JP2003332654A - Optical amplifier, light source device using the optical amplifier, optical therapeutic device using the light source device, and aligner using the light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently utilize excited light supplied into an optical amplification waveguide and efficiently amplify light. <P>SOLUTION: Excited light made incident form a first excited light waveguide 5a and a signal light made incident from a first signal light waveguide 5b are combined by a first wavelength division multiplexer 6 and they are led into an optical amplification waveguide 3. Then, they are separated by a second wavelength division multiplexer 8, and the excited light is allowed to exit to a second excited light waveguide 9a and the amplified signal light is allowed to exit to a second signal light waveguide 9b. In this case, the excited light outgoing to the second excited light waveguide 9a is reflected by an optical mirror 10, and enters the optical amplification waveguide 3 through the second excited light waveguide 9a and the second wavelength division multiplexer 8. Thus, the excited light can be used again by being reflected by the optical mirror 10, improving the efficiency of amplification of the signal light. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amplification device for amplifying irradiation light such as light from a laser light source, a light source device using this light amplification device, and a phototherapy device using this light source device. And an exposure apparatus.

[0002]

2. Description of the Related Art There are optical fiber amplifiers and optical waveguide amplifiers as means for amplifying infrared light or visible light of a single wavelength generated from a laser light source such as a semiconductor laser. this is,
By supplying excitation light to the amplification optical fiber and the amplification optical waveguide to which a rare earth element such as erbium (Er) is added, and exciting the added rare earth element, the population inversion of the energy level of the outer shell electron of the rare earth element is obtained. It is formed and amplifies the light incident on the optical fiber or the optical waveguide.

[0003]

When light is amplified by the optical fiber amplifier and the optical waveguide amplifier configured as described above, all of the pumping light supplied to these amplifiers is used for pumping the added rare earth element. Rather, some of them only pass through the optical fiber or optical waveguide as they are and do not contribute to optical amplification. Therefore, there is a problem that the pumping light cannot be used efficiently and the amplification efficiency of the light is not good.

The present invention has been made in view of these problems.
It is an object of the present invention to provide an optical fiber for amplification that constitutes an optical amplifier, and an optical amplifier that can efficiently perform optical amplification by efficiently using pumping light supplied into an optical amplification waveguide. To do.

Another object of the present invention is to provide a light source device constructed by using such a light amplification device, and further provide an exposure device and a phototherapy device constructed by using this light source device. The purpose is to do.

[0006]

In order to achieve such an object, an optical amplifying device according to the present invention comprises an optical amplifying waveguide formed on a glass substrate having a predetermined cross-sectional shape, and an optical amplifying waveguide. When the signal light and the pumping light enter the optical amplification waveguide from the inlet of the optical amplification waveguide, the multiplexing / demultiplexing means is provided in the optical amplification waveguide. The signal light and the pumping light that have been amplified through the inside are separated and emitted from the outlet. On top of that, an excitation light reflecting means for reflecting the excitation light separated and emitted by the multiplexing / demultiplexing means is provided, and the excitation light reflected by the excitation light reflecting means is exited via the multiplexing / demultiplexing means. The light is made incident on the inside of the optical amplification waveguide. In this way, the pumping light that has been incident from the entrance and used to amplify the signal light is
Since the light can be reused by being reflected by the reflecting means and again entering the optical amplification waveguide, the amplification efficiency of the signal light is improved.

The multiplexing / demultiplexing means can be composed of a wavelength division multiplexer, and the optical amplification waveguide has a size capable of maintaining a single mode. The excitation light reflecting means may be composed of an optical mirror or a reflective Bragg diffraction grating.

A second optical amplifying device according to the present invention is an optical amplifying waveguide formed on a glass substrate having a predetermined cross-sectional shape, and a first combining portion provided at the entrance of the optical amplifying waveguide. The optical multiplexer includes a wave unit and a second multiplexing / demultiplexing unit provided at the exit of the optical amplification waveguide, and the first multiplexing / demultiplexing unit causes the signal light incident from the outside to enter the optical amplification waveguide from the entrance. Then, the second multiplexing / demultiplexing means is configured to cause the pumping light, which is incident from the outside, to enter the optical amplification waveguide from the outlet. Further, the first multiplexing / demultiplexing means causes the pumping light that has entered the optical amplification waveguide from the outlet via the second multiplexing / demultiplexing means to exit through the path different from the signal light entrance path. And the second multiplexing / demultiplexing means separates the signal light, which is incident from the entrance portion into the optical amplification waveguide via the first multiplexing / demultiplexing means and is amplified, from the incident path of the excitation light. Is configured to be emitted to the outside from the outlet via the path. Further, an excitation light reflecting means for reflecting the excitation light separated and emitted by the first multiplexing / demultiplexing means is provided, and the excitation light reflected by the excitation light reflecting means is provided to the first multiplexing / demultiplexing means. The light is made incident on the inside of the optical amplification waveguide through the entrance. Also in this case, the pumping light is reused to improve the amplification efficiency.

In this optical amplifying device, the first multiplexing / demultiplexing means and the second multiplexing / demultiplexing means can each be composed of a wavelength division multiplexer, and the optical amplification waveguide has a size capable of maintaining a single mode. To be done. The excitation light reflecting means is composed of an optical mirror and a reflective Bragg diffraction grating.

A third optical amplifying apparatus according to the present invention comprises one amplifying optical fiber and a multiplexing / demultiplexing means provided at the exit of the amplifying optical fiber, and the signal light and the pumping light are the amplifying optical fibers. When input into the amplification optical fiber from the inlet of the optical fiber, the multiplexer / demultiplexer is configured to separate the signal light and the pump light amplified through the amplification optical fiber and to emit the separated signal light from the outlet. . On top of that, an excitation light reflecting means for reflecting the excitation light separated and emitted by the multiplexing / demultiplexing means is provided, and the excitation light reflected by the excitation light reflecting means is exited via the multiplexing / demultiplexing means. The light is incident on the optical fiber for amplification from the section.

