Laser device and laser extraction method

Abstract

This laser device is provided with: a light extraction unit that extracts, from incident light, light in a wavelength band that contributes to laser oscillation; and a laser resonance unit that is provided with a medium into which the light of the wavelength band extracted by the light extraction unit is incident.

Description

Laser device and laser extraction method

[0001] The present invention relates to the field of laser technology.

[0002] Solar-pumped laser technology is known, in which sunlight is directly irradiated onto a laser medium to obtain a laser without using electric power (Non-Patent Document 1).

[0003] To ensure efficient oscillation, laser media that use sunlight as excitation light are doped with specific elements as sensitizers that absorb light of specific wavelengths and increase the energy required for laser oscillation.

[0004] Cai, Zitao, et al. "Efficient 38.8 W / m 2 solar pumped laser with a Ce: Nd: YAG crystal and a Fresnel lens." Optics Express 31.2 (2023): 1340-1353. https: / / opg.optica.org / oe / fulltext.cfm?uri=oe-31-2-1340

[0005] As mentioned above, specific elements are added to laser media that use sunlight as excitation light. Depending on the elements added to the laser media, the wavelengths that the laser media can absorb vary.

[0006] Sunlight contains light in a wide wavelength range, including wavelengths that do not contribute to laser oscillation. When light with wavelengths that do not contribute to oscillation is introduced into a laser medium, it generates heat and causes the laser medium to deteriorate, resulting in a decrease in oscillation efficiency. In other words, conventional technology has the problem of being unable to efficiently extract laser light from laser media that use sunlight as excitation light. Note that this problem is not limited to sunlight, but can occur with any light with a wide wavelength range when used as excitation light.

[0007] The present invention has been made in view of the above points, and aims to provide a technology for efficiently extracting laser light from a laser medium that uses light with a wide wavelength band, such as sunlight, as excitation light.

[0008] According to the disclosed technology, there is provided a laser device comprising: a light extraction section that extracts light of a wavelength band that contributes to laser oscillation from incident light; and a laser resonator that includes a medium into which the light of the wavelength band extracted by the light extraction section is incident.

[0009] The disclosed technology provides a technology for efficiently extracting laser light from a laser medium that uses light having a wide wavelength band, such as sunlight, as excitation light.

[0010] It is a diagram showing an example of the configuration of the laser device.It is a diagram showing a detailed configuration of the laser device.It is a flowchart for explaining the operation of the laser device.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0012] Below, we will explain a laser device that uses sunlight as excitation light to output a laser (e.g., a solid-state laser). In the following explanation, the laser medium may be referred to as a "medium." Note that in the following explanation, using sunlight as excitation light is one example. The configuration and operation described below can also be applied to cases where light other than sunlight (e.g., light from a lamp with a wide wavelength band) is used as excitation light.

[0013] (Device Configuration Example) An example of the configuration of a laser device according to this embodiment is shown in Fig. 1. As shown in Fig. 1, this laser device includes a light extraction unit 100 and a laser resonator unit 200. The functions of each unit are as follows:

[0014] Sunlight is incident on the light extraction unit 100. The light extraction unit 100 splits the incident sunlight and extracts light in a specific wavelength band that contributes to laser oscillation in the medium. The light in the specific wavelength band is incident on the laser resonator 200.

[0015] The laser resonator 200 includes a medium. The light in the specific wavelength band extracted by the light extraction unit 100 is light in a wavelength band suitable for the medium for laser oscillation. In other words, the light extraction unit 100 prevents light that does not contribute to laser oscillation from entering the medium.

[0016] The laser resonator 200 makes the light of the specific wavelength band extracted by the light extractor 100 incident on a medium as excitation light, and extracts an oscillated laser from the medium. The laser resonator 200 outputs the laser.

[0017] The light extraction unit 100 may output light in a plurality of wavelength bands. The laser resonator 200 may also include a plurality of media. Light in a wavelength band that contributes to laser oscillation is incident on each of the plurality of media, causing laser oscillation in each medium, and a laser is output from each medium.

[0018] The medium used in the laser cavity portion 200 may be any of a solid, liquid, and gas, as long as it is a medium that can cause laser oscillation by light.

[0019] (Detailed Configuration Example) A detailed configuration example of the laser device according to this embodiment is shown in Fig. 2. In this example, two media are used.

[0020] As shown in Fig. 2, the light extraction unit 100 has a spectroscope 110 and a condenser 120. For example, a prism, a diffraction grating, an optical filter, or the like can be used as the spectroscope 110. For example, an optical element such as a lens or an optical fiber can be used as the condenser 120. Alternatively, a reflecting mirror may be used as the condenser 120.

