WO2008111681A1 - Optical glass and process for producing the same - Google Patents

Abstract

An optical glass which has a refractive index (nd) of 1.7 or higher and an Abbe's number (νd) of 40 or larger and contains at least 30% Ln2O3 ingredient (Ln is one or more elements selected among Y, La, and Gd) in terms of oxide amount in mass% and in which the content of As2O3 and Sb2O3 ingredients is less than 0.1%. The proportion of the Gd2O3 content to the total content of the Ln2O3 ingredient (Gd2O3/Ln2O3) is preferably 20% or lower. The glass preferably contains a B2O3 ingredient as an essential component and has a liquidus temperature of 1,100°C or lower.

Description

 TECHNICAL FIELD The present invention relates to an optical glass and a method for producing the same.

 In the fields of biology and medicine, observe the fluorescence emitted from the observation object by irradiating the observation object with excitation light such as ultraviolet rays in order to observe biological tissues, cells, genes, bacteria, etc. In recent years, techniques for detecting weak fluorescence emitted from a phosphor adsorbed to a specific site such as a very small amount of bacteria or cells have been actively researched. In particular, in recent years, there has been a growing need for a high refractive index and low dispersion glass as an optical glass used in such a microscope.

 By the way, the optical glass used for the objective lens of the microscope used for such observation and measurement may be excited by ultraviolet rays to generate fluorescence. Since the fluorescence from this glass becomes noise when observing the fluorescence emitted from the observation object, it has been regarded as a problem.

 Therefore, an optical glass with low intensity of fluorescence generated by excitation of ultraviolet rays or the like is required. In particular, a high refractive index low dispersion optical glass disclosed in Japanese Patent Application Laid-Open No. Sho 5 6-4 1 8 5 0. In fact, there is almost no consideration for reducing the fluorescence intensity. Therefore, at present, the existing high-refractive index low-dispersion optical glass is used for observing or measuring weak fluorescence generated from an observation object by irradiating the observation object with excitation light such as ultraviolet rays. It cannot be used for optical instruments (for example, fluorescence microscopes).

On the other hand, Japanese Patent Application Laid-Open No. 2 00 0-1 2 8 5 6 9 discloses a low fluorescence optical glass having high refractive index and low dispersibility. However, the glass compositions which are specifically disclosed in the above publication, although by ultraviolet excitation fluorescence intensity is low, since both contain a large amount of _{Y b 2 0 3, 9 7} 0 nm before and after the infrared region Has the disadvantage that the light transmittance at is extremely poor.

Japanese Laid-Open Patent Publication No. 2 0 02-1 2 8 5 39 discloses a low fluorescence optical glass having high refractive index and low dispersibility. However, the glass compositions which are specifically disclosed in the above publication, although by ultraviolet excitation fluorescence intensity is low, because it contains a large amount of G d ₂ 0 _3, that the liquidus temperature is high and difficult to stabilize production There are drawbacks. Furthermore, due to Y b ₂ O 3 contained as an essential component, there is a drawback that the light transmittance in the infrared region is extremely poor. Japanese Patent Application Laid-Open No. 11-110 6 2 3 3 discloses a low fluorescent glass which is free of Sb ₂ O ₃ and has a specified Pt amount. However, the glass of the composition specifically disclosed in the above publication has the disadvantage that it cannot be used in a high-precision optical system, although it has low fluorescence intensity due to ultraviolet excitation, and bubbles are not removed and the internal quality is poor. Furthermore, because of its low refractive index and low dispersion, it is not possible to obtain a glass intended for this development. DISCLOSURE OF THE INVENTION The object of the present invention is to provide an optical constant having a high refractive index and low dispersion, that is, a refractive index (nd) exceeding 1.70 and an Abbe number (vd) of 40 or more in view of the actual state of the prior art. Optical glass with low liquidus temperature, excellent light transmittance in the infrared region, low intensity of fluorescence generated upon irradiation with ultraviolet rays, etc., and excellent internal quality There is to do.

The first configuration of the present invention that achieves the above object is that the refractive index (nd) is 1.7 or more and the Abbe number is (vd) has 40% or more, and is mass% on the basis of oxide, and n ₂ 0 ₃ component (L n is one or more selected from Y, La, G d) 30% An optical glass containing the A s ₂ 0 ₃ and S b ₂ O a components in an amount of less than 0.1%.

The second aspect of the present invention, the L n ₂ 0 ₃ content of G d ₂ 0 ₃ to the total content of the component _{(G d 2 0 3 / L} n 2 0 3) ratio of 2 0% or less There have containing a as an essential component B ₂ 0 ₃ component, Ru optical glass der of the structure 1, wherein the liquidus temperature of less than 1 1 0 0 ° C.

 The third configuration of the present invention is the mass% based on oxide.

B ₂ O 3 2 5-40% and

L a 2 O 3 3 5-5 0% and

S i O ₂ 0-5% and / or

Y ₂ 0 ₃ 0 to 15% and / or

G d ₂ O a 0 to: 10% and NO or

N b 2 O 5 0 to: 10% and NO or

ZrO2 0 to: 10% and or

ZnO 0 to: 10% and / or

 RO 0 to: 10% (one or more selected from the group consisting of I iMg, C a, S r and B a) and / or

A s 2 O 3 + S b ₂ O a 1 5 ppm ^ A

Containing each component in the range of

The optical glass having the constitution 1 or 2 characterized by not containing Y b ₂ 0 ₃ .

Fourth configuration of the present invention, P t content in the glass is more than the total content of A s ₂ 0 ₃ and S b ₂ 0 ₃ in the glass, the fluorescence intensity due to ultraviolet excitation is reduced the The optical glass according to any one of configurations 1 to 3.