Also in this optical amplifying apparatus, the multiplexing / demultiplexing means can be constituted by a wavelength division multiplexer, the amplifying optical fiber has a size capable of maintaining a single mode, and the excitation light reflecting means is an optical mirror or , A reflective Bragg grating.

A fourth optical amplifying device according to the present invention is provided with one amplification optical fiber, a first multiplexing / demultiplexing means provided at the entrance of the amplification optical fiber, and an exit of the amplification optical fiber. And a second multiplexing / demultiplexing means, wherein the first multiplexing / demultiplexing means causes the signal light incident from the outside to enter the amplification optical fiber from the entrance portion, and the second multiplexing / demultiplexing means causes the excitation to enter from the outside. It is configured to allow light to enter the optical amplification waveguide from the outlet. Further, the first multiplexing / demultiplexing means is
The pumping light that has entered the amplification optical fiber from the outlet via the second multiplexer / demultiplexer is output to the outside from the inlet via a route different from the incident route of the signal light, and the second multiplexer / demultiplexer is used. The means emits the signal light, which is incident and amplified in the amplification optical fiber from the entrance portion through the first multiplexing / demultiplexing means, to the outside from the exit portion through a path different from the entrance path of the excitation light. Is configured as follows. Further, a pumping light reflecting means for reflecting the pumping light separated and emitted by the first multiplexing / demultiplexing means is provided, and the pumping light reflected by the pumping light reflecting means is supplied to the first multiplexing / demultiplexing means. The light is made incident on the inside of the amplification optical fiber from the entrance via the.

Also in this optical amplifying apparatus, each of the first multiplexing / demultiplexing means and the second multiplexing / demultiplexing means is composed of a wavelength division multiplexer, and the amplification optical fiber has a size capable of maintaining a single mode. The excitation light reflecting means is composed of an optical mirror and a reflection type Bragg diffraction grating.

A light source device according to the present invention comprises any one of the first to fourth optical amplification devices according to the present invention described above, an irradiation light source for emitting irradiation light, and an excitation light source for emitting excitation light. The irradiation light from the irradiation light source and the excitation light from the excitation light source are introduced into the optical amplification waveguide from the inlet or the outlet, and the irradiation light is amplified and combined by the action of the excitation light in the optical amplification waveguide. It is configured to be separated by the wave means and emitted from the outlet. In the above light source device, the irradiation light source may be composed of a laser light source that emits laser light of a predetermined wavelength.

On the other hand, the phototherapy device according to the present invention comprises a light source device having the above-mentioned structure, a wavelength converter for converting the irradiation light emitted from the outlet of the light source device into therapeutic irradiation light of a predetermined wavelength, and a wavelength. An irradiation optical system that guides and irradiates the irradiation light converted by the converter to the treatment site.

An exposure apparatus according to the present invention further comprises a light source device having the above-mentioned structure, a wavelength converter for converting the irradiation light emitted from the outlet of the light source device into irradiation light of a predetermined wavelength, and a predetermined wavelength converter. A mask supporting unit that holds a photomask provided with an exposure pattern, an object holding unit that holds an exposure target, and irradiation light converted by a wavelength converter are applied to the photomask held by the mask supporting unit. The illumination optical system and the projection optical system for irradiating the exposure object held by the object holding unit with the irradiation light that has been irradiated onto the photomask through the illumination optical system and passed through the photomask.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

[0018]

[First Embodiment] An optical amplifying device 1-1 according to a first embodiment of the present invention is shown in FIG. 1, in which a central glass substrate 2 made of glass to which a rare earth element such as erbium (Er) is added.
The glass substrate is formed by bonding left and right glass substrates 4 and 7 made of normal glass (that is, glass to which a rare earth element such as erbium (Er) is not added) to the left and right in the middle. Inside the central glass substrate 2, an optical amplification waveguide 3 extending from a left bonding surface (bonding surface with the left glass substrate 4) 2a to a right bonding surface (bonding surface with the right glass substrate 7) 2b is provided. This optical amplification waveguide 3 is shown in FIG.
As shown in FIG. 2 showing the cross section along the arrow II-II of FIG. 2, the light refraction region having a circular cross section is formed inside the central glass substrate 2.

The left glass substrate 4 has a first excitation optical waveguide 5a and a first signal optical waveguide 5b extending from the left end surface 4a thereof.
Are provided, and these waveguides 5 a and 5 b are joined by the first wavelength division multiplexer 6 and connected to the optical amplification waveguide 3. On the right glass substrate 7, there are provided a second wavelength division multiplexer 8 connected to the optical amplification waveguide 3, and a second pumping optical waveguide 9a and a second signal optical waveguide 9b branched and extending from the second wavelength division multiplexer 8. The waveguides 9a and 9b are provided in the right end surface 7a of the right glass substrate 7. In addition, the second excitation optical waveguide 9 on the right end surface 7a of the right glass substrate 7
An optical mirror 10 for specularly reflecting light passing therethrough is provided at the portion where a is open.

When the signal light is amplified by using the optical amplifying device 1-1 having such a configuration, the first pumping optical waveguide 5a is used.
The excitation light is incident on the first signal optical waveguide 5b, and the signal light to be amplified is incident on the first signal optical waveguide 5b. The pumping light and the signal light are combined by the first wavelength division multiplexer 6 and guided into the optical amplification waveguide 3. Thereby, in the optical amplification waveguide 3, by exciting the added rare earth element with the excitation light, an inversion distribution is formed in the energy level of the outer shell electron of the rare earth element, and the signal light is amplified. The signal light and the pumping light thus amplified are separated from the optical amplification waveguide 3 into the signal light and the pumping light by the second wavelength division multiplexer 8, and the pumping light is emitted to the second pumping optical waveguide 9a and amplified. The signal light thus generated is emitted to the second signal optical waveguide 9b.

