal 302 of the wavelength converter 300 has a center wavelength of 386.8 nm and a longitudinal mode number of 9 from the laser light 22 (fundamental wave) having a center wavelength of 773.6 nm and a longitudinal mode number of 5.
- the second harmonic light (laser light 23a) of the book can be generated.
- the KBBF crystal 307 is composed of a second harmonic light (laser beam 23a) having a center wavelength of 386.8 nm and 9 longitudinal modes, and a fourth harmonic light (laser having a center wavelength of 193.4 nm and 17 longitudinal modes).
- Light 23 can be generated. According to the laser beam 23 having 17 longitudinal modes, chromatic aberration can be suppressed and speckle can be suppressed.
- FIG. 45 schematically shows a schematic configuration of the laser system 2 according to the second embodiment.
- the laser system 2 may include a solid-state laser device 10 and an amplifying device 80, similarly to the laser system 1 shown in FIG.
- the laser system 2 may further include a beam splitter 610, a detection unit 620, and a control unit 630.
- the beam splitter 610 may be disposed on the optical path of the laser light 40 output from the amplification device 80.
- the beam splitter 610 may branch the optical path of the laser light 40 into two.
- the laser beam 40 that has passed through the beam splitter 610 may be output to, for example, an exposure apparatus.
- the laser beam 40 reflected by the beam splitter 610 may enter the detection unit 620 as the laser beam 41.
- the detection unit 620 may be the same as the detection unit 420 in the first embodiment.
- the detection unit 620 may detect the spectral line width of the entire laser beam 41.
- the control unit 630 may perform feedback control on the master oscillator 100 of the solid-state laser device 10 based on the detected spectral line width. At this time, the control unit 630 may control the center frequency, the longitudinal mode interval, and the light intensity of each longitudinal mode L1 to Ln included in the laser light 21 output from the master oscillator 100. Further, the control unit 630 may perform feedback control of the master oscillator 100 in accordance with a request from the external apparatus 50 such as an exposure apparatus controller.
- the spectral purity E95 required on the exposure apparatus side may be input to the control unit 630 from an external apparatus 50 such as an exposure apparatus controller or a host controller of the laser system 2.
- the control unit 630 may calculate the spectral purity E95 from the spectrum detected by the detection unit 620, and may compare the calculated spectral purity with the requested spectral purity E95. Further, the control unit 630 may perform feedback control of the master oscillator 100 so that the spectral purity of the laser light 21 becomes the required spectral purity E95 based on the comparison result.
- the master oscillator 100 can be feedback controlled based on the spectral line width of the laser light 40 actually used for exposure. As a result, it is possible to generate the laser beam 40 that can satisfy the external request. Since other configurations, operations, and effects are the same as those of the first embodiment or the modification thereof, detailed description thereof is omitted here.
- FIG. 46 schematically shows a schematic configuration of a solid-state laser apparatus 10 ⁇ / b> A according to Modification 1 of the solid-state laser apparatus 10.
- the solid-state laser device 10A may further include a low-coherence unit 500 in addition to the same configuration as that of the solid-state laser device 10 shown in FIG.
- the low coherence unit 500 may be arranged at the subsequent stage of the wavelength conversion unit 300.
- the low coherence unit 500 may reduce the coherency of the incident laser beam 23. Thereby, the laser beam 25 which is hard to generate speckles can be generated.
- FIG. 47 schematically shows a schematic configuration of the low coherence reduction unit 500 shown in FIG.
- the low coherence reduction unit 500 may include a beam splitter 501 and concave high reflection mirrors 502 to 505.
- the beam splitter 501 may reflect a part of the laser beam 23 and transmit the other part.
- the concave high reflection mirrors 502 to 505 may form an optical path for transferring the optical image of the laser beam 23 reflected by the beam splitter 501 to the beam splitter 501 again.
- the optical path of the laser beam 23 s incident on the beam splitter 501 can coincide with the optical path of the laser beam 23 f transmitted through the beam splitter 501. As a result, a part of the incident laser beam 23 can be delayed. Thereby, the coherency of the laser beam 25 including the laser beams 23s and 23f can be reduced.
- the coherence reduction unit 500 is not limited to optical pulse stretching, and may be configured using other optical elements. For example, by using a random phase plate, the coherency of the laser beam can be reduced.
- the low coherence unit 500 may be provided before the wavelength conversion unit 300. In this case, the coherency of the laser beam can be reduced at a short wavelength stage where energy loss due to reflection is relatively small. Note that the arrangement order of the wavelength conversion unit 300 and the low coherence unit 500 is not limited to the above-described order.
- the low coherence reduction unit 500 is arranged on the optical path between the amplifier 200 and the wavelength conversion unit 300.
- the wavelength of the laser beam 21 output from the master oscillator 100 is ⁇ solid_mo
- the spectral width of the laser beam 21 is ⁇ solid_mo
- the optical path length of the resonator formed by the high reflection mirror 202 and the output coupler 204 of the amplifier 200 is set.
- L reso be the optical path length of the low coherence unit 500 as L ops .
- the coherent length L coh of the laser beam 25 after the reduction in coherence may satisfy the relationship of the following equation (8).
- FIG. 48 schematically shows a schematic configuration of a solid-state laser apparatus 10B according to Modification 2 of the solid-state laser apparatus 10.
- the solid-state laser device 10B may include a master oscillator 100B and a wavelength conversion unit 300B instead of the master oscillator 100 and the wavelength conversion unit 300 illustrated in FIG.
- Other configurations may be the same as those shown in FIG.
- the master oscillator 100B may be, for example, a solid-state laser or a semiconductor laser using a titanium sapphire crystal as a laser crystal.
- the master oscillator 100B may output multi-longitudinal mode laser light (fundamental wave) having a wavelength of 745.3 nm, for example.
- multi-longitudinal mode laser light (fundamental wave) having a wavelength of 745.3 nm, for example.
- Various mechanisms can be applied as the mechanism for generating the multi-longitudinal mode laser beam.
- the wavelength conversion unit 300B may include an LBO crystal 312 and a THG crystal 317.
