JPH01312877A - Laser equipment - Google Patents

Abstract

PURPOSE:To support a Fabry-Perot etalon(FP) without producing a distortion and prevent contamination due to degasification and the like by supporting only one side glass of the FP with U-shaped rings made of fluororesin. CONSTITUTION:An FP 7 for tuning wavelengths is disposed between a laser oscillator and a partial reflecting mirror. A closed vessel 8 where the FP 7 is housed is filled with a gas and is sealed with anti-reflection(AR) coating glass 9. Only one of glass materials out of two sheets of them which form the FP 7 is supported in the closed vessel 8 by means of U-shaped rings 27 made of a fluororesin. In other words, if two sheets of glass are supported simultaneously, surplus force equal to slippage acts upon and gaps between two sheets of glass produce distortions. As only one side mirror is supported in order to prevent the distortions, no distortion of FP 7 appears very much and no degasification occurs even though a laser beam makes irregular reflection and strikes upon the U-shaped rings 27. Such a supporting system thus prevents contamination of the FP 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laser device, and more specifically, to a laser device incorporating a Fabry-Perot etalon for changing the wavelength of a laser oscillator. .

[Conventional technology]

Figure 4 shows, for example, the magazine ``IEE Journal of Phantom Electronics (IFiK).
K Jour-nal of Quantum Kle
ctronics) J QE-14 ('78)
This is a schematic configuration diagram of the conventional wavelength-stabilized laser device shown on pages 17 to 22. In the figure, a laser oscillator (1) with a structure for changing the wavelength internally, a Fabry-Perot etalon (2), and an optical The detector (5), the navigation mechanism (4) for changing the wavelength, and the laser oscillator (1).
The wavelength of the laser beam emitted from ) changes depending on the state of the optical resonator. In this example, the wavelength can be selected by changing the vanguard spacing. However, it is difficult to stabilize the selected wavelength with high precision due to thermal deformation and vibration of the co-imager, so the laser beam obtained from the laser oscillator (1) is The etalon (hereinafter referred to as F'P< 3
) The example shown in this figure is an attempt to stabilize the wavelength by measuring the wavelength. IFF (2) consists of two mirrors with high flatness facing each other with a gap d, and the center wavelength λ of the light that passes through the mirror surface at an angle θ.
m is a specific wavelength expressed as 2nd cosθ λm=□...(11).n is the refractive index between the gaps, and m is an integer.If 7F (2) with high resolution is used, the laser Of the oscillation wavelength distribution, the intensity of λm can be found.Since a laser beam generally has a certain divergence angle, only the beam component that satisfies equation (1) is FP (
2), forming coaxial fringes (ring-shaped interference fringes) centered on the optical axis of the beam. Therefore, FP(2
) is placed after the photodetector (3), when the wavelength changes, the position of the fringe changes and crosses over the photodetector (5).

Figure 5 shows the change in the intensity of the beam appearing on the photodetector (6) when the above fringe crosses the photodetector (6). The vertical axis is the output, and the horizontal axis is the distance from the center of the fringe. indicates the distance X. The winter peaks correspond to the difference in the order m of FP (2).The interval between the winter mountains is called a free spectral region, and the wavelength can be uniquely determined within this range.

Also, since Fuyuyama has a light intensity distribution that corresponds to the wavelength distribution of the laser beam, we process this to find the angle θ,
Further 1: Calculate the current wavelength λ, change the resonance interval with the servo mechanism (4) according to the result, and start the laser oscillator (1).
).

[Problem to be solved by the invention]

Conventional laser equipment is configured as described above, so
Depending on the method of fixing the FP, the external stress may be too strong, distorting the FP gap, and depending on the material used to hold the FP, scattered laser light may hit the holding member and generate gas, staining the FP and making it unstable. There was a problem in that it was not possible to obtain a laser wavelength with a certain wavelength.

This invention was made to solve the above-mentioned problems, and an object thereof is to obtain a laser device that can oscillate at a stable wavelength.

[Means to solve the problem]

In the first laser device according to the present invention, the glass element on only one side of the FP is held by a holding member made of fluororesin.

In the second laser device according to the present invention, the periphery of the glossy F'P is held by a packing made of fluororesin and a hardening silicone resin.

[For production]

In the first and second inventions, pp is maintained without distorting the FP gap.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 3. In Figure 3, a total reflection mirror (5) and a partial reflection mirror (6) are placed facing each other across a laser oscillator (1).A Fabry-Perot etalon (hereinafter abbreviated as FF) for wavelength tuning is shown. ) (7) is placed between the laser oscillator (1) and the partial reflection@! (6).The airtight container (8) containing the FP (7) is filled with gas, and the AR The frame (10) is attached to the oscillator (1) and holds the closed container (8).The volume expanding and contracting means (11) consisting of a bellows holds the closed container (8). (8), and this volume expansion/contraction means (11) is driven by a drive mechanism (12).The laser oscillator (1), the total reflection mirror (5), the partial reflection mirror (6) and the FP ( 7) Laser light (13)
is oscillated. A part of the laser beam (13) is taken out by a beam extraction mirror (14), and an interference filter (15) that transmits only one part of the laser beam (13) and a light intensity adjustment filter (16) that transmits only one part of the laser beam (1 part) are used. 7 for monitoring the structure with a gap via the diffusing integrator (17)
7 (f8). FP (18) is a sealed container (19
), and the sealed container (19) is sealed with AR coated glass (20).