Here, the exit of the second excitation optical waveguide 9a faces the optical mirror 10 arranged on the right end face 7a of the right substrate 7, and the excitation light emitted to the second excitation optical waveguide 9a is The light is reflected by the optical mirror 10 and again emitted from the second pumping optical waveguide 9a to the optical amplification waveguide 3 through the second wavelength division multiplexer 8. Therefore, in the optical amplification waveguide 3, a rare earth element is generated by the excitation light reflected from the mirror 10 and returned from the second excitation optical waveguide 9a in addition to the excitation light transmitted from the first excitation optical waveguide 5a. The element is excited,
Highly efficient amplification is performed.

[0022]

[Wavelength Division Multiplexer] The first and second wavelength division multiplexers 6 and 8 will be described with reference to FIG. Here, a configuration example of the wavelength division multiplexer is shown using reference numeral 20, and as shown in the figure, two single-mode waveguides gradually approach each other, and then merge into one and branch again into two. have. That is, as shown in FIG. 3A, the first and second inlet-side waveguides 21 and 22 gradually approach each other and the coupling portion 25
The first and second exit-side waveguides 2 after coupling at
3 and 24, and the coupling portion (region) 25 has a structure in which two modes, an even mode and an odd mode, exist (see FIG. 3B). Since the propagation constants of these two modes are different, both modes propagate while interfering with the coupling portion 25, and the optical power periodically meanders.

Therefore, when the length of the coupling portion 25 is set so that the phase difference between the even and odd modes is an odd multiple of π, light is emitted to the waveguide on the side opposite to the incident waveguide. For example, the light that has entered the first inlet-side waveguide 21 is emitted to the second outlet-side waveguide 24. On the contrary, when the length of the coupling portion 25 is set so that the phase difference between the even and odd modes is an even multiple of π, light is emitted to the waveguide on the same side as the incident waveguide.
For example, the light incident on the first inlet side waveguide 21 is emitted to the first outlet side waveguide 23.

Since the propagation constant differs depending on the wavelength, the phase difference between the even and odd modes at the signal light wavelength is an even multiple of π, and the even and odd modes at the pump light wavelength. When the length of the coupling section 25 is set so that the phase difference is an odd multiple of π, the signal light is emitted to the waveguide on the same side,
The excitation light is emitted to the waveguide on the opposite side. Therefore, for example, when pumping light enters the first inlet-side waveguide 21 and signal light enters the second inlet-side waveguide 22, both pumping light and signal light are emitted to the second outlet-side waveguide 24. , Both are combined. Note that, for example, when both the excitation light and the signal light are incident on the first inlet side waveguide 21, the signal light is emitted to the first outlet side waveguide 23, and the excitation light is emitted to the second outlet side waveguide 24. And both are demultiplexed.

[0025]

[Manufacturing Method] An example of a method of manufacturing the optical amplifying device 1-1 will be briefly described. This manufacturing method is called an ion exchange method, and its manufacturing process is shown in order in FIGS. In this method, first, as shown in FIG. 4, a glass substrate to which a rare earth element such as Er (erbium) is added (phosphate glass, BK7 glass, soda lime glass, etc.)
A metal film 16 is formed by patterning on the surface of 15 by forming an opening 17 in accordance with the waveguide shape by using a photolithography technique used in a semiconductor manufacturing process. Opening 16
Corresponds to the above-mentioned shape of the optical amplification waveguide 3, as is apparent from the shape of FIG.

Next, as shown in FIG. 5, the metal film 16 was patterned and formed on the melt 20 in which a neutral salt containing monovalent ions such as Ag was heated to a temperature higher than the melting point to be melted. The glass substrate 15 is dipped for a predetermined time. As a result, as shown in FIG. 6, in the portion of the opening 17 exposed to the molten liquid 20, the high-refractive region 18 (hatching is performed) where Na ions are replaced with monovalent metal ions near the glass surface to form a waveguide. Area) is formed. Next, after removing the metal film 16 as shown in FIG. 7, an electric field is applied with the upper and lower surfaces sandwiched by the electrodes 21a and 21b as shown in FIG. When embedded in the substrate 15, the optical amplification device 1-1 shown in FIG. 1 is manufactured. At this time, the optical waveguide 3 is sized to be in a single mode by appropriately setting the ion concentration, temperature, immersion time (ion exchange time), applied electric field, etc. of the melt 20.

Although the case where the optical amplification waveguide 3 is formed in the central glass substrate 2 has been described above,
The same applies to the case where various waveguides and wavelength division multiplexers are provided in the left and right glass substrates 4 and 7. The method for manufacturing the optical amplifying device 1-1 is not limited to the above-described method, but the ion-implantation method is used only in the portion where the optical waveguide is formed to selectively add the rare earth element such as Er. Alternatively, it may be produced by using a flame deposition method and a reactive ion etching method (IEICE Transactions CI, vol. J77-CI, No. 5, p.
p. 214-221, 1994).

[0028]

Second Embodiment Next, a second embodiment according to the present invention will be described with reference to FIG. The optical amplifying device 1-2 according to this embodiment is only partially different in configuration from the optical amplifying device 1-1 according to the first embodiment shown in FIG. The same components are given the same numbers and their explanations are omitted. The optical amplifying device 1-2 differs from the optical amplifying device 1-1 shown in FIG. 1 only in that a Bragg diffraction grating 11 is provided on the second pumping optical waveguide 9a in place of the optical mirror 10. The other configurations are exactly the same. The Bragg diffraction grating 11 has a function of reflecting the pumping light separated into the second pumping optical waveguide 9 a by the second wavelength division multiplexer 8, and performs the same operation as the optical mirror 10. Therefore, also in the optical amplifying device 1-2, in the optical amplifying waveguide 3, in addition to the pumping light sent from the first pumping optical waveguide 5a, the Bragg diffraction grating 11 reflects the second pumping light. The rare earth element is also excited by the excitation light returning from the optical waveguide 9a, and highly efficient amplification is performed.