- the master oscillator 100B may output a laser beam 21B having a center wavelength of 745.3 nm.
- the amplifying unit 200 may amplify the laser beam 21B and output the laser beam 22B.
- the THG crystal 317 may be a nonlinear optical crystal that can generate third harmonic light.
- the laser beam 23B may be output as the laser beam 20 from the solid-state laser device 10B.
- nonlinear optical crystals for the wavelength conversion unit, it is possible to generate multi-longitudinal mode laser light applicable not only to ArF lasers but also to KrF lasers and other lasers.
- various nonlinear optical crystals such as a CLBO crystal can be used in addition to the above-described BBO crystal, LBO crystal, and KBBF crystal.
- FIG. 49 schematically shows a schematic configuration of the laser system 3 according to the third embodiment.
- FIG. 50 schematically shows another cross-sectional configuration along the optical path of the amplifying apparatus 90 shown in FIG.
- an amplifying device 90 that is a power amplifier may be used instead of the power oscillator type amplifying device 80 shown in FIG.
- the laser system 3 may further include a shutter 98 that blocks the laser light 40 output from the amplification device 90.
- the amplifying device 90 may include high reflection mirrors 91a, 91b, 97a and 97b, an output coupler 91, and a chamber 92.
- High reflection mirrors 91a, 91b, 97a and 97b and output coupler 91 may form a multipath that passes through the amplification region in chamber 92 a plurality of times.
- the output coupler 91 may be a partial reflection mirror.
- the chamber 92 may be disposed on an optical path formed by the high reflection mirrors 91a, 91b, 97a and 97b and the output coupler 91.
- the amplifying apparatus 90 may further include a slit (not shown) that adjusts the beam profile of the laser light traveling inside.
- a gaseous gain medium may be enclosed in the chamber 92 so as to fill the amplification region.
- the gain medium may include at least one of, for example, Kr gas, Ar gas, F 2 gas, Ne gas, and Xe gas.
- the laser light 20 output from the solid-state laser device 10 may be incident on the amplification device 90 via the optical system 30A including the high reflection mirror 31 and the beam splitter 33.
- the incident laser light 20 may first be reflected by the high reflection mirrors 91 a and 91 b and then enter the chamber 92 through the window 93.
- the laser beam 20 incident on the chamber 92 may be amplified when passing through an amplification region between the two discharge electrodes 94 and 95 to which a voltage is applied.
- the amplified laser beam 20 may be emitted from the chamber 92 through the window 96.
- the emitted laser light 20 may be incident again into the chamber 92 through the window 96 by being reflected by the high reflection mirrors 97a and 97b. Thereafter, the laser beam 20 may be amplified again when passing through the amplification region in the chamber 92.
- the amplified laser beam 20 may be emitted from the chamber 92 through the window 93.
- a part of the laser light 20 that has passed through the amplification region in the chamber 92 twice may then be output as the laser light 40 via the output coupler 91. Further, the remaining laser light reflected by the output coupler 91 may be amplified again by traveling along the optical path formed by the high reflection mirrors 91a, 91b, 97a and 97b and the output coupler 91.
- the third embodiment it may be possible to perform multipath amplification of the laser light 20 in the amplification device 90. Therefore, the laser beam 40 with higher intensity can be generated.
