JP6972626B2 - Calcogenide glass - Google Patents

Description

The present invention relates to chalcogenide glass.

As a light emitting body such as a laser medium or an optical amplifier medium, glass containing a transition metal ion that emits light when excited is used. In recent years, an infrared laser having a wavelength of 2 μm or more has been used as a laser for medical use, and glass as a laser medium needs to transmit infrared light. Therefore, as a laser medium, a material in which transition metal ions are dispersed in chalcogenide glass having excellent infrared transmission characteristics has been proposed. (See, for example, Patent Document 1)

Japanese Patent Publication No. 2004-510665

However, the chalcogenide glass described in Patent Document 1 has a problem that it contains arsenic, which is extremely toxic.

In view of the above, it is an object of the present invention to provide a chalcogenide glass having a low toxicity and a light emitting function having excellent infrared transmission characteristics.

The chalcogenide glass of the present invention is in mol%, Ge 0 to less than 20%, Sb 0 to 40%, Bi 0 to 20%, S + Se + Te 50 to 80%, and transition metal element 0.01 to 10%. It is characterized by containing.

The chalcogenide glass of the present invention contains Ge 2 to 20%, Sb 5 to 35%, Bi 1 to 20%, S + Se + Te 55 to 75%, and transition metal element 0.01 to 5% in mol%. Is preferable.

The chalcogenide glass of the present invention further preferably contains Sn 0 to 20% in mol%.

In the chalcogenide glass of the present invention, it is preferable that the transition metal element is at least one selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and rare earth elements.

In the chalcogenide glass of the present invention, the rare earth element may be at least one selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. preferable.

The chalcogenide glass of the present invention preferably contains substantially no As, Cd, Tl and Pb.

The illuminant of the present invention is characterized by being made of the above-mentioned chalcogenide glass.

The light emitter of the present invention is preferably in the form of a fiber.

The laser medium is characterized by comprising the above-mentioned light emitter.

According to the present invention, it is possible to provide a chalcogenide glass having a low toxicity and a light emitting function having excellent infrared transmission characteristics.

The chalcogenide glass of the present invention is in mol%, Ge 0 to less than 20%, Sb 0 to 40%, Bi 0 to 20%, S + Se + Te 50 to 80%, and transition metal element 0.01 to 10%. It is characterized by containing. The reasons for limiting the glass composition as described above are shown below. In the following description of the content of each component, "%" means "mol%" unless otherwise specified.

Ge is an essential component for forming a glass skeleton. The content of Ge is more than 0 to less than 20%, preferably less than 2 to 20%, more preferably 2 to 18%, still more preferably 4 to 15%. When Ge is not contained, it becomes difficult to vitrify. On the other hand, if the content of Ge is too large, Ge-based crystals tend to precipitate and the raw material cost tends to increase.

Sb is also an essential component for forming a glass skeleton. The content of Sb is more than 0 to less than 40%, preferably 5 to 35%, and more preferably 10 to 33%. If Sb is not contained, or if the content is too large, it becomes difficult to vitrify.

Bi is a component that promotes vitrification. In chalcogenide glass, S, Se, and Te, which are chalcogen elements, tend to volatilize when melted. Therefore, it becomes difficult to vitrify due to the compositional deviation and the inhomogeneity due to the low reactivity between Ge and Sb and the chalcogen element. Therefore, in the present invention, Bi is contained in the glass composition in order to promote vitrification. The reason why vitrification can be promoted by including Bi in the glass composition is as follows. Ge and Sb have melting points of 940 ° C and 630 ° C, respectively, while Bi has a low melting point of 270 ° C and melts at a relatively low temperature. Therefore, by adding Bi as a raw material, the chalcogen element reacts with Bi before it volatilizes, and vitrification is promoted. Bi also has the effect of improving the thermal stability of glass. However, if the Bi content is too high, it becomes difficult to vitrify. In view of the above, the Bi content is more than 0 to 20%, preferably 0.5 to 20%, more preferably 1 to 10%, and even more preferably 2 to 8%. ..

The chalcogen elements S, Se and Te are components that form a glass skeleton. The content of S + Se + Te (total amount of S, Se and Te) is 50 to 80%, preferably 55 to 75%, and more preferably 58 to 68%. If the content of S + Se + Te is too small, it becomes difficult to vitrify, while if it is too large, the weather resistance may decrease.

As the chalcogen element, S is preferably selected from the viewpoint of the wide vitrification range and the environment, and the content of S is preferably 30 to 80%.

The transition metal element is a component that imparts a light emitting function by being present as an ion in glass. The total amount of these contents is 0.01 to 10%, preferably 0.01 to 5%, more preferably 0.01 to 3%, and 0.01 to 1%. Is even more preferable. If the content of the transition metal element is too small, it becomes difficult to obtain sufficient intensity of light emission. On the other hand, if the amount is too large, concentration quenching may occur and the luminous efficiency may decrease. From the viewpoint of luminous efficiency, the transition metal element is preferably at least one selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu and rare earth elements. The rare earth element is preferably at least one selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

In addition to the above components, the chalcogenide glass of the present invention may contain the following components.

Sn is a component that widens the vitrification range and enhances the thermal stability of glass. The Sn content is preferably 0 to 20%, more preferably 0.5 to 10%. If the Sn content is too high, it becomes difficult to vitrify.

Zn, In, Ga and P are components that widen the vitrification range, and their contents are preferably 0 to 20%, respectively. If the content of these components is too high, it becomes difficult to vitrify.

Cl, F and I are components that widen the transmission wavelength range of infrared rays, and their contents are preferably 0 to 20%, respectively. If the content of these components is too high, the weather resistance tends to decrease.

