JPH07126036A - Glass for near infrared transmitting black filter - Google Patents

Abstract

PURPOSE:To provide glass for a near IR transmitting black filter, containing oxides glass and a specific coloring component, thereby having sharp spectral transmitting properties and improved in chemical durability. CONSTITUTION:This glass for a near IR transmitting black filter contains 0.2-3.0wt.% Cr2O3 and 0.2-4.5wt.% CoO as coloring components so as to afford 0.7-3.0 weight ratio Cr2O3/CoO in 100wt.% oxide glass composed of 60-75wt.% SiO2, 0-15wt.% B2O3, 0-10wt.% Al2O3, 0-10wt.% BaO, 0-10wt.% CaO, 0-10wt.% SrO, 0-10wt.% MgO, 0-20wt.% total amount of BaO, CaO, SrO and Mgo, 0-5wt.% ZnO, 0-10wt.% TiO2, 0-5wt.% ZrO2, 0-20wt.% Na2O, 0-20wt.% K2O, 0-5wt.% Li2O, 12-25wt.% total amount of Na2O, K2O and Li2O, 0-1wt.% total amount of As2O3 and Sb2O3 and 0-5wt.% sum total of fluorides expressed in terms of F substituting a part or all of one or two or more oxides of the respective metallic elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a glass that absorbs visible and far infrared regions and transmits only near infrared region, especially only near the wavelength of semiconductor lasers, and has sharp transmittance as a filter for semiconductor lasers and the like. The present invention relates to a glass for a near-infrared transparent black filter, which has good chemical durability and does not require a coloring step such as heat treatment and is suitable for stable production.

[0002]

2. Description of the Related Art In recent years, the environmental conditions under which electronic components such as semiconductor lasers are used have become more severe, and it has been desired that the filter glass used for them should have better chemical durability. CdS-CdSe which is a colored glass with colloid as a conventional near infrared transmission filter glass
System glass and Mn- which is colored glass with colored ions
It is roughly classified into Cr-based glass. The CdS-CdSe type glass requires a heat treatment step for precipitating a colloid after melting and cooling the glass, and thus has the desired spectral transmittance for the first time, and thus does not only require the heat treatment step. In addition, since the volatilization of S, Se, etc. is intense during the melting process, it is difficult to obtain a homogeneous glass, and uneven coloring occurs during heat treatment due to the inhomogeneity of the glass, making it difficult to obtain a high-quality glass with a constant transmittance. Not suitable for stable production.
Also, this type of glass generally has poor chemical durability,
It does not meet the requirements of recent years. Further, Mn-Cr glass can be produced relatively stably and has good chemical durability, but it is inferior in spectral transmittance and sharpness.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a sharp spectral transmittance as a filter that transmits near infrared rays, particularly near the wavelength of a semiconductor laser. Another object of the present invention is to provide a glass for near-infrared transmissive black filters, which has excellent chemical durability, does not require a coloring step such as heat treatment, and is suitable for stable production.

[0004]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has found that when Cr ₂ O ₃ and CoO are introduced into an oxide glass, they are The inventors have found that a black glass that absorbs the region and far infrared and has a sharp transmittance for near infrared, especially near the wavelength of a semiconductor laser can be easily and stably obtained, and has completed the present invention. . That is, the glass composition according to the present invention is such that, with respect to 100% by weight of the oxide glass, 0.2% to 3.0% by weight of Cr ₂ O ₃ and CoO are used as coloring components.
0.2-4.5%, but by weight ratio Cr ₂ O ₃ / Co
It is characterized by containing O = 0.3-4.0.

Next, the reason why the composition range of each component is limited as described above will be described. Cr ₂ O ₃ component is 0.2% by weight based on 100% by weight of oxide glass as a basic composition.
If less than, a peak appears near 350 nm,
If it exceeds 3.0%, the sharpness on the short wavelength side deteriorates.
If the CoO component is less than 0.2% by weight, the infrared transmittance tends to increase, and if it exceeds 4.5%, the sharpness on the short wavelength side deteriorates. However, in terms of weight ratio, when Cr ₂ O ₃ / CoO is less than 0.3, a peak that transmits around 350 nm appears, and when it exceeds 4.0, the transmission tendency in the infrared region increases.

Further, the basic composition range of the oxide glass, which has good chemical durability and is more preferable, is as follows:
₂ 60-75%, B ₂ O ₃ 0-15%, Al ₂ O ₃ 0
-10%, BaO 0-10%, CaO 0-10%,
SrO 0-10%, MgO 0-10%, but Ba
O + CaO + SrO + MgO 0-20%, ZnO0
5%, TiO ₂ 0-10%, ZrO ₂ 0-5%, Na
₂ O 0-20%, K ₂ O 0-20%, Li ₂ O 0
5%, provided that Na ₂ O + K ₂ O + Li ₂ O 12-25
%, As ₂ O ₃ + Sb ₂ O ₃ 0 to 1% and a total of 0 to 5% as F of a fluoride substituted with a part or all of one or more oxides of the above metal elements. Composition.

