JP2001326407A - Co2 pulsed laser device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CO2 pulsed laser device in which isotope CO2 is not consumed and in which a laser at a wavelength not available so far is oscillated stably for a longtime. SOLUTION: A gas introduction part (3) by which an isotope mixed gas containing at least one of isotope CO and the isotope CO2 is introduced as a laser gas and a CO2 regeneration part (4) wherein CO which is generated when CO2 is decomposed by a laser oscillation is recombined with O2 are connected to a laser-gas flow channel (2) to a laser head (1). The inside of a system is formed to be of an airtight structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CO ₂ pulse laser device. For more information,
The invention of this application relates to a CO ₂ pulse laser device capable of stably oscillating a laser having an unprecedented wavelength for a long time without consuming the isotope CO ₂ .

[0002]

_2. Description of the Related Art CO ₂ pulse lasers
It is a tunable laser with the highest output in the infrared wavelength region of 11 μm, and is used for photochemical reactions including material processing and isotope enrichment. Particularly in isotope enrichment, B, C, S,
Besides being applied to Si and the like, it is also used as a driver of a Raman laser for U concentration.

However, a CO ₂ pulse laser is about 100
Although a specific oscillation line is provided, since the oscillation wavelength is uniquely determined by the rotational and vibrational levels of the CO ₂ molecule, the application range of the CO ₂ pulse laser is in fact extremely limited.

[0004] Natural CO ₂ is composed of approximately ¹² C and ¹⁶ O. Therefore, C and O of the CO ₂ molecule are converted to ¹³ C and ¹⁴ C, respectively.
By substituting with other isotopes such as C, ¹⁷ O and ¹⁸ O,
It is expected that the oscillation wavelength of the laser shifts due to the difference in the vibration level based on the mass difference, and the wavelength selectivity is expanded.

However, actually, CO ₂ →
Since a decomposition reaction of CO + 1/2 O ₂ occurs and CO ₂ is consumed, a large amount of CO ₂ gas is required for the laser gas.
Isotopic gases are scarce and very expensive, and thus, isotope CO ₂ pulsed lasers have not been realized.

[0006] The invention of this application has been made in view of the above circumstances, and the isotope CO ₂ is not consumed,
It is an object of the present invention to provide a CO ₂ pulse laser device capable of stably oscillating a laser having an unprecedented wavelength for a long time.

[0007]

Means for Solving the Problems The invention of this application is as described above.
To solve the problem of laser
In the gas flow path, isotope CO or isotope CO_TwoAt least
Laser isotope mixed gas containing either one
Gas introduction part to introduce and CO by laser oscillation _TwoIs disassembled
CO and O generated_TwoAre recombined and CO_TwoPlay to C
O_TwoThe regeneration unit is connected and the inside of the system is sealed.
CO characterized by the following_TwoPulse laser device (Claim 1)
provide.

In the invention of this application, the isotope CO and the isotope CO ₂ are such that at least one of C and O is an isotope mixture, and ¹² C and ¹⁴ C are selected as the isotope C, It is preferable that ¹⁶ O and ¹⁸ O are selected for the isotope O (Claim 2), and that the ratio of the amount of ¹⁶ O to ¹⁸ O in the isotope mixed gas is 1: 1 (Claim 3). Provided as an embodiment.

Hereinafter, the CO of the present invention will be described with reference to the drawings.
_{The two-} pulse laser device will be described in more detail.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the CO ₂ pulse laser device of the invention of the present application, the CO ₂ regenerating section is connected to the laser gas flow path to the laser head as described above, and the inside of the system has a closed structure. CO and O ₂ generated by decomposition of CO ₂ by laser oscillation are recombined and regenerated to CO ₂ , and the isotope CO
The mixed gas of ₂ can be returned to the laser head in a sealed state. This eliminates isotope CO ₂ consumption and mitigates the impact of the scarce and very expensive isotope gas. Further, a laser having an unprecedented wavelength can be stably oscillated for a long time, and continuous operation can be performed.

A specific configuration of the CO ₂ pulse laser device of the present invention can be shown, for example, in a block diagram of FIG.

As shown in FIG. 1, for example,
Invention CO_TwoIn a pulse laser device, a laser head
Isotope CO or isotope in laser gas flow path to (1) (2)
Body CO _TwoIsotope mixed gas containing at least one of
Gas introduction part (3) that introduces gas as laser gas is connected
Is done. The isotope mixed gas flows from the gas inlet (3)
Supplied to the laser head (1) through the gas flow path (2).
And used for laser oscillation.

Further, the CO ₂ regenerating section (4) as described above is connected to the laser gas flow path (2). As the CO ₂ regeneration section (4), for example, as shown in FIG. 1, a catalyst (4a) for recombining CO and O ₂ generated by decomposition of CO ₂ by laser oscillation can be used. Examples of the catalyst (4a) include platinum (Pt), palladium (Pd), nickel oxide (NiO), copper oxide (CuO), and the like. Of course, such a catalyst (4) is provided in the CO ₂ regeneration section (4).
It is also possible to adopt an appropriate one other than a). For example, CO is decomposed by plasma decomposition or photo decomposition, and CO is decomposed.
_For example, reproduction of ₂ is performed.