It is preferable that the chalcogenide glass of the present invention does not substantially contain toxic substances As, Cd, Tl and Pb. In this way, the impact on the environment can be minimized. Here, "substantially not contained" means that it is intentionally not contained in the raw material, and does not exclude contamination at the impurity level. Objectively, it means that the content of each component is less than 1000 ppm.

The chalcogenide glass of the present invention has excellent infrared transmittance at a wavelength of about 1 to 12 μm. As an index for evaluating the infrared transmittance at a wavelength of about 1 to 12 μm, 50% transmission wavelength in the infrared region can be mentioned. The 50% transmission wavelength (thickness 2 mm) in the infrared region of the present invention is preferably 10 μm or more, and more preferably 11 μm or more.

The chalcogenide glass of the present invention can be produced, for example, as follows. First, the raw materials are prepared so as to have a desired composition. Put the raw material in a quartz glass ampoule that has been evacuated while heating, and seal it with an oxygen burner while evacuating. The sealed quartz glass ampoule is held at about 650 to 800 ° C. for 6 to 12 hours and then rapidly cooled to room temperature to obtain the chalcogenide glass of the present invention. As the raw material, elemental raw materials (Ge, Sb, Bi, S, Fe, Cr, Se, Te, etc.) may be used, and compound raw materials (GeS ₂ , Sb ₂ S ₃ , Bi ₂ S ₃ , FeS, etc.) may be used. Fe ₂ S ₃ , Cr ₂ S ₃ , CoS, Pr ₂ S _{3 and the} like) may be used.

Since the chalcogenide glass of the present invention contains a transition metal element which is a component that imparts a light emitting function, it functions as a light emitting body. Further, the illuminant made of chalcogenide glass is also excellent in infrared transmission characteristics, and is therefore suitable as a laser medium in the infrared region. The shape of the light emitting body is not particularly limited, but when used for a fiber laser or the like, it is preferably fiber-shaped.

The fibrous chalcogenide glass can be produced by processing the chalcogenide glass obtained above into a rod-shaped preform and then drawing a wire while heating under an inert atmosphere.

Further, the laser medium may be a fiber having a two-layer structure having a core made of fibrous chalcogenide glass and a clad covering the core. The material of the clad is not particularly limited, but a material having a refractive index smaller than that of the core is preferable from the viewpoint of suppressing laser loss. In the case of a fiber having a two-layer structure, the outer diameter of the fiber is generally 100 to 500 μm, the core diameter is 1 to 15 μm, and the difference in the specific refractive index between the core and the clad is generally 0.2 to 3.5%. However, the present invention is not limited to these, and can be appropriately determined in consideration of the intended use and the like.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these examples.

Tables 1 to 4 show examples and comparative examples of the present invention, respectively.

Each sample was prepared as follows. Ge, Sb, Bi, S, Te, Se, Sn, Fe, Cr, Co, and Pr were mixed so as to have a predetermined composition ratio to obtain a raw material batch. After vacuum exhausting the quartz glass ampoule washed with pure water while heating, the raw material batch was put in and the quartz glass ampoule was sealed with an oxygen burner while vacuum exhausting.

The sealed quartz glass ampoule was heated to 650-800 ° C. at a rate of 10 to 20 ° C./hour in a melting furnace and then held for 6 to 12 hours. During the holding time, the quartz glass ampoule was turned upside down every 2 hours and the melt was stirred. Then, the quartz glass ampoule was taken out from the melting furnace and rapidly cooled to room temperature to obtain a sample.

The obtained sample was subjected to differential thermal analysis, and it was confirmed whether or not it was vitrified from the presence or absence of the glass transition point. In the table, those that are vitrified are indicated by "○" and those that are not vitrified are indicated by "×". Further, the light transmittance at a thickness of 2 mm was measured for each sample with a spectrophotometer, and a 50% transmitted wavelength in the infrared region having a wavelength of 1 to 12 μm was determined. Further, the excitation wavelength and the emission wavelength in the infrared region of each sample were measured with a spectrophotometer.

The obtained chalcogenide glass was processed into a rod-shaped preform, and then the preform was drawn while heating at 200 to 500 ° C. under an inert atmosphere to form a fiber. Those that could be molded into a fiber shape were marked with "○", and those that could not be molded due to crystallization during molding were marked with "x".

As is clear from the table, the samples of Examples 1 to 38 were vitrified and could be formed into a fiber shape. Furthermore, the 50% transmission wavelength was 10 μm or more, showing good light transmittance, and light emission was confirmed in the infrared region with a wavelength of 1 μm or more.

On the other hand, the samples of Comparative Examples 1 to 5 were not vitrified. The light transmittance was almost 0% in the wavelength range of 1 to 12 μm, and no light emission was confirmed.

Claims (9)

It is characterized by containing Ge 0 to less than 20%, Sb 21.3 to 40%, Bi 0 to 20%, S + Se + Te 50 to 75 %, and transition metal element 0.01 to 10% in mol%. Calcogenide glass. It is characterized by containing Ge 2 to 20%, Sb 21.3 to 35%, Bi 1 to 20%, S + Se + Te 55 to 75%, and transition metal element 0.01 to 5% in mol%. The chalcogenide glass according to claim 1. The chalcogenide glass according to claim 1 or 2, further comprising Sn 0 to 20% in mol%. The chalcogenide according to any one of claims 1 to 3, wherein the transition metal element is at least one selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and rare earth elements. Glass. The fourth aspect of claim 4, wherein the rare earth element is at least one selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. The described chalcogenide glass. The chalcogenide glass according to any one of claims 1 to 5, which is substantially free of As, Cd, Tl and Pb. A light emitter comprising the chalcogenide glass according to claim 1. The light emitting body according to claim 7, which is in the form of a fiber. A laser medium comprising the light emitting body according to claim 7 or 8.