Furthermore, the near-infrared range for a coloring component, especially showing the preferred composition range which transmits near the semiconductor laser wavelength sharper respect basic composition 100 wt%, by weight%, Cr ₂ O ₃ component is 0 0.5-3.0%, CoO component 0.8-3.5%, provided that Cr ₂ O ₃ / Co by weight ratio.
It is a composition containing O = 0.7 to 3.0. In addition to these, MnO ₂ , Fe ₂ O ₃ , CeO ₂ , V ₂ O ₅ , N
The d ₂ O ₃ component can be introduced up to 1.0% for the purpose of adjusting the transmission peak and the like.

[0008]

EXAMPLES Table 1 shows examples of compositions (No. 1 to No. 7) of the glass according to the present invention, and each wavelength of the face-to-face polished sample (thickness 1.0 mm) of the glass shown in Table 1 (600
Table 2 shows the transmittance% at 1 to 1200 nm). In addition, the example Nos. 1, No. 3 and No. 5,
And Comparative Example A (CdS-CdSe based filter glass) and Comparative Example B (Mn-Cr based filter glass)
FIG. 1 shows a transmittance curve of a glass surface-polished sample (thickness: 1.0 mm).

[0009]

[Table 1]

[Table 1]

[0010]

[Table 2]

[Table 2]

As can be seen in Table 2 and FIG. 1, No. 3 and No. The glass of No. 5 is 800 to 900 as compared with the glasses of Comparative Examples A and B.
It has a sharp spectral transmittance with a peak in the vicinity of nm, and is suitable for use as a filter for semiconductor lasers such as Ga-As. Glass No. of another embodiment composition example of the present invention. 2, No. 4, No. 6 and No. 6 Similarly, 7 also exhibits excellent spectral transmittance.

In each of the glasses of the present invention, raw materials such as oxides, carbonates, nitrates and fluorides are appropriately selected so as to obtain a predetermined oxide composition, and the mixed glass raw materials are quartz or Put it in a platinum crucible and put it in about 1250
It can be easily and stably manufactured by melting at 1500 ° C., defoaming with sufficient stirring, and then slowly cooling.

[0013]

As described above, the glass for near-infrared transmitting black filter of the present invention has a visible region by mixing Cr ₂ O ₃ and CoO in a fixed ratio with respect to 100% by weight of the basic composition. As a filter for semiconductor lasers, etc. that absorbs in the far infrared region and transmits in the near infrared region, especially in the vicinity of the wavelength of the semiconductor laser, has sharp transparency, good chemical durability, and a coloring process such as heat treatment. Is suitable as a near-infrared transparent black glass that does not require and is suitable for stable production.

[Brief description of drawings]

FIG. 1 is a composition example No. 1 according to the present invention. 1, No. Three
And No. The figure which shows the transmittance | permeability curve of the glass of 5 and the glass of the comparative example A and the comparative example B.

Claims (3)

[Claims] 1. Cr ₂ O ₃ 0.2 to 3.0% by weight as a coloring component with respect to 100% by weight of oxide glass,
CoO 0.2-4.5%, but by weight ratio Cr ₂
A glass for a near-infrared transmitting black filter, which contains O ₃ /CoO=0.3 to 4.0. 2. The oxide glass is 100% by weight and contains S
iO ₂ 60-75%, B ₂ O ₃ 0-15%, Al ₂ O ₃
0-10%, BaO 0-10%, CaO 0-10
%, SrO 0-10%, MgO 0-10%, provided that BaO + CaO + SrO + MgO 0-20%, Z
_{nO 0~5%, TiO 2 0~10%} , ZrO 2 0~
5%, Na ₂ O 0 to 20%, K ₂ O 0 to 20%, Li
₂ O 0-5%, provided that Na ₂ O + K ₂ O + Li ₂ O 1
2 to 25%, As ₂ O ₃ + Sb ₂ O ₃ 0 to 1%, and a total of 0 to 5 as F as a fluoride substituted with part or all of one or more oxides of the above metal elements. %, The glass for a near-infrared transparent black filter according to claim 1. 3. A coloring component containing 100% by weight of Cr _{2
O 3 0.5~3.0%, CoO 0.8~3.5%} ,
However, the glass for a near-infrared transmitting black filter according to claim 1 or 2, which contains Cr ₂ O _{3 /} CoO = 0.7 to 3.0 in a weight ratio.