[0029]

[Third Embodiment] A third embodiment of the present invention will be described with reference to FIG. The optical amplification device 1-3 according to this embodiment and the optical amplification device 1-4 according to a fourth embodiment described later have the same configuration as the optical amplification device 1-1 according to the first embodiment shown in FIG. The same numbers are assigned to the parts and the description thereof is omitted. This optical amplifier 1-
3, the optical mirror 10 arranged on the right end face of the right glass substrate 7 in the optical amplifying device 1-1 is removed, and instead, the optical mirror 10 is placed on the left end face of the left glass substrate 4 at a position facing the first excitation optical waveguide 5a. The point that the mirror 10 is provided is different from the optical amplifying device 1-1 of FIG.

In this optical amplifying device 1-3, the signal light is input from the first signal optical waveguide 5b and the pump light is input from the second pump optical waveguide 9a. The signal light thus entered is transmitted through the first wavelength division multiplexer 6 to the optical amplification waveguide 3
Since the input excitation light is guided into the optical amplification waveguide 3 via the second wavelength division multiplexer 8, the signal light is amplified in the optical amplification waveguide 3 and then amplified as described above. The generated signal light is sent to the second signal optical waveguide 9 by the second wavelength division multiplexer 8.
It is emitted to the outside through b. On the other hand, the pumping light passes through the optical amplification waveguide 3 and then is emitted to the first pumping optical waveguide 5a by the first wavelength division multiplexer 6 and is reflected by the optical mirror 10, and again passes through the first pumping optical waveguide 5a to reach the first pumping optical waveguide 5a. It is guided to the optical amplification waveguide 3 via the one wavelength division multiplexer 6. For this reason,
According to this optical amplifier 1-3, in the optical amplification waveguide 3, in addition to the pumping light sent from the second pumping optical waveguide 9a, the first pumping optical waveguide 5a is reflected by the optical mirror 10. The rare earth element is also excited by the excitation light returning from the device, and highly efficient amplification is performed.

[0031]

Fourth Embodiment A fourth embodiment according to the present invention will be described with reference to FIG. In the optical amplifying device 1-4 according to this embodiment, the Bragg diffraction grating 1 is provided on the first pumping optical waveguide 5a on the left end face of the left glass substrate 4.
1 is different from the optical amplifier 1-3 according to the third embodiment. Also in this optical amplifier 1-4, the signal light is incident from the first signal optical waveguide 5b and is excited by the second pumping optical waveguide 9a. Therefore, the first
The signal light guided into the optical amplification waveguide 3 via the wavelength division multiplexer 6 is amplified by the amplification effect of the pumping light guided into the optical amplification waveguide 3 via the second wavelength division multiplexer 8. ,
The light is emitted from the second wavelength division multiplexer 8 to the outside through the second signal optical waveguide 9b. On the other hand, the excitation light passes through the optical amplification waveguide 3 and then is emitted to the first excitation optical waveguide 5a by the first wavelength division multiplexer 6 and reflected by the Bragg diffraction grating 11,
It is guided again to the optical amplification waveguide 3 through the first pumping optical waveguide 5a and the first wavelength division multiplexer 6. Therefore, also in the optical amplifying device 1-4, in the optical amplifying waveguide 3, in addition to the pumping light sent from the second pumping optical waveguide 9a, the first pumping light is reflected by the Bragg diffraction grating 11. The rare earth element is also excited by the excitation light returning from the optical waveguide 5a, and highly efficient amplification is performed.

[0032]

[Light Source Device] Next, a light source device 30 configured by using the optical amplifying device having the above-described configuration will be described with reference to FIG. The light source device 30 includes a laser light generator 31 that generates a laser light and an optical amplifier 40 that amplifies the laser light generated from the laser light generator 31.

The laser light generator 31 has a laser 32 that oscillates at a desired wavelength. The laser 32 is composed of, for example, an oscillation wavelength of 1.544 μm, InGaAsP, and a DFB semiconductor laser pulse-driven. As the oscillation wavelength control means of the laser light, for example, when a DFB semiconductor laser is used as the laser, it can be achieved by controlling the temperature of the DFB semiconductor laser. By this method, the oscillation wavelength is further stabilized and kept constant. The wavelength can be controlled to, or the output wavelength can be finely adjusted.

The oscillation wavelength of the DFB semiconductor laser is used as the monitor wavelength for the feedback control when controlling the oscillation wavelength to a predetermined wavelength. The semiconductor laser 32 is provided with a pulse control means 33 that causes pulse oscillation by controlling the current. As a result, the pulse width of the pulsed light produced is 0.5 ns to 3 ns
Can be controlled in the range of, and the repetition frequency is 100
Range below kHz (for example, 10 kHz to 100 kHz)
Control range). In this configuration example, as an example,
The pulse control means 33 produces pulsed light having a pulse width of 1 ns and a repetition frequency of 100 kHz.

The pulsed laser light output thus obtained is guided to the optical amplification section 40 through the optical isolator 34 and is amplified in the optical amplification section 40. This optical amplifier 4
At 0, amplification is first performed by the first-stage optical amplifier 41. The first-stage optical amplifier 41 is composed of the above-described optical amplifiers 1-1 to 4 and includes a semiconductor laser 41 for pumping.
The output (excitation light) from a is a wavelength division multiplexer (Wavele).
ngth Division Multiplexer (referred to as WDM) 41b, and performs optical amplification of laser light input through the optical isolator 34.