- the output of the laser light 40 can be blocked using the shutter 98 arranged at the output stage of the amplification device 90.
- the shutter 98 may open / block the optical path of the laser light 40 under drive control by a control mechanism (not shown), for example. Since other configurations, operations, and effects are the same as those of the first and second embodiments or the modifications thereof, detailed description thereof is omitted here.
- the spectral line width can be suppressed to suppress chromatic aberration and speckle.
- a master oscillator that uses a solid as a laser oscillation medium such as a solid-state laser or a semiconductor laser has better oscillation efficiency than a general gas laser. Further, the configuration is simple and small. Therefore, by applying the master oscillator described above to MOPO and MOPA, a laser system that can reduce power consumption and save energy can be realized.
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Lasers (AREA)
Abstract
Description
1.概要
2.用語の説明
3.レーザシステム(実施の形態1)
3.1 スペクトル線幅をフィードバック制御する固体レーザ装置
3.1.1 マスタオシレータ
3.1.1.1 リットマンキャビティを備えたマスタオシレータ
3.1.1.2 波長フィルタを備えたマスタオシレータ(変形例1)
3.1.1.3 狭帯域化部を備えたマスタオシレータ(変形例2)
3.1.1.3.1 ビームエキスパンダおよびグレーティングを用いた狭帯域化部
3.1.1.4 シードレーザを備えたマスタオシレータ(変形例3)
3.1.1.4.1 複数のミラーを用いた光路調節器
3.1.1.4.2 グレーティングを用いた光路調節器
3.1.1.5 光変調器を備えたマスタオシレータ(変形例4)
3.1.1.5.1 電気光学素子を用いた光変調器
3.1.1.5.2 光音響素子を用いた光変調器
3.1.2 増幅器
3.1.2.1 ファブリペロー型パワーオシレータ
3.1.2.2 リング型パワーオシレータ(変形例1)
3.1.2.3 再生増幅器(変形例2)
3.1.2.4 マルチパス型パワー増幅器(変形例3)
3.1.3 波長変換部
3.1.3.1 BBO結晶およびKBBF結晶を用いた波長変換部
3.1.4 検出部
3.1.4.1 モニタエタロンを用いた検出部
3.1.4.2 ツェルニターナ型分光器を用いた検出部
3.1.5 制御部
3.2 増幅装置
3.2.1 パワーオシレータ
4.スペクトル線幅を全体フィードバック制御するレーザシステム(実施の形態2)
5.固体レーザ装置の変形例
5.1 低コヒーレンス化部を備えた固体レーザ装置(変形例1)
5.1.1 光学パルスストレッチを用いた低コヒーレンス化部
5.2 LBO結晶およびTHG結晶を用いた波長変換部を備えた固体レーザ装置(変形例2)
6.増幅装置にパワー増幅器を用いたレーザシステム(実施の形態3)
まず、以下で例示する実施の形態の概要を説明する。図1は、以下で例示する実施の形態の概要を説明するための図である。
マルチ縦モードとは、複数の縦モードを含むことをいう。複数の縦モードを含むレーザ光のスペクトル線幅とは、複数の縦モードを含んだレーザ光全体のスペクトルの線幅をいう。レーザ光は、パルス状のレーザ光であってもよいし、コンティニュアスなレーザ光であってもよい。増幅器および増幅装置には、パワーオシレータ、パワー増幅器、および再生増幅器などが含まれてもよい。パワーオシレータは、レーザ光を増幅するためのゲイン媒体と、光共振器とを含んでもよい。パワー増幅器は、レーザ光を増幅するためのゲイン媒体と、ゲイン媒体を通過するパスを形成する1つ以上の光学素子を含んでもよい。マスタオシレータには、マルチ縦モードのレーザ光を出力するレーザや、レーザ発振器などが含まれてもよい。
まず、本開示の実施の形態1によるレーザシステム1を、図面を参照して詳細に説明する。実施の形態1では、レーザシステム1として、出力レーザ光の中心波長が193nmのArFレーザを例に挙げる。ただし、これに限定されるものではない。KrFレーザやXeClレーザやXeFレーザなどのエキシマレーザなど、種々のレーザシステムをレーザシステム1として適用可能である。
まず、図2に示す固体レーザ装置10について、図面を用いて詳細に説明する。図3は、固体レーザ装置10の概略構成を模式的に示す。図3に示すように、固体レーザ装置10は、マスタオシレータ100と、増幅器200と、波長変換部300とを備えてもよい。マスタオシレータ100は、いわゆるシード光源であってもよい。マスタオシレータ100は、少なくとも1つの縦モードを含むレーザ光をレーザ光21として出力してもよい。レーザ光21が複数の縦モードを含む場合、レーザ光21に含まれる各縦モードの光強度のピークを結んだ曲線は、スペクトルSPに近似していてもよい。増幅器200は、レーザ光21を増幅し、レーザ光22として出力してもよい。波長変換部300は、マスタオシレータ100から出力されたレーザ光21(または増幅器200による増幅後のレーザ光22)の波長が増幅段である増幅装置80の増幅可能な波長領域にマッチングするように、レーザ光23を波長変換してもよい。たとえば、波長変換装置300は、レーザ光22に含まれる各縦モードを基本波として、それらの第4高調波光を生成してもよい。波長変換部300は、生成した第4高調波光を、レーザ光23として出力してもよい。
以下に、図3に示す固体レーザ装置10におけるマスタオシレータ100の具体例について、いくつか例を挙げて説明する。
まず、リットマンキャビティを備えたマスタオシレータ100を例に挙げて説明する。図4は、リットマンキャビティを備えたマスタオシレータ100の概略構成を模式的に示す。図4に示すように、マスタオシレータ100は、高反射ミラー101と、ゲイン媒体としてのチタンサファイア結晶102と、グレーティング103と、高反射ミラー104と、出力カプラ105と、ポンピングレーザ106とを備えてもよい。高反射ミラー101および出力カプラ105は、光共振器を構成してもよい。チタンサファイア結晶102およびグレーティング103は、高反射ミラー101および出力カプラ105が形成する光共振器内の光路上に配置されてもよい。高反射ミラー104は、グレーティング103で回折されたレーザ光を反射してグレーティング103に戻してもよい。この高反射ミラー104は、反射面がグレーティング103の分散方向に対して曲率を変化させることができるディフォーマブルミラーであってもよい。この際、高反射ミラー101および104は、高反射ミラー101および出力カプラ105が構成する光共振器とは別の光共振器を形成してもよい。ただし、高反射ミラー101から高反射ミラー104までの共振器長Lsol1と、高反射ミラー101から出力カプラ105までの共振器長Lsol2とは、等しくてもよい。
