RU2307433C1 - Liquid-coolant light filter for lasers - Google Patents

Abstract

FIELD: quantum electronics; solid-state lasers.

SUBSTANCE: proposed liquid-coolant light filter has 2,2'-dioxy-4,4-dimethoxybenzophenone dissolved in dimethyl-di-(isoamyloxy)silane doped with 1,8-naphthoilene-1',2'-benzimidazole, their concentration being 0.2 to 2 mmole/l.

EFFECT: enhanced service life of liquid-cooled laser due to filtering off detrimental part of pumping radiation.

1 cl, 2 dwg

Description

The invention relates to the field of quantum electronics and can be used in solid-state lasers, in particular in cooling systems of solid-state lasers.

The filtering heat-transfer filters used in quantum electronics should have a number of specific properties, such as absorption of the UV part of the radiation of a pump lamp (shorter than ~ 400 nm), a wide range of operating temperatures, low toxicity, low gas emission at a sufficiently high photochemical resistance to lamp radiation pumping [1]. The absorption of the harmful UV part of the pump radiation by such filter coolants leads to a substantial increase in the life of the laser system as a whole [2, 3].

It is known to use dimethyldi isoamyloxy silane as a coolant for lasers [4]. This composition has a wide range of operating temperatures, it is slightly toxic (hazard class IV according to GOST 12.1.007), it has a low gas emission, it has a high photochemical resistance. However, this composition of the coolant does not provide filtering of the UV part of the pump radiation, thereby limiting the life of the laser.

Also known is a liquid heat transfer filter for lasers based on a solution of 1,8-naphthoylene-1 ', 2'-benzimidazole in dimethyl di-isoamyloxy silane, in which the luminescent additive increases the laser efficiency and reduces its generation threshold [5, prototype]. However, this composition of the coolant does not provide a sufficiently complete filtering of the UV part of the pump radiation, which limits the life of the laser.

The aim of the present invention is to increase the life of the liquid-cooled laser due to the most complete filtering of the harmful part of the pump radiation. This goal is achieved by using a solution of 2,2'-dioxo-4,4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane with the addition of 1,8-naphthoylene-1 'as the composition of the heat-transfer fluid filter; , 2'-benzimidazole in a concentration of from 0.2 to 2 mmol / L.

As can be seen from figure 2 (curve 2), 1,8-naphthoylene-1 \ 2'-benzimidazole has a significantly greater absorption than 2,2'-dioxo-4,4'-dimethoxybenzimidazole in the region A, <300 nm, that when it is introduced into the composition of the coolant compensates for the too high transmission of the composition of the prototype in this part of the spectrum.

In order to determine the spectral characteristics of the claimed composition of the coolant-light filter, various coolants based on dimethyl-di- (isoamyloxy) silane were tested, in addition to the filtering aid of 2,2'-dioxo-4,4'-dimethoxybenzophenone (C ₁ = 1 mmol / L), 1,8-naphthoylene-1 ', 2'-benzimidazole was introduced at a concentration of C ₃ = 0.1-2 mmol / L. The thickness of the liquid layer is h = 2 mm, which corresponds to a typical value of the thickness of the gap between the pump lamp in the used laser quantrons [1].

The transmission spectra of the compositions of the inventive coolant-filter are shown in figure 1 at C ₂ = 0.1 (curve 2); 0.2 (curve 3); 2 (curve 4) mmol / L. As can be seen from figure 1, an increase in the concentration of 1,8-naphthoylene-1 ', 2'-benzimidazole to a value of C ₂ = 0.2 mmol / L or more leads to complete filtering of the dangerous part of the UV radiation. The upper limit of C ₃ = 2 mmol / L is determined by the ultimate solubility of 1,8-naphthoylene (1 ', 2') benzimidazole in a solution of 2,2'-dioxo-4,4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane .

Due to the luminescent properties of 1,8-naphthoylene-1 ', 2'-benzimidazole, the hazardous part of UV radiation absorbed in the coolant filter is reradiated to the region of the first main band of the neodymium medium (λ _max ≈530 nm), which, according to [5], can lead to to reduce the generation threshold and increase the efficiency of a neodymium laser with the claimed composition of the coolant-filter.

Examples. Four compositions of a liquid heat carrier-light filter were made, for which transmission spectra were measured in a layer 2 mm thick at different concentrations of C _{3 of the} luminescent additive of 1,8-naphthoylene-1 ', 2'-benzimidazole in a solution of 2,2'-dioxo-4 , 4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane.

Example 1. The composition of the liquid coolant filter for lasers, consisting of a solution of 2,2'-dioxo-4,4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane at d = 1 mmol / l (curve 1 in figure 1 )

Example 2. The composition of the liquid coolant filter for lasers, consisting of a solution of 2,2'-dioxo-4,4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane at C ₁ = 1 mmol / l, with the addition of this composition 1,8-naphthoylene-1 ′, 2′-benzimidazole at a concentration of C ₃ = 0.1 mmol / L (curve 2 in FIG. 1).

Example 3. The composition of the liquid coolant filter for lasers, consisting of a solution of 2,2'-dioxo-4,4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane at C ₁ = 1 mmol / l, with the addition of this composition 1,8-naphthoylene-1 ′, 2′-benzimidazole at a concentration of C ₃ = 0.2 mmol / L (curve 3 in FIG. 1).

Example 4. The composition of the liquid coolant filter for lasers, consisting of a solution of 2,2'-dioxo-4,4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane at C ₁ = 1 mmol / l, with the addition of this composition 1,8-naphthoylene-1 ′, 2′-benzimidazole at a concentration of d = 0.2 mmol / L (curve 3 in FIG. 1).

Example 4. The composition of the liquid coolant filter for lasers, consisting of a solution of 2,2'-dioxo-4,4'-dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane at C ₁ = 1 mmol / l, with the addition of this composition 1,8-naphthoylene-1 ′, 2′-benzimidazole at a concentration of C ₂ = 2 mmol / L (curve 4 in FIG. 1).

Thus, it can be seen from the above data that the use of the inventive composition of the liquid coolant-filter leads to the most complete filtering of harmful UV radiation from the pump lamps, the inventive composition satisfies the above requirements for coolants-filters for lasers.

Information sources

1. B.R.Belostotsky, Yu.V. Lyubavsky, V.M. Ovchinnikov. The basics of laser technology. Solid-state OKG // M .: Sov. Radio, 1972, 408 pp.

2. V.M. Volynkin, A.A. Mac, Yu.N. Mikhailov, A.N. Pogodaev, A.I. Stepanov. - Optical-mechanical industry. 1968, No. 3, p. 65-68.

3. V.M. Volynkin, A.N. Pogodaev. - Quantum Electronics, 1971, No. 3, pp. 115-116.

4. RF patent No. 2031499 of 05.15.81.

5. RF patent No. 2068606 from 10.27.96.

Claims (1)

The composition of the liquid coolant filter for lasers, characterized in that it contains 1,8-naphthoylene-1 ', 2'-benzimidazole in a concentration of from 0.2 to 2 mmol / l, a solution of 2,2'-dioxi-4,4' -dimethoxybenzophenone in dimethyl-di- (isoamyloxy) silane the rest.

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