The output (laser light) of the first-stage optical amplifier 41 amplified in this way is guided to the optical splitter 43 through the narrow band filter 42a and the optical isolator 42b, and the optical splitter 43 divides it into a plurality of channels. It is divided in parallel. The second-stage optical amplifier 45 is connected to each of the plurality of divided channels. However, in FIG. 13, only one channel is shown as a representative.

The narrow band filter 42a cuts the ASE light generated by the optical amplifier 41 and transmits the output wavelength (wavelength width of about 1 pm or less) of the DFB semiconductor laser 32, so that the wavelength width of the transmitted light is reduced. Is substantially narrowed. This makes it possible to prevent the ASE light from entering the optical amplifier in the subsequent stage and lowering the amplification gain of the laser light. Here, it is preferable that the transmission wavelength width of the narrow band filter is about 1 pm, but since the wavelength width of the ASE light is about several tens nm, a narrow band filter having a transmission wavelength width of about 100 pm obtained at the present time should be used. Even if it is used, the ASE light can be cut to the extent that there is no practical problem.

The second stage optical amplifier 45 is also the optical amplifier 1 described above.
-1 to 4 and a semiconductor laser 45a for excitation
Output (pumping light) from WDM45b is input, and the output light amplified by the first stage optical amplifier 41 is further amplified. The output of the second-stage optical amplifier 45 passes through the narrow band filter 46a and the optical isolator 46b, and the output end 4
It is output from 7. The output terminal 47 is collected and bundled for all of the plurality of channels, and is output collectively.

In each of the above embodiments, in order to avoid the influence of returning light, an isolator or the like is appropriately inserted in each connection portion, and a narrow band filter is inserted in order to obtain a good EDFA amplification characteristic. Indicated. However, the location where the isolator or the narrow band filter is arranged, or the number thereof is not limited to the above-described embodiment, and may be appropriately determined depending on, for example, the required accuracy of the light source device according to the present invention. In some cases, at least one of the bandpass filters may not be provided.

The narrow band filter only needs to have a high transmittance with respect to only a desired wavelength, and the transmission wavelength width of the filter is 1 pm or less. By using the narrow band filter in this way, noise due to spontaneous emission ASE (Amplified Spontaneous Emission) generated in the optical amplifier can be reduced, and the AS from the optical amplifier in the previous stage can be reduced.
It is possible to suppress the decrease in the amplification factor of the fundamental wave output due to E.

[0041]

[Phototherapy device] The light source device 3 of the present invention having the above-mentioned configuration
A phototherapy device configured using 0 will be described below with reference to FIGS. 14 to 16. This phototherapy device 50
Irradiates the cornea with laser light to ablate the surface (PRK: Photorefractive Keratectomy) or ablate the inside of the incised cornea (LASIK: Laser
Intrastromal Keratomileusis) is a device that corrects the curvature or irregularity of the cornea to treat myopia, astigmatism, etc.

As shown in FIG. 14, the phototherapy device 50 basically includes a light source device 30 described above in a device casing 51.
And a wavelength conversion device 6 for converting the laser light amplified and output by the light source device 30 into a laser light of a desired wavelength.
0, an irradiation optical device 70 that guides and irradiates the laser light wavelength-converted by the wavelength conversion device 60 onto the surface (treatment region) of the cornea HC of the eyeball EY, and an observation optical device 80 that observes the treatment region. Consists of The base portion 52 of the device housing 51 is disposed on the XY moving table 53, and the XY moving table 53 causes the entire device housing 51 to move in the direction of arrow X in FIG. It can be moved in the Y direction, which is perpendicular to the paper surface.

The light source device 30 is configured as described above, and the laser light output from the output end 47 of the light source device 30 has a desired wavelength (wavelength 193 nm suitable for corneal treatment in this device, It is converted into a therapeutic laser beam having the same wavelength as the ArF excimer laser beam. The configuration of the wavelength conversion device 60 is shown in FIG. 15, in which a fundamental wave having a predetermined wavelength (wavelength of 1.544 μm in this embodiment) emitted from the output end 47 of the light source device 30 is generated by using a nonlinear optical crystal. Wavelength conversion to 8th harmonic (harmonic), Ar
An example of a configuration for generating 193 nm ultraviolet light having the same wavelength as the F excimer laser is shown. The fundamental wave having a wavelength of 1.544 μm (frequency ω) output from the output end 47 is transmitted through the nonlinear optical crystals 61, 62, 63 from left to right in the figure and is output. The nonlinear optical crystals 61, 6
Between the two and 63, as shown in the figure, the condenser lenses 64, 65
Is provided.

When these fundamental waves pass through the non-linear optical crystal 61, the generation of the second harmonic causes double the frequency ω of the fundamental wave,
That is, 2 of frequency 2ω (wavelength is 1/2, 772 nm)
Double harmonics are generated. The generated double wave advances to the right and enters the next nonlinear optical crystal 62. Here, the second harmonic is generated again, and the frequency 2ω of the incident wave is doubled, that is, the frequency 4ω which is four times the fundamental wave (the wavelength is ¼ of 386n).
m) is generated. The generated fourth harmonic wave further advances to the right nonlinear optical crystal 63, where the second harmonic generation is performed again, and the frequency of the incident wave is 4ω, that is, 8 times the fundamental wave. Harmonics (wavelength is 1
/ 8/8 193 nm).