つぎに、マスタオシレータの変形例1を、図面を参照して詳細に説明する。図5は、波長フィルタを備えたマスタオシレータ110の概略構成を模式的に示す。図5に示すように、マスタオシレータ110は、高反射ミラー111と、ゲイン媒体としてのチタンサファイア結晶112と、コースエタロン113と、ファインエタロン114と、複屈折フィルタ115と、出力カプラ116と、ポンピングレーザ117とを備えてもよい。高反射ミラー111と出力カプラ116とは、光共振器を構成してもよい。チタンサファイア結晶112、コースエタロン113、ファインエタロン114、および複屈折フィルタ115は、高反射ミラー111および出力カプラ116が形成する光共振器内の光路上に配置されてもよい。また、コースエタロン113と、ファインエタロン114と、複屈折フィルタ115は、狭帯域化部118を構成してもよい。
FSR=λ2/(2nd) ・・・(2)
FWHM=FSR/F ・・・(3)
つぎに、マスタオシレータの変形例2を、図面を参照して詳細に説明する。図12は、狭帯域化素子を備えたマスタオシレータ120の概略構成を模式的に示す。図12に示すように、マスタオシレータ120は、出力カプラ121と、ゲイン媒体としてのチタンサファイア結晶122と、狭帯域化部123と、ビームスプリッタ125と、ポンピングレーザ126とを備えてもよい。狭帯域化部123は、光共振器のリアミラーとして機能してもよい。その場合、出力カプラ121と狭帯域化部123とは、光共振器を形成してもよい。もしくは、マスタオシレータ120は、狭帯域化部123とは別に、光共振器のリアミラーを備えてもよい。チタンサファイア結晶122は、出力カプラ121および狭帯域化部123が形成する光共振器内の光路上に配置されてもよい。
ここで、図12に示す狭帯域化部123の一例を、図面を用いて詳細に説明する。図13は、狭帯域化部123Aを備えたマスタオシレータ120Aの概略構成を模式的に示す。図13に示すように、狭帯域化部123Aは、ビームエキスパンダ123aと、グレーティング123bとを備えてもよい。ビームエキスパンダ123aは、たとえばプリズムやコリメータレンズ等の1つ以上の光学素子を用いて構成されてもよい。グレーティング123bは、光共振器のリアミラーとして機能してもよい。グレーティング123bは、ビームエキスパンダ123aからの出射光に対してリトロー配置されていてもよい。グレーティング123bは、ブレーズドグレーティングであってもよい。この場合、グレーティング123bは、ビームエキスパンダ123aからの出射光に対してブレーズ角の角度で入射するように設定されてもよい。
つぎに、マスタオシレータの変形例3を、図面を参照して詳細に説明する。図14は、シード光を出力するシードレーザを備えたマスタオシレータ130の概略構成を示す。図14に示すように、マスタオシレータ130は、複数のシードレーザとして複数の半導体レーザ132-1~132-nと、光路調節器133と、シードレーザ制御部131とを備えてもよい。
まず、複数のミラーを用いた光路調節器133Aを、図面を用いて詳細に説明する。図15は、光路調節器133Aの概略構成を模式的に示す。図15に示す構成において、半導体レーザ132-1から出力された縦モードレーザ光L1-1は、ハーフミラー1331を透過し、高反射ミラー1338で反射し、ハーフミラー1337で反射してもよい。これにより、縦モードレーザ光L1-1の光路がレーザ光21の光路に一致し得る。半導体レーザ132-2から出力された縦モードレーザ光L1-2は、高反射ミラー1332で反射し、ハーフミラー1331で反射し、高反射ミラー1338で反射し、ハーフミラー1337で反射してもよい。これにより、縦モードレーザ光L1-2の光路がレーザ光21の光路に一致し得る。半導体レーザ132-3から出力された縦モードレーザ光L1-3は、ハーフミラー1335および1337を透過してもよい。これにより、縦モードレーザ光L1-3の光路がレーザ光21の光路に一致し得る。半導体レーザ132-4から出力された縦モードレーザ光L1-4は、ハーフミラー1334および1333で反射し、高反射ミラー1336で反射し、ハーフミラー1335で反射し、ハーフミラー1337を透過してもよい。これにより、縦モードレーザ光L1-4の光路がレーザ光21の光路に一致し得る。半導体レーザ132-5から出力された縦モードレーザ光L1-5は、ハーフミラー1333を透過し、高反射ミラー1336で反射し、ハーフミラー1335で反射し、ハーフミラー1337を透過してもよい。これにより、縦モードレーザ光L1-5の光路がレーザ光21の光路に一致し得る。
つぎに、グレーティング133bを用いた光路調節器133Bを、図面を用いて詳細に説明する。図16は、透過型のグレーティング133bに入射角β=0°で入射したレーザ光Lに対する±m次回折光を模式的に示す。図16に示すように、グレーティング133bは、それが持つ波長選択性(分散)に基づいて、入射角β=0°で入射したレーザ光Lの±m次回折光L±mを、レーザ光Lの波長λに依存した回折角α-m及びα+mで回折し得る。その際、回折角α±mと波長λとの関係は、以下の式(4)を満足し得る。なお、式(4)において、mは光路を一致させる回折光の次数、Nはグレーティング133bの単位長さあたりの溝本数(本/mm)であってよい。ただし、式(4)において、入射角βは0°である。そのため、入射角βに関する項は省略されている。
つぎに、マスタオシレータの変形例4を、図面を参照して詳細に説明する。図19は、光変調器を備えたマスタオシレータ140の概略構成を示す。図19に示すように、マスタオシレータ140は、シードレーザ141と、光変調器142と、駆動部143とを備えてもよい。シードレーザ141は、半導体レーザであってもよいし、チタンサファイアレーザ発振器のような固体レーザであってもよい。シードレーザ141は、発振効率の良い波長領域(例えば、可視域)で発振してもよい。シードレーザ141は、少なくとも1つの縦モードを含むシード光21aを出力すればよい。
まず、電気光学素子(EO)142Aを用いた光変調器142を、図面を用いて詳細に説明する。図20は、電気光学素子142Aを光変調器142として備えたマスタオシレータ140Aの概略構成を示す。図21は、図20に示すシードレーザ141から出力されたシード光21aの一例を示す。図22は、電気光学素子142Aから出力されたレーザ光21の一例を示す。
つぎに、光音響素子(AO)を用いた光変調器142を、図面を用いて詳細に説明する。図23は、光音響素子142Bおよび142Cを光変調器142として備えたマスタオシレータ140Bの概略構成を示す。図24は、図23に示すシードレーザ141から出力されたシード光21aの一例を示す。図25は、光音響素子142Bから出力されたレーザ光21bの一例を示す。図26は、光音響素子142Cから出力されたレーザ光21の一例を示す。
つぎに、図3に示す固体レーザ装置10における増幅器200について説明する。増幅器200は、パワーオシレータやパワー増幅器や再生増幅器など、種々の増幅器であってよい。また、増幅器200は、1つの増幅器であってもよいし、複数の増幅器を含んでいてもよい。以下に、増幅器200の具体例について、いくつか例を挙げて説明する。なお、マスタオシレータとしては、マスタオシレータ100を引用するが、上述した他のマスタオシレータを用いてもよい。また、マスタオシレータ100が十分な強度のレーザ光21を出力可能な場合、増幅器200は省略されてもよい。
まず、ファブリペロー型のパワーオシレータを増幅器200として用いた場合を例に挙げて説明する。図27は、ファブリペロー型パワーオシレータの増幅器200の概略構成を模式的に示す。図27に示すように、増幅器200は、高反射ミラー202と、出力カプラ204と、ゲイン媒体としてのチタンサファイア結晶203と、高反射ミラー201と、ポンピングレーザ205とを備えてもよい。ポンピングレーザ205は、マスタオシレータ100と共通のポンピングレーザであってもよい。