Further, in the CO ₂ pulse laser device of the invention of this application, as shown in FIG. 1, a pressure regulator (5), a diaphragm pump (6), a mass flow meter (7) are provided in a laser gas flow path (2). , A filter (8) and the like. Further, an exhaust path (9) can be connected to the laser gas flow path (2), and a valve (10) and a rotary pump (11) can be connected to the exhaust path (9). In this case as well, in the CO ₂ pulse laser device of the invention of this application, as described above, the inside of the system has a sealed structure, and the sealed state can be maintained.

When laser oscillation is performed in the CO ₂ pulse laser apparatus shown in FIG. 1, first, the valve (10) connected to the exhaust path (9) is opened, the rotary pump (11) is operated, and the system is operated. After evacuating the inside, a predetermined amount of the isotope mixed gas is introduced into the laser gas flow path (2) from the gas introduction section (3), and then the valve (11) is closed to close the system. Thereafter, the diaphragm pump (7) is operated, and laser is oscillated in the laser head (1) while circulating the isotope mixed gas as a laser gas in the system.

The isotope CO and the isotope CO ₂ in the isotope mixed gas introduced into the system from the gas introduction part (3) are C or O
Is an isotope mixture. For example, ¹² C and ¹⁴ C are selected for isotope C, and ¹⁶ O and ¹⁸ O are selected for isotope O. By supplying the isotope CO and the isotope mixed gas of the isotope CO ₂ to the laser head (1) in this manner, asymmetric vibration based on the mass difference occurs in ¹⁶ O—C— ¹⁸ O, and the natural isotope ratio is reduced. In CO ₂ , an oscillation of an odd number of rotational levels that cannot occur due to the symmetry of the CO ₂ molecule is obtained. In order to reliably obtain the oscillation of the odd rotational level, specifically, the P17 and P19 lines described later, it is necessary to set the quantity ratio of ¹⁶ O and ¹⁸ O in the isotope mixed gas to 1: 1. preferable.

[0017]

In CO ₂ pulsed laser apparatus of the invention of this application shown in EXAMPLES 1, 5% as a laser gas gas introduction section (3) to the laser gas passage _{^{(1) C 18 O 2 +}} 3% C 16
O ₂ + 4% C ¹⁶ O + 16% N ₂ + 72% He ( ¹⁶ O / ¹⁸ O
= 1) was introduced, also, CO ₂ performs reproduction of CO ₂ in the reproducing unit (4), to oscillate the laser at a repetition number 10Hz in the laser head (1) with an isotope gas mixture is circulated in the system, Infrared spectrometer (1) shown in FIG.
It was measured in 2). Table 1 shows the oscillation wavelength line in the 10P region after 27.8 hours when the energy of the laser beam is almost stabilized and the laser energy.

[0018]

[Table 1]

Oscillations of odd lines P17 and P19 were observed in addition to the even lines obtained with CO ₂ having a natural isotope ratio.

FIG. 2 is a graph showing the change over time in the output energy of the P17 and P19 lines.

As can be seen from FIG. 2, in the oscillation of these odd lines, the laser energy becomes almost constant after about 16 hours, and almost stable laser oscillation is obtained after about 28 hours (10 ⁶ shots). . It is confirmed that laser oscillation of an unprecedented wavelength can be stably obtained for a long time.

Of course, the invention of this application is not limited by the above embodiments and examples. It goes without saying that various aspects are possible for details such as the specific configuration of each part of the apparatus, the type of isotope, and the quantitative ratio.

[0023]

As described in detail above, according to the invention of this application, the isotope CO ₂ is not consumed, and a laser having an unprecedented wavelength can be stably oscillated for a long time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a CO ₂ pulse laser device according to the present invention.

FIG. 2 is a graph showing a time change of output energy of lines P17 and P19.

[Explanation of symbols]

1 Laser head 2 Laser gas flow path 3 Gas introduction section 4 CO ₂ regeneration section 4a Catalyst 5 Pressure regulator 6 Diaphragm pump 7 Mass flow meter 8 Filter 9 Exhaust path 10 Valve 11 Rotary pump 12 Infrared spectroscope

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Koichi Yagi, 1-2-1, Sengen, Tsukuba, Ibaraki Pref.

Claims (3)

[Claims] 1. A gas introduction unit for introducing, as a laser gas, an isotope mixed gas containing at least one of isotope CO and isotope CO ₂ into a laser gas flow path to a laser head, and CO ₂ is decomposed by laser oscillation. CO
And O ₂ was recombined, CO ₂ reproduction unit for reproducing the CO ₂ is connected, CO ₂ pulse laser apparatus, wherein a the system is a sealed structure. 2. A isotopes CO and isotopic CO ₂ Oite C or at least one of O is an isotope mixture, the isotope C is selected ¹² C and ¹⁴ C, isotopes O ¹⁶ O
And ¹⁸ O is CO ₂ pulse laser apparatus is selected according to claim 1, wherein. 3. The CO ₂ pulse laser device according to claim 2, wherein the quantity ratio of ¹⁶ O to ¹⁸ O in the isotope mixed gas is 1: 1.