As the non-linear optical crystal used for the wavelength conversion, for example, a LiB ₃ O ₅ (LBO) crystal is used as the non-linear optical crystal 61 for converting the fundamental wave into the second harmonic wave. LiB ₃ O is used for the nonlinear optical crystal 62 for conversion into
_A Sr ₂ Be ₂ B ₂ O ₇ (SBBO) crystal is used as the nonlinear optical crystal 63 for converting the ₅ (LBO) crystal from the 4th harmonic to the 8th harmonic. Here, from the fundamental wave using the LBO crystal, 2
LBO is used for phase matching for wavelength conversion when converting to harmonics.
Non-Critical Phase Match
ing: Use NCPM. Since NCPM does not cause an angle deviation (Walk-off) between the fundamental wave and the second harmonic wave in the nonlinear optical crystal, it enables highly efficient conversion into the second harmonic wave, and the generated second harmonic wave is the Walk. This is advantageous because the beam is not deformed by -off.

In this way, the laser light having the wavelength of 193 nm (the laser light having the same wavelength as that of the ArF excimer laser light) converted and output by the wavelength conversion device 60 is guided to the surface of the cornea HC of the eyeball EY. The irradiation optical device 70 and the observation optical device 80 that irradiate the light will be described. In the light source device 30, the solid-state laser is composed of a DFB semiconductor laser or a fiber laser having an oscillation wavelength in the range of 1.51 μm to 1.59 μm. The wavelength of the laser light is 189 nm to 199
It is converted into a laser beam having an 8th harmonic within the range of nm and output. As described above, this laser light is a laser light having substantially the same wavelength as the ArF excimer laser light, but the repetition frequency of its pulse oscillation is as high as 100 kHz.

The structures of the irradiation optical device 70 and the observation optical device 80 are shown in FIG. Irradiation optical device 70
Is a condensing lens 71 for condensing a laser beam having a wavelength of 193 nm obtained by converting the wavelength of the light from the light source device 30 by the wavelength conversion device 60 into a thin beam shape, and the beam shape thus condensed. And a dichroic mirror 72 for reflecting the laser light to irradiate the surface of the cornea HC of the eyeball EY to be treated. As a result, the surface of the cornea HC is irradiated with laser light as spot light, and evaporation of this portion is performed. At this time, by the XY moving table 53, the entire apparatus housing 51 is moved in the X direction and the Y direction to scan and move the laser light spot irradiated on the surface of the cornea HC, and the corneal surface is ablated. Treat myopia, astigmatism, hyperopia, etc.

Such treatment is performed by an operator such as an ophthalmologist controlling the operation of the XY moving table 53 while visually observing through the observation optical device 80. The observation optical device 80 includes an illumination lamp 85 that illuminates the surface of the cornea HC of the eyeball EY to be treated, and an objective lens that receives light from the cornea HC illuminated by the illumination lamp 85 through the dichroic mirror 72. 81, a prism 82 that reflects the light from the objective lens 81, and an eyepiece lens 83 that receives the light. The magnified image of the cornea HC can be observed through the eyepiece lens 83.

[0049]

[Exposure Apparatus] Next, an exposure apparatus 100 configured by using the above-described light source device 30 and used in a photolithography process which is one of semiconductor manufacturing processes will be described with reference to FIG. The exposure equipment used in the photolithography process is the same as in photolithography in principle, and the device pattern precisely drawn on the photomask (reticle) can be used for semiconductor wafers and glass substrates coated with photoresist. Optically projected and transferred on top. The exposure apparatus 100 includes a light source device 30 and the wavelength conversion device 1 described above.
01, an illumination optical system 102, a mask support base 103 for supporting a photomask (reticle) 110, a projection optical system 104, a mounting base 105 for mounting and holding a semiconductor wafer 115, and a mounting base 105 for horizontal movement. Drive device 10
And 6.

In the exposure apparatus 100, the laser light output from the output end 47 of the light source device 30 as described above is input to the wavelength conversion device 101, where the laser light of the wavelength required for the exposure of the semiconductor wafer 115 is emitted. The wavelength is converted into laser light. The wavelength-converted laser light is input to the illumination optical system 102 composed of a plurality of lenses, passes through the irradiation optical system 102, and is applied to the entire surface of the photomask 110 supported by the mask support 103. The light thus irradiated and passing through the photomask 110 has an image of the device pattern drawn on the photomask 100,
This light is applied to a predetermined position of the semiconductor wafer 115 mounted on the mounting table 105 via the projection optical system 104. At this time, the image of the device pattern of the photomask 110 is reduced on the semiconductor wafer 115 by the projection optical system 104 and imagewise exposed.

[0051]

Other Embodiments The above-described optical amplifiers 1-1 to 4 are waveguide-type optical amplifiers in which a high-refractive region in which a rare earth element such as erbium is added is formed in a glass substrate. Although it is a device, the present invention is similarly applicable to an optical fiber amplifying device configured by an optical fiber in which a rare earth element such as erbium is added instead of such an optical amplifying waveguide. This case is the same as the above except that an optical fiber type optical amplifying device is configured by using an optical fiber instead of each waveguide in the optical amplifying devices 1-1 to 4.

[0052]

As described above, according to the optical amplifying device of the present invention, when the signal light and the pumping light enter the optical amplification waveguide from the entrance of the optical amplification waveguide, they are combined and demultiplexed. Means for separating the signal light amplified by passing through the optical amplification waveguide and the pumping light and outputting the separated pumping light from the outlet, and the pumping light for separating the pumping light separated and emitted by the multiplexing / demultiplexing means A light reflecting means is provided, and the pumping light reflected by the pumping light reflecting means is made to enter the optical amplification waveguide from the outlet through the multiplexer / demultiplexer, so that it is incident from the inlet. The pumping light that has been used for amplifying the signal light can be reused by being reflected by the reflecting means and incident again into the optical amplification waveguide, and the amplification efficiency of the signal light is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an optical amplifying device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the optical amplifying device taken along line II-II in FIG.