Below FF (+87 is the lens (old), F'P (181
An image sensor (22
) are placed. This image sensor (22) is, for example, a -dimensional image sensor. or more optical elements (16
) to (22) are light shielding boxes (
230 - is housed, and an interference filter (15) is arranged so that the laser beam from the beam extraction mirror (14) can be incident thereon. The part surrounded by the broken line (24) is the wavelength monitor mechanism part. A temperature control means (25) is connected to the FP (18) to keep its temperature constant.

The image processing means (26) for analyzing the fringe includes a drive mechanism (
12).

As shown in Fig. 1, the sealed container (8) (or (19)) is made of a ■ ring (made of fluororesin) in which only the two glass sheets forming the FP (7) are made of fluororesin. 27th =
Therefore, it is held in a sealed container (87).

Subenas (28) made of fluororesin are interposed on both sides of the FP and the sealed container (8). Also, FP
(7) is pressed toward -10,000 by a spring (29), and the flange (30) holds the spring (29). The glass (9) is held down by a window flange (31), and O-rings (32) are inserted into the close contact portions of each member. The gas pipe (33) is connected to the volume expansion/contraction means (11
Connected twice a month.

In the above configuration, the FP (7) is made of two partially reflecting mirrors that are optically contacted by sandwiching the gear's width, but since the two mirrors are not necessarily concentric and are slightly misaligned, the mirror If two mirrors are supported at the same time, an extra force will be generated due to the misalignment and the gap will become distorted.To prevent this, only one mirror is supported. In addition, by supporting the mirror with a ring (2υ) made of fluororesin, the force is smaller than supporting it with an 0-ring, etc., so there is almost no distortion of the FP (7), and the laser light is diffusely reflected, causing the U ring to (27), there is no degassing, so the FP (7) will not be contaminated.

By using tetrafluoroethylene as the material for the U-ring (2υ), it is even more effective in preventing outgassing.

Figure 2 shows a sealed container (8) [or (19J) of another embodiment.
) part is shown, U ring (27) made of fluororesin and FP
(7) FP (
7) The curable silicone resin (34) for retention is inserted into the injection port (
35) is injected and filled. A laser reflective coating (36) is applied to the outer peripheral surface of the FP (7).

In addition, the same reference numerals as in FIG. 1 indicate the same parts.

The assembly procedure for the above configuration is as follows: First, the U9 link (2η
Set it on the FP (7) and use the fluororesin spanner (28).
Insert it into the airtight container (8). spring(
29) and attach the lid with the flange (30) set. After that, apply liquid silicone resin (54) before hardening to the injection port (
35) Inject and harden.

With this configuration, even if the laser beam (13) flies in the direction of the silicone resin (34) due to diffuse reflection, the outer periphery of the FP (7) is coated with a laser reflective coating (36).
The laser light is entrained by a laser reflective coating (36);
Since it does not hit the silicone resin, deterioration of the silicone resin (34) and gas generation are prevented. Furthermore, distortion of FP(η does not occur).

〔Effect of the invention〕

As described above, according to the first aspect of the present invention, only the glass on one side of the Fabry-Perot etalon is held by a U-ring made of fluororesin, so the Fabry-Perot etalon can be held without distortion, and there is no possibility of contamination due to degassing, etc. do not have.

Further, according to the second aspect of the present invention, since the Fabry-Perot etalon is held by the U-ring made of fluororesin and the silicone resin, the Fabry-Perot etalon can be held without distortion, and the Fabry-Perot etalon can be protected against gas emission. There is no.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention;
The figure is a sectional view of the main part of the second embodiment of the present invention, and FIG. 6 is the first factor or '! Fig. J2 is an optical circuit diagram of a laser device to which the one applied, Fig. 4 is an optical circuit diagram of a conventional laser device,
FIG. 5 is a fringe intensity distribution diagram of the one shown in FIG. (71, (18) ...Fabry-Perot etalon, (
8). (19)... Sealed container, (27)... H ring (support member, packing), (34)... Silicone resin. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A laser beam extracted from a wavelength-tunable laser oscillator is monitored by a wavelength monitoring mechanism, and the wavelength of the laser oscillator is adjusted by a Fabry-Perot etalon housed in a sealed container in accordance with the output signal of the wavelength monitoring mechanism. What is claimed is: 1. A laser device for changing the temperature, characterized by comprising a support member made of fluororesin inserted between the outer peripheral surface of the glass element on one side of the Fabry-Perot etalon and the sealed container. (2) A laser beam extracted from a wavelength-tunable laser oscillator is monitored by a wavelength monitoring mechanism, and the wavelength of the laser oscillator is adjusted by a Fabry-Perot etalon housed in a sealed container in accordance with the output signal of the wavelength monitoring mechanism. What is claimed is: 1. A laser device for changing the temperature, characterized in that a curable silicone resin is held between the outer peripheral surface of the Fabry-Perot etalon and the sealed container by a packing made of fluororesin.