つぎに、増幅器200の変形例1を、図面を参照して詳細に説明する。図28は、リング型のパワーオシレータとして構成された増幅器210の概略構成を模式的に示す。図28に示すように、増幅器210は、入出力カプラ211と、高反射ミラー212~214と、ゲイン媒体としてのチタンサファイア結晶215と、ポンピングレーザ216とを備えてもよい。ポンピングレーザ216は、マスタオシレータ100と共通のポンピングレーザであってもよい。
つぎに、増幅器200の変形例2を、図面を参照して詳細に説明する。増幅器200の変形例2では、増幅器200として再生増幅器220を用いてもよい。図29は、再生増幅器220の概略構成を模式的に示す。図29に示すように、再生増幅器220は、高反射ミラー221および226と、ポッケルスセル222と、ゲイン媒体としてのチタンサファイア結晶223と、偏光ビームスプリッタ224と、ポッケルスセル225と、ポンピングレーザ227とを備えてもよい。ポンピングレーザ227は、マスタオシレータ100と共通のポンピングレーザであってもよい。
つぎに、増幅器200の変形例3を、図面を参照して詳細に説明する。図30は、マルチパス型のパワー増幅器として構成された増幅器230の概略構成を模式的に示す。図30に示すように、増幅器230は、複数の高反射ミラー231~237と、ゲイン媒体としてのチタンサファイア結晶238と、ポンピングレーザ239とを備えてもよい。ポンピングレーザ239は、マスタオシレータ100と共通のポンピングレーザであってもよい。
つぎに、図3に示す固体レーザ装置10における波長変換部300について、例を挙げて説明する。なお、マスタオシレータとしては、マスタオシレータ100を引用するが、上述した他のマスタオシレータを用いてもよい。
図31は、2つのSHG結晶を備えた波長変換部300の概略構成を模式的に示す。なお、以下では、1つ目のSHG結晶で発生した第2高調波に基づいて2つ目のSHG結晶で発生した第2高調波を、第4高調波という。
つぎに、図3に示す固体レーザ装置10における検出部420について説明する。なお、マスタオシレータとしては、マスタオシレータ100を引用するが、上述した他のマスタオシレータを用いてもよい。
まず、モニタエタロンを用いた検出部420を、図面を用いて詳細に説明する。図41は、検出部420の概略構成を模式的に示す。図41に示すように、検出部420は、拡散板421と、モニタエタロン422と、集光レンズ423と、イメージセンサ425(またはフォトダイオードアレイでもよい)とを備えてもよい。
つぎに、ツェルニターナ型分光器を用いた検出部420Aを、図面を用いて詳細に説明する。図42は、検出部420Aの概略構成を模式的に示す。図42に示すように、検出部420Aは、拡散板421aと、集光レンズ422aと、分光器423aとを備えてもよい。分光器423aは、凹面ミラー425aと、グレーティング426aと、凹面ミラー427aと、イメージセンサ(ラインセンサ)428aとを備えてもよい。
つぎに、図3に示す固体レーザ装置10における制御部430について説明する。なお、マスタオシレータとしては、マスタオシレータ100を引用するが、上述した他のマスタオシレータを用いてもよい。
J=Sb/Sa ・・・(7)
つぎに、図2に示す増幅装置80について、図面を用いて詳細に説明する。増幅装置80は、パワーオシレータやパワー増幅器や再生増幅器など、種々の増幅装置であってよい。また、増幅装置80は、1つの増幅装置であってもよいし、複数の増幅装置を含んでいてもよい。なお、固体レーザ装置としては、図3に示す固体レーザ装置10を引用するが、他の固体レーザ装置であってもよい。
図44は、パワーオシレータとして構成された増幅装置80の概略構成を模式的に示す。図44に示すように、増幅装置80は、リアミラー81と、チャンバ83と、出力カプラ88とを備えてもよい。リアミラー81は、光共振器の一方の共振器ミラーであってもよい。チャンバ83は、光共振器内を往復するレーザ光20を増幅する増幅領域を備えてもよい。出力カプラ88は、光共振器の他方の共振器ミラーであってもよい。この出力カプラ88は、レーザ光40の出力端であってもよい。増幅装置80は、光共振器内を往復するレーザ光20のビームプロファイルを調整するスリット82をさらに備えてもよい。チャンバ83には、ウィンドウ84および87が設けられてもよい。ウィンドウ84および87は、チャンバ83の機密性を保持しつつ、チャンバ83内をレーザ光20に対して光学的に開放してもよい。このチャンバ83内には、ガス状のゲイン媒体が封入されていてもよい。ゲイン媒体は、例えばKrガス、Arガス、F2ガス、Neガス、およびXeガスのうち少なくとも1つを含んでいてもよい。さらに、チャンバ83内には、一対の放電電極85および86が設けられてもよい。放電電極85および86は、レーザ光20が通過する領域(増幅領域)を挟むように配置されていてもよい。放電電極85および86間には、不図示の電源からパルス状の高電圧が印加されてもよい。高電圧は、レーザ光20が増幅領域を通過するタイミングに合わせて、放電電極85および86間に印可されてもよい。放電電極85および86間に高電圧が印加されると、放電電極85および86間に、活性化されたゲイン媒体を含む増幅領域が形成され得る。レーザ光20は、この増幅領域を通過する際に増幅され得る。なお、増幅後のレーザ光20は、レーザ光40として出力カプラ88から出力されてもよい。
つぎに、本開示の実施の形態2によるレーザシステム2を、図面を用いて詳細に説明する。図45は、実施の形態2によるレーザシステム2の概略構成を模式的に示す。図45に示すように、レーザシステム2は、図1に示すレーザシステム1と同様に、固体レーザ装置10と、増幅装置80とを備えてもよい。また、レーザシステム2は、ビームスプリッタ610と、検出部620と、制御部630とをさらに備えてもよい。ビームスプリッタ610は、増幅装置80から出力されたレーザ光40の光路上に配置されてもよい。ビームスプリッタ610は、レーザ光40の光路を2つに分岐してもよい。ビームスプリッタ610を透過したレーザ光40は、たとえば露光装置等へ出力されてもよい。ビームスプリッタ610で反射したレーザ光40は、レーザ光41として検出部620に入射してもよい。
つぎに、上述した固体レーザ装置10の他の形態を、図面を用いて詳細に説明する。
まず、固体レーザ装置10の変形例1を、図面を用いて詳細に説明する。図46は、固体レーザ装置10の変形例1による固体レーザ装置10Aの概略構成を模式的に示す。
ここで、光学パルスストレッチを用いた低コヒーレンス化部500について、図面を用いて詳細に説明する。図47は、図46に示す低コヒーレンス化部500の概略構成を模式的に示す。
つぎに、固体レーザ装置10の変形例2を、図面を用いて詳細に説明する。図48は、固体レーザ装置10の変形例2による固体レーザ装置10Bの概略構成を模式的に示す。
つぎに、本開示の実施の形態3によるレーザシステム3を、図面を用いて詳細に説明する。図49は、実施の形態3によるレーザシステム3の概略構成を模式的に示す。図50は、図49に示す増幅装置90の光路に沿う他の断面構成を模式的に示す。
Claims (21)
- 出力するレーザ光のスペクトル線幅を変更可能であり、少なくとも1つの縦モードを含むレーザ光を出力するマスタオシレータと、
前記マスタオシレータに対して下流側の光路上に配置された少なくとも1つの増幅器と、
前記増幅器に対して下流側の光路上に配置された波長変換部と、
前記レーザ光のスペクトルを検出する検出部と、
前記検出部の検出結果に基づいて前記マスタオシレータから出力される前記レーザ光のスペクトル線幅を制御する制御部と、
を備える固体レーザ装置。 - 前記マスタオシレータは、
光共振器と、
前記光共振器中に配置されたゲイン媒体と、
前記光共振器中に配置され、前記スペクトル線幅を変更可能な狭帯域化部と、
前記狭帯域化部を駆動する駆動部と、
を備え、
前記制御部は、前記駆動部を制御することで前記スペクトル線幅を制御する、請求項1記載の固体レーザ装置。 - 前記ゲイン媒体は、チタンサファイア結晶を含む、請求項2記載の固体レーザ装置。