FIG. 3 is an explanatory diagram showing a configuration of a wavelength division multiplexer used in the optical amplification device.

FIG. 4 is an explanatory view showing a manufacturing process of the optical amplifying device of the present invention by an ion exchange method.

FIG. 5 is an explanatory view showing a manufacturing process of the optical amplifying device of the present invention by an ion exchange method.

FIG. 6 is an explanatory view showing a manufacturing process of the optical amplifying device of the present invention by an ion exchange method.

FIG. 7 is an explanatory view showing a manufacturing process of the optical amplifying device of the present invention by an ion exchange method.

FIG. 8 is an explanatory view showing a manufacturing process of the optical amplifying device of the present invention by an ion exchange method.

FIG. 9 is an explanatory view showing a manufacturing process of the optical amplifying device of the present invention by an ion exchange method.

FIG. 10 is a cross-sectional view showing an optical amplifier device according to a second embodiment of the present invention.

FIG. 11 is a sectional view showing an optical amplifier device according to a third embodiment of the present invention.

FIG. 12 is a cross-sectional view showing an optical amplifier device according to a fourth embodiment of the present invention.

FIG. 13 is a schematic diagram showing a configuration of a light source device according to the present invention.

FIG. 14 is a schematic diagram showing a configuration of a phototherapy device according to the present invention.

FIG. 15 is a schematic diagram showing a configuration of a wavelength conversion device that constitutes the phototherapy device.

FIG. 16 is a schematic view showing the configurations of an irradiation optical device and an observation optical device that form the above-mentioned phototherapy device.

FIG. 17 is a schematic view showing the arrangement of an exposure apparatus according to the present invention.

[Explanation of symbols]

1-1, 1-2, 1-3, 1-4 Optical amplification device 2,4,7 glass substrate 3 Optical amplification waveguide 5a, 9a First and second excitation optical waveguides 5b, 9b First and second signal optical waveguides 6,8 Wavelength division multiplexer 30 light source device 31 Laser light generator 40 optical amplifier 50 Phototherapy device 60 wavelength converter 70 Irradiation optical device 80 Observation optical device 100 exposure equipment 101 Wavelength converter 102 Illumination optical system 103 Mask support 104 Projection optical system 110 photomask (reticle) 115 Semiconductor wafer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/027 H01L 21/30 515B F term (reference) 4C026 AA02 BB03 BB06 BB08 FF03 FF34 4C082 RA08 RC02 RC06 RC09 RE03 RE21 5F046 CA04 CA08 CB04 CB17 CB22 CB25 5F072 AB09 AK06 AK10 JJ02 YY09 YY11

Claims (27)