[0021] The laser cavity 200 has a half mirror 210, a medium A (220A), a medium B (220B), an external resonator mirror 230A, and an external resonator mirror 230B. In the example shown in FIG. 2 , the medium A is provided between the half mirror 210 and the external resonator mirror 230A, and the medium B is provided between the half mirror 210 and the external resonator mirror 230B. Note that a separate half mirror may be provided for each medium. In that case, the example shown in FIG. 2 includes two half mirrors. The half mirrors do not need to be in contact with the medium.

[0022] 2, the light separated by the light extraction unit 100 is incident on the end face of each medium via the half mirror 220. Resonance occurs between the half mirror 220 and the external resonator mirrors 230A / B, and a laser is output from the external resonator mirrors 230A / B.

[0023] Instead of the method of making light incident on the end face of each medium as described above, the light dispersed by the light extraction unit 100 may be made incident on the side face of each medium.

[0024] (Example of Operation) An example of operation of the laser device shown in Fig. 2 will be described in accordance with the procedure of the flowchart in Fig. 3. Here, medium A is assumed to be a medium that oscillates when light of wavelength band a and light of wavelength band b are introduced therein, and medium B is assumed to be a medium that oscillates when light of wavelength band a and light of wavelength band c are introduced therein.

[0025] In S101 (step 101), sunlight is incident on the spectroscope 110. In S102, the spectroscope 110 splits the sunlight into light of wavelength band a, light of wavelength band b, and light of wavelength band c. The split light is incident on the light collecting unit 120. The split light output from the light collecting unit 120 is incident on the laser resonator 200.

[0026] 2, the spectroscope 110 and the light collecting unit 120 are arranged so that the light in wavelength band a and the light in wavelength band b are incident on the end face of medium A, and the light in wavelength band a and the light in wavelength band c are incident on the end face of medium B. Therefore, the light in wavelength band a and the light in wavelength band b are incident on the end face of medium A, and the light in wavelength band a and the light in wavelength band c are incident on the end face of medium B.

[0027] As described above, the spectroscope 110 and the light collecting unit 120 may be arranged so that the light in wavelength band a and the light in wavelength band b are incident on the side surface of the medium A, and the light in wavelength band a and the light in wavelength band c are incident on the side surface of the medium B. In S103, lasers are output from each of the medium A and the medium B.

[0028] (Effects of the Technology Relating to the Embodiments) As described above, the laser device according to the present embodiment is configured to separate incident light into light of one or more wavelength bands, and introduce the light of each wavelength band into a medium specialized for the light of that wavelength band.

[0029] A laser device configured in this way can introduce into the medium only light in the wavelength band that contributes to laser oscillation, thereby increasing the laser light extraction efficiency and reducing the effects of heat and medium degradation compared to methods that do not involve spectroscopic analysis.

[0030] The following additional notes are provided regarding the above-described embodiments.

[0031] <Additional Notes> (Additional Item 1) A laser device comprising: a light extraction section that extracts light of a wavelength band that contributes to laser oscillation from incident light; and a laser resonator that includes a medium onto which the light of the wavelength band extracted by the light extraction section is incident. (Additional Item 2) The laser device according to Additional Item 1, wherein the light of the wavelength band is incident on an end face or a side face of the medium. (Additional Item 3) The laser device according to Additional Item 1, wherein the light extraction section includes a spectrometer that splits the incident light into light of a plurality of wavelength bands that each contributes to laser oscillation. (Additional Item 4) The laser device according to Additional Item 3, wherein the laser resonator includes a plurality of media, each of which is suitable for laser oscillation for at least one of the plurality of wavelength bands. (Additional Item 5) A laser extraction method performed by a laser device, comprising: a light extraction step of extracting light of a wavelength band that contributes to laser oscillation from incident light; and a laser extraction step of injecting the light of the wavelength band extracted by the light extraction step into a medium and extracting a laser from the medium.

[0032] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0033] REFERENCE SIGNS LIST 100 Light extraction section 110 Spectrometer 120 Light collection section 200 Laser resonator section 210 Half mirror 220A Medium A 220B Medium B 230A, 230B External resonator mirror 1000 Drive device 1001 Recording medium 1002 Auxiliary storage device 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input device 1008 Output device

Claims

1. A laser device comprising: a light extraction section that extracts light in a wavelength band that contributes to laser oscillation from incident light; and a laser resonator that has a medium into which the light in the wavelength band extracted by the light extraction section is incident.

2. The laser device according to claim 1, wherein light in the wavelength band is incident on an end face or a side face of the medium.

3. The laser device according to claim 1, wherein the light extraction unit includes a spectroscope that separates the incident light into light of multiple wavelength bands that each contribute to laser oscillation.

4. The laser device according to claim 3, wherein the laser resonator comprises a plurality of media, each of which is suitable for laser oscillation in at least one of the plurality of wavelength bands.

5. A laser extraction method performed by a laser device, comprising: a light extraction step of extracting light of a wavelength band that contributes to laser oscillation from incident light; and a laser extraction step of injecting the light of the wavelength band extracted by the light extraction step into a medium and extracting a laser from the medium.

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