- 前記狭帯域化部は、複屈折フィルタ、エタロン、および回折格子のうち少なくとも1つを含む、請求項2記載の固体レーザ装置。
- 前記狭帯域化部は、前記レーザ光の入射面および出射面の少なくとも一方に反射膜がコーティングされたエタロンを備え、
前記エタロンは、前記レーザ光の光路と異なる方向に移動可能に配置され、
前記反射膜の反射率は、前記入射面または前記出射面の位置に依存して変化し、
前記制御部は、前記駆動部を介して前記エタロンの前記レーザ光の光路に対する位置を制御する、
請求項2記載の固体レーザ装置。 - 前記マスタオシレータは、
少なくとも1つの縦モードを含むシード光を出力するシードレーザと、
前記シードレーザに対して下流側の光路上に配置された光変調器と、
前記光変調器を駆動する駆動部と、
を備え、
前記制御部は、前記駆動部を制御することで前記スペクトル線幅を制御する、請求項1記載の固体レーザ装置。 - 前記光変調器は、電気光学素子を含む、請求項6記載の固体レーザ装置。
- 前記光変調器は、光音響素子を含む、請求項6記載の固体レーザ装置。
- 前記マスタオシレータは、
少なくとも1つの縦モードを含むシード光をそれぞれ出力する複数のシードレーザと、
前記複数のシードレーザから出力されたシード光の光路を実質的に一致させる光路調節器と、
前記シードレーザを制御するシードレーザ制御部と、
を含み、
前記複数のシードレーザのうち少なくとも1つは、他のシードレーザと異なる中心波長の縦モードを含むシード光を出力し、
前記制御部は、前記シードレーザ制御部を制御することで前記スペクトル線幅を制御する、請求項1記載の固体レーザ装置。 - 前記シードレーザ制御部は、前記シードレーザの出力強度を制御する、請求項9記載の固体レーザ装置。
- 前記シードレーザ制御部は、前記シードレーザの発振波長を制御する、請求項9記載の固体レーザ装置。
- 前記シードレーザは、半導体レーザである、請求項9記載の固体レーザ装置。
- 前記増幅器は、ゲイン媒体としてチタンサファイア結晶を含む、請求項1記載の固体レーザ装置。
- 前記増幅器は、光共振器と、該光共振器中に配置されたゲイン媒体とを含む、請求項1記載の固体レーザ装置。
- 前記波長変換部は、前記マスタオシレータから出力された前記レーザ光を当該レーザ光の高次高調波光に変換する少なくとも1つの非線形光学結晶を含む、請求項1記載の固体レーザ装置。
- 前記少なくとも1つの非線形光学結晶は、BBO結晶、LBO結晶、CLBO結晶、KBBF結晶のうち少なくとも1つを含む、請求項15記載の固体レーザ装置。
- 請求項1~16のいずれか一つに記載の固体レーザ装置と、
前記固体レーザ装置に対して下流側の光路上に配置された少なくとも1つの増幅装置と、
を備える、レーザシステム。 - 前記検出部は、前記少なくとも1つの増幅装置に対して下流側の光路上に配置されている、請求項17記載のレーザシステム。
- 前記増幅装置は、ゲイン媒体を含む、請求項17記載のレーザシステム。
- 前記増幅装置は、前記ゲイン媒体としてKrガス、Arガス、F2ガス、Neガス、およびXeガスのうち少なくとも1つを含む、請求項19記載のレーザシステム。
- 前記増幅装置は、光共振器と、該光共振器中に配置されたゲイン媒体とを含む、請求項17記載のレーザシステム。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012517254A JP5914329B2 (ja) | 2010-05-24 | 2011-05-23 | 固体レーザ装置およびレーザシステム |
US13/671,657 US8625645B2 (en) | 2010-05-24 | 2012-11-08 | Solid-state laser apparatus and laser system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010118845 | 2010-05-24 | ||
JP2010-118845 | 2010-05-24 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/671,657 Continuation US8625645B2 (en) | 2010-05-24 | 2012-11-08 | Solid-state laser apparatus and laser system |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011148895A1 true WO2011148895A1 (ja) | 2011-12-01 |
Family
ID=45003885
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/061754 WO2011148895A1 (ja) | 2010-05-24 | 2011-05-23 | 固体レーザ装置およびレーザシステム |
Country Status (3)
Country | Link |
---|---|
US (1) | US8625645B2 (ja) |
JP (1) | JP5914329B2 (ja) |
WO (1) | WO2011148895A1 (ja) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015149478A (ja) * | 2014-02-05 | 2015-08-20 | ▲ホア▼▲ウェイ▼技術有限公司 | 光学レーザー装置及び当該装置においてレーザー発振モードを生成する方法 |
WO2016142996A1 (ja) * | 2015-03-06 | 2016-09-15 | ギガフォトン株式会社 | 固体レーザシステム、及び露光装置用レーザ装置 |
JP2018010123A (ja) * | 2016-07-13 | 2018-01-18 | 株式会社ディスコ | 波長変換装置 |
KR20190087855A (ko) * | 2018-01-17 | 2019-07-25 | 국방과학연구소 | 광 출력 장치 및 그 방법. |
JP2021114622A (ja) * | 2017-01-16 | 2021-08-05 | サイマー リミテッド ライアビリティ カンパニー | エキシマ光源におけるスペックルの低減 |
JPWO2020084685A1 (ja) * | 2018-10-23 | 2021-09-09 | ギガフォトン株式会社 | レーザシステム、及び電子デバイスの製造方法 |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8873596B2 (en) | 2011-07-22 | 2014-10-28 | Kla-Tencor Corporation | Laser with high quality, stable output beam, and long life high conversion efficiency non-linear crystal |
JP2013178462A (ja) * | 2012-02-08 | 2013-09-09 | Gigaphoton Inc | 波長変換器、波長変換装置、固体レーザ装置およびレーザシステム |
US9042006B2 (en) | 2012-09-11 | 2015-05-26 | Kla-Tencor Corporation | Solid state illumination source and inspection system |
US8929406B2 (en) | 2013-01-24 | 2015-01-06 | Kla-Tencor Corporation | 193NM laser and inspection system |
US9529182B2 (en) | 2013-02-13 | 2016-12-27 | KLA—Tencor Corporation | 193nm laser and inspection system |