[Claims] 1. An optical amplification waveguide formed on a glass substrate so as to have a predetermined cross-sectional shape, and a multiplexing / demultiplexing means provided at an exit of the optical amplification waveguide. Is incident on the inside of the optical amplification waveguide from the entrance of the optical amplification waveguide, the multiplexing / demultiplexing means passes through the inside of the optical amplification waveguide to amplify the signal light and the excitation light. It is configured to be separated and emitted from the outlet portion, and is provided with excitation light reflecting means for reflecting the excitation light separated and emitted by the multiplexing / demultiplexing means, and is reflected by the excitation light reflecting means. An optical amplifying device, wherein the pumping light is made to enter the optical amplification waveguide from the outlet through the multiplexing / demultiplexing means. 2. The optical amplifying device according to claim 1, wherein the multiplexer / demultiplexer comprises a wavelength division multiplexer. 3. The optical amplification device according to claim 1, wherein the optical amplification waveguide has a size capable of maintaining a single mode. 4. The optical amplifying device according to claim 1, wherein the excitation light reflecting means comprises an optical mirror. 5. The optical amplifying device according to claim 1, wherein the pumping light reflecting means comprises a reflection type Bragg diffraction grating. 6. An optical amplification waveguide formed on a glass substrate so as to have a predetermined cross-sectional shape, a first multiplexing / demultiplexing means provided at an entrance of the optical amplification waveguide, and the optical amplification waveguide. Second optical multiplexer / demultiplexer provided at the outlet of the second optical multiplexer, wherein the first optical multiplexer / demultiplexer causes the signal light incident from the outside to enter the optical amplification waveguide from the inlet, The multiplexing / demultiplexing unit causes the pumping light incident from the outside to enter the optical amplification waveguide from the outlet, and the first multiplexing / demultiplexing unit outputs the excitation light from the outlet via the second multiplexing / demultiplexing unit. The pumping light that has entered the optical amplification waveguide is emitted to the outside from the entrance portion via a path different from the entrance path of the signal light, and the second multiplexing / demultiplexing means includes the first The signal light that has been incident on the optical amplification waveguide from the entrance through the multiplexer / demultiplexer and is amplified is Excitation light reflection means for emitting the excitation light to the outside from the exit portion via a path different from the incident path of the electromotive light and reflecting the excitation light separated and emitted by the first multiplexing / demultiplexing means is provided. The excitation light reflected by the excitation light reflection means
An optical amplifying device, characterized in that it is made to enter the inside of the optical amplification waveguide from the entrance through a multiplexing / demultiplexing means. 7. The optical amplifying device according to claim 6, wherein each of the first multiplexing / demultiplexing means and the second multiplexing / demultiplexing means comprises a wavelength division multiplexer. 8. The optical amplification device according to claim 6, wherein the optical amplification waveguide has a size capable of maintaining a single mode. 9. The optical amplifying device according to claim 6, wherein the excitation light reflecting means comprises an optical mirror. 10. The optical amplifying device according to claim 6, wherein the pumping light reflecting means comprises a reflection type Bragg diffraction grating. 11. An amplification optical fiber, comprising: one amplification optical fiber; and multiplexing / demultiplexing means provided at the exit of the amplification optical fiber, wherein signal light and pump light are introduced from the entrance of the amplification optical fiber to the amplification optical fiber. When the light is incident on the inside, the multiplexing / demultiplexing means is configured to separate the signal light amplified by passing through the amplification optical fiber and the pumping light, and to emit the separated signal light from the outlet. Excitation light reflecting means for reflecting the excitation light separated and emitted by the demultiplexing means is provided, and the excitation light reflected by the excitation light reflecting means is output via the combining / demultiplexing means. An optical amplifying device, characterized in that it is made to enter into the amplification optical fiber from a section. 12. The optical amplifying device according to claim 11, wherein the multiplexer / demultiplexer comprises a wavelength division multiplexer. 13. The optical amplification device according to claim 11, wherein the amplification optical fiber has a size capable of maintaining a single mode. 14. The optical amplifying device according to claim 11, wherein the excitation light reflecting means is an optical mirror. 15. The optical amplifying device according to claim 11, wherein the pumping light reflecting means comprises a reflective Bragg diffraction grating. 16. A single amplification optical fiber, a first multiplexing / demultiplexing unit provided at the inlet of the amplification optical fiber, and a second optical multiplexer provided at the outlet of the amplification optical fiber.
A multiplexer / demultiplexer, wherein the first multiplexer / demultiplexer causes the signal light incident from the outside to enter the amplification optical fiber from the entrance, and the second multiplexer / demultiplexer enters from the outside. The pumping light is made incident into the optical amplification waveguide from the outlet portion, and the first multiplexing / demultiplexing means is made incident on the amplification optical fiber from the outlet portion via the second multiplexing / demultiplexing means. Excitation light is emitted to the outside from the inlet through a path different from the incident path of the signal light, and the second multiplexing / demultiplexing means is output from the inlet through the first multiplexing / demultiplexing means. The signal light that has been incident and amplified in the amplification optical fiber is emitted to the outside from the outlet through a path different from the incident path of the excitation light, and separated by the first multiplexing / demultiplexing means. Is provided with excitation light reflecting means for reflecting the excitation light emitted as The pumping light reflected by the pumping light reflecting means is made to enter the amplification optical fiber from the inlet through the first multiplexing / demultiplexing means. Optical amplifier. 17. The optical amplifying device according to claim 16, wherein the first multiplexing / demultiplexing means and the second multiplexing / demultiplexing means each comprise a wavelength division multiplexer. 18. The optical amplification device according to claim 16, wherein the amplification optical fiber has a size capable of maintaining a single mode. 19. The optical amplification device according to claim 16, wherein the excitation light reflection means is an optical mirror. 20. The optical amplifying device according to claim 16, wherein the pumping light reflecting means comprises a reflection type Bragg diffraction grating. 21. The light amplification device according to claim 1, an irradiation light source that emits irradiation light, and an excitation light source that emits excitation light, and the irradiation light from the irradiation light source and the A pumping light from a pumping light source is introduced into the optical amplification waveguide from the entrance, and the irradiation light is amplified by the action of the excitation light in the optical amplification waveguide and separated by the multiplexing / demultiplexing means. A light source device configured to emit light from the outlet portion. 22. The optical amplification device according to claim 6, an irradiation light source that emits irradiation light, and an excitation light source that emits excitation light, the irradiation light from the irradiation light source The pumping light from the pumping light source is introduced into the optical amplification waveguide from the inlet through the first multiplexer / demultiplexer, and the optical amplification guide is output from the outlet through the second multiplexer / demultiplexer. It is configured such that it is introduced into a waveguide, the irradiation light is amplified by the action of the excitation light in the optical amplification waveguide, and is separated by the second multiplexing / demultiplexing means and emitted from the outlet portion. Characteristic light source device. 23. The light amplification device according to claim 11, an irradiation light source for emitting irradiation light, and an excitation light source for emitting excitation light, the irradiation light from the irradiation light source and the excitation light source. The pumping light from a pumping light source is introduced into the amplification optical fiber from the inlet, and the irradiation light is amplified by the action of the pumping light in the amplification optical fiber and separated by the multiplexing / demultiplexing means, and the exit is obtained. A light source device configured to be emitted from a section. 24. The light amplification device according to claim 16, an irradiation light source that emits irradiation light, and an excitation light source that emits excitation light, the irradiation light from the irradiation light source The pumping light from the pumping light source is introduced into the amplification optical fiber from the inlet through the first multiplexer / demultiplexer, and the exit light is introduced into the amplification optical fiber through the second multiplexer / demultiplexer. And amplifying the irradiation light by the action of the excitation light in the amplification optical fiber, and
A light source device characterized in that it is separated by a multiplexing / demultiplexing means and emitted from the outlet. 25. The irradiation light source is a laser light source that emits laser light of a predetermined wavelength.
The light source device according to any one of 1 to 24. 26. The light source device according to claim 21, a wavelength converter that converts irradiation light emitted from the outlet of the light source device into therapeutic irradiation light having a predetermined wavelength, An optical treatment system comprising: an irradiation optical system that guides the irradiation light converted by the wavelength converter to a treatment site for irradiation. 27. A light source device according to claim 21, a wavelength converter for converting the irradiation light emitted from the outlet of the light source device into irradiation light of a predetermined wavelength, and a predetermined wavelength converter. A mask supporting unit that holds a photomask provided with an exposure pattern, an object holding unit that holds an exposure target, and irradiation light converted by the wavelength converter to a photomask held by the mask supporting unit. An illumination optical system for irradiating, and a projection optical system for irradiating the exposure object held by the object holding unit with the irradiation light which is irradiated on the photomask through the illumination optical system and has passed through the photomask. An exposure apparatus characterized by being configured.