US9608399B2 (en) | 2013-03-18 | 2017-03-28 | Kla-Tencor Corporation | 193 nm laser and an inspection system using a 193 nm laser |
GB2517187B (en) | 2013-08-14 | 2016-09-14 | Duvas Tech Ltd | Multipass spectroscopic absorption cell |
US9804101B2 (en) | 2014-03-20 | 2017-10-31 | Kla-Tencor Corporation | System and method for reducing the bandwidth of a laser and an inspection system and method using a laser |
WO2015174819A2 (en) * | 2014-05-16 | 2015-11-19 | Mimos Berhad | Method for producing narrow spectral linewidths |
US9419407B2 (en) | 2014-09-25 | 2016-08-16 | Kla-Tencor Corporation | Laser assembly and inspection system using monolithic bandwidth narrowing apparatus |
US9748729B2 (en) | 2014-10-03 | 2017-08-29 | Kla-Tencor Corporation | 183NM laser and inspection system |
JP6266813B2 (ja) * | 2015-10-16 | 2018-01-24 | Jx金属株式会社 | 光変調素子および電界センサ |
US10921553B2 (en) | 2015-11-13 | 2021-02-16 | Duvas Technologies Limited | Optical alignment apparatuses and methods for optics used in absorption cell spectrometers |
US10175555B2 (en) | 2017-01-03 | 2019-01-08 | KLA—Tencor Corporation | 183 nm CW laser and inspection system |
US20210351560A1 (en) * | 2018-09-27 | 2021-11-11 | Outsight | A LASER DEVICE FOR LASER DETECTION AND RANGING (LiDAR) |
KR102613795B1 (ko) | 2020-12-17 | 2023-12-14 | 재단법인 구미전자정보기술원 | 선폭이 조절된 광을 이용한 오브젝트 스캔 방법 및 장치 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11298083A (ja) * | 1998-04-15 | 1999-10-29 | Komatsu Ltd | 注入同期型狭帯域レーザ |
JP2002223018A (ja) * | 2001-01-26 | 2002-08-09 | Mitsubishi Heavy Ind Ltd | レーザ波長の制御システム、及び、レーザ波長の制御方法 |
JP2002299734A (ja) * | 2001-04-04 | 2002-10-11 | Mitsubishi Cable Ind Ltd | 光利得等化器、光増幅装置、および光通信システム |
JP2003195372A (ja) * | 2001-12-26 | 2003-07-09 | Komatsu Ltd | 紫外線レーザ装置 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3594384B2 (ja) | 1995-12-08 | 2004-11-24 | ソニー株式会社 | 半導体露光装置、投影露光装置及び回路パターン製造方法 |
US7468998B2 (en) * | 2005-03-25 | 2008-12-23 | Pavilion Integration Corporation | Radio frequency modulation of variable degree and automatic power control using external photodiode sensor for low-noise lasers of various wavelengths |
WO2007099847A1 (ja) * | 2006-03-03 | 2007-09-07 | Matsushita Electric Industrial Co., Ltd. | 照明光源及びレーザ投射装置 |
US7599413B2 (en) * | 2006-05-19 | 2009-10-06 | Pavilion Integration Corp. | Self-contained module for injecting signal into slave laser without any modifications or adaptations to it |
US20080261382A1 (en) * | 2007-04-19 | 2008-10-23 | Andrei Starodoumov | Wafer dicing using a fiber mopa |
JP4858499B2 (ja) | 2008-07-01 | 2012-01-18 | ソニー株式会社 | レーザ光源装置及びこれを用いたレーザ照射装置 |
US7993012B2 (en) * | 2008-09-30 | 2011-08-09 | Microvision, Inc. | Laser display system with optical feedback configured to reduce speckle artifacts |
-
2011
- 2011-05-23 WO PCT/JP2011/061754 patent/WO2011148895A1/ja active Application Filing
- 2011-05-23 JP JP2012517254A patent/JP5914329B2/ja active Active
-
2012
- 2012-11-08 US US13/671,657 patent/US8625645B2/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11298083A (ja) * | 1998-04-15 | 1999-10-29 | Komatsu Ltd | 注入同期型狭帯域レーザ |
JP2002223018A (ja) * | 2001-01-26 | 2002-08-09 | Mitsubishi Heavy Ind Ltd | レーザ波長の制御システム、及び、レーザ波長の制御方法 |
JP2002299734A (ja) * | 2001-04-04 | 2002-10-11 | Mitsubishi Cable Ind Ltd | 光利得等化器、光増幅装置、および光通信システム |
JP2003195372A (ja) * | 2001-12-26 | 2003-07-09 | Komatsu Ltd | 紫外線レーザ装置 |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9373935B2 (en) | 2014-02-05 | 2016-06-21 | Huawei Technologies Co., Ltd. | Optical lasing device and method for generating a lasing mode in such device |
JP2015149478A (ja) * | 2014-02-05 | 2015-08-20 | ▲ホア▼▲ウェイ▼技術有限公司 | 光学レーザー装置及び当該装置においてレーザー発振モードを生成する方法 |
WO2016142996A1 (ja) * | 2015-03-06 | 2016-09-15 | ギガフォトン株式会社 | 固体レーザシステム、及び露光装置用レーザ装置 |
CN107210576A (zh) * | 2015-03-06 | 2017-09-26 | 极光先进雷射株式会社 | 固体激光系统和曝光装置用激光装置 |
US20170338619A1 (en) * | 2015-03-06 | 2017-11-23 | Gigaphoton Inc. | Solid-state laser system and laser apparatus used for exposure apparatus |
JPWO2016142996A1 (ja) * | 2015-03-06 | 2017-12-28 | ギガフォトン株式会社 | 固体レーザシステム、及び露光装置用レーザ装置 |
US9929529B2 (en) | 2015-03-06 | 2018-03-27 | Gigaphoton Inc. | Solid-state laser system and laser apparatus used for exposure apparatus |
CN107210576B (zh) * | 2015-03-06 | 2019-08-16 | 极光先进雷射株式会社 | 固体激光系统和曝光装置用激光装置 |
JP2018010123A (ja) * | 2016-07-13 | 2018-01-18 | 株式会社ディスコ | 波長変換装置 |
JP2021114622A (ja) * | 2017-01-16 | 2021-08-05 | サイマー リミテッド ライアビリティ カンパニー | エキシマ光源におけるスペックルの低減 |
JP7104828B2 (ja) | 2017-01-16 | 2022-07-21 | サイマー リミテッド ライアビリティ カンパニー | エキシマ光源におけるスペックルの低減 |
KR20190087855A (ko) * | 2018-01-17 | 2019-07-25 | 국방과학연구소 | 광 출력 장치 및 그 방법. |
KR102012846B1 (ko) * | 2018-01-17 | 2019-08-21 | 국방과학연구소 | 광 출력 장치 및 그 방법. |
JPWO2020084685A1 (ja) * | 2018-10-23 | 2021-09-09 | ギガフォトン株式会社 | レーザシステム、及び電子デバイスの製造方法 |
JP7170055B2 (ja) | 2018-10-23 | 2022-11-11 | ギガフォトン株式会社 | レーザシステム、及び電子デバイスの製造方法 |
US11804697B2 (en) | 2018-10-23 | 2023-10-31 | Gigaphoton Inc. | Laser system and electronic device manufacturing method |
Also Published As
Publication number | Publication date |
---|---|
JPWO2011148895A1 (ja) | 2013-07-25 |
JP5914329B2 (ja) | 2016-05-11 |
US8625645B2 (en) | 2014-01-07 |
US20130064259A1 (en) | 2013-03-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5914329B2 (ja) | 固体レーザ装置およびレーザシステム | |
US20200292805A1 (en) | Optical measurement for illuminating a sample with filtered light and measuring fluorescence from the sample | |
US8804778B2 (en) | Laser apparatus and extreme ultraviolet light source apparatus | |
US10418775B2 (en) | External cavity tunable laser with dual beam outputs | |
EP2264841B1 (en) | Mode locking methods and apparatus | |
JP5558839B2 (ja) | 角度走査及び分散手順を用いて波長掃引レーザを利用するための方法、構成及び装置 | |
JP5637669B2 (ja) | パルス幅変換装置および光増幅システム | |
US7724789B2 (en) | Method and apparatus for optical mode multiplexing of multimode lasers and arrays | |
US7426223B2 (en) | Coherent light source and optical device | |
WO2015140901A1 (ja) | レーザシステム | |
JP2004193545A (ja) | スペクトル依存性空間フィルタリングによるレーザの同調方法およびレーザ | |
EP3079009B1 (en) | Multi-wavelength laser device | |
TWI790390B (zh) | 雷射光源及具有雷射光源之雷射投影器 | |
JP2006019603A (ja) | コヒーレント光源および光学装置 | |
JP2020534571A (ja) | 広帯域出力を有する調整可能光源 | |
JP5410344B2 (ja) | レーザ装置 | |
WO2013128780A1 (ja) | レーザ装置 | |
WO2003012544A1 (en) | Broad-band variable-wavelength laser beam generator | |
US20100272135A1 (en) | Self-Seeded Wavelength Conversion | |
WO2023112308A1 (ja) | レーザシステム、パルスレーザ光の生成方法、及び電子デバイスの製造方法 | |
JP3176682B2 (ja) | 波長可変レーザー装置 | |
JP5524381B2 (ja) | パルス幅変換装置および光増幅システム | |
Henriksson et al. | Tandem PPKTP and ZGP OPO for mid-infrared generation | |
JP2016500482A (ja) | エキシマーレーザーの複合キャビティー | |
WO2023218782A1 (ja) | 光源装置及び制御方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11786594 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012517254 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
32PN | Ep: public notification in the ep bulletin as address of the adressee cannot be established |
Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 01.03.2013) |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 11786594 Country of ref document: EP Kind code of ref document: A1 |