 The fifth configuration of the present invention is as follows. In the glass of 100 ml shown in Table 1 of “Optical Glass Foam Measurement Method”, JOG IS 1 2-1 9 94, Japan Optical Glass Industry Association Standard The sum of the cross-sectional areas of the bubbles is of class 1 to 3, and is shown in Table 1 of “Measurement Method of Foreign Objects in Optical Glass” 1 JOG IS 1 3— 1 9 9 4 1 The total cross-sectional area of foreign objects in the 0 m 1 glass is of class 1 to 3, and the Japan Optical Glass Industry Standard JOG IS 1 1— 1 9 7 5 “Measurement method of optical glass striae” The optical glass according to any one of the constitutions 1 to 4, wherein the degree of striae shown in Table 2 is a grade 1 to 3.

 The sixth configuration of the present invention is characterized in that the relative fluorescence intensity of the fluorescence spectrum in the wavelength range of 400 to 700 nm excited by light of 37. 7 nm is less than 0.4. The optical glass according to any one of the above constitutions 1 to 5.

According to a seventh configuration of the present invention, there is provided an optical glass containing 30% or more of an L n ₂ O ₃ component (L n is one or more selected from Y, La and G d), A method for producing an optical glass for a fluorescence microscope by melting and forming in a crucible made of an alloy comprising a platinum group element or a platinum group element and other elements, wherein A s ₂ 0 ₃ and S b ₂ 0 ₃ It is a production method characterized by substantially not adding components.

By adopting the above configuration, in a high refractive index and low dispersion optical glass, the liquidus temperature is low, the light transmittance is excellent in the infrared region, and the intensity of fluorescence generated upon irradiation with ultraviolet rays is small. Further, it is possible to provide an optical glass having excellent internal quality. BEST MODE FOR CARRYING OUT THE INVENTION The components that can be contained in the optical glass of the present invention will be described. Hereinafter, unless otherwise specified, the content of each component is expressed in mass% based on oxide. In the present specification, the “oxide standard” means an oxide, carbonate, glass used as a raw material for the glass component of the present invention. Assuming that acid salts etc. are all decomposed and transformed into oxides when melted, the total weight of the product oxide is 100 mass. This is a composition in which the content of each component contained in the glass is expressed when / ₀ .

In the glass having the above composition, the B ₂ O 3 component is an essential component effective for lowering the liquidus temperature in the optical glass of the present invention. However, if the amount is too small, the effect becomes insufficient. There is a disadvantage that the meltability tends to deteriorate. If the content is too large, it is difficult to obtain the desired optical constant. Therefore, in order to obtain the desired glass, it is preferably 40%, more preferably 37%, most preferably 35%, and preferably 25%, more preferably 27%. Most preferably, 30% can be contained as a lower limit. In the glass having the above composition, the L n ₂ O ₃ component (L n is one or more selected from Y, La, and G d forces) is kept at a low liquidus temperature in the optical glass of the present invention. It is an essential component effective for increasing the refractive index, but if its amount is too small, the effect is unlikely to be sufficient. On the other hand, if the amount is too large, there is a disadvantage that the liquidus temperature tends to be high. Therefore, in order to make it easy to obtain the target glass, it is preferably 50%, more preferably 48%, most preferably 47%, and preferably 30%, more preferably 35%. Most preferably, 40% can be contained as a lower limit.

Of the L n ₂ 0 ₃ components, the La ₂ 0 ₃ component is an effective component for increasing the refractive index while maintaining low dispersion without increasing the liquidus temperature. There is a disadvantage that it becomes difficult to obtain the optical constant. On the other hand, if the amount is too large, the liquidus temperature tends to increase. Therefore, in order to obtain the target glass, it is preferably 35%, more preferably 38%, most preferably 40% as the lower limit, preferably 50%, more preferably 47%, Most preferably, it can contain up to 45%.

The ₂ 0 ₃ component is an effective component for increasing the refractive index while maintaining low dispersion. However, if the amount is too large, there is a disadvantage that undissolved substances are likely to occur during glass melting. Therefore, in order to obtain the target glass, it is preferable to contain 15% as an upper limit, preferably 15%, more preferably 13%, and most preferably 11%.

The G d ₂ 0 ₃ component is an effective component for increasing the refractive index while maintaining low dispersion, and adding a small amount is effective in lowering the liquidus temperature, but conversely if the amount is too large. There is a disadvantage that the liquidus temperature tends to increase. Therefore, in order to obtain the target glass, the upper limit is preferably 10%, more preferably 7%, and most preferably 5%.

Note that the ratio of the content of the G d ₂ 0 ₃ component in the L n ₂ 0 ₃ component is an important factor for maintaining good glass stability. When the total content of L n _{20 3} components is 100%, it is preferably 20% or less, more preferably 18% or less, and most preferably 15% or less.

Y b ₂ O 3 is not preferably contained because it tends to cause unnecessary absorption in the range of 970 nm.

The S i ○ ₂ component is an optional component effective in improving the chemical durability in the optical glass of the present invention. However, if the amount is too large, undissolved or devitrification tends to increase. There is a profit. Therefore, the upper limit is preferably 5%, more preferably 4%, and most preferably 3%.

N b ₂ 0 ₅ component is an optional component effective to increase the refractive index without lowering the transmittance, the amount of that is too large dispersion tends to increase. Therefore, in order to obtain the target glass, the upper limit is preferably 10%, more preferably 5%, and most preferably 3%.

The Zr 0 ₂ component is an optional component effective for improving the chemical durability of the glass and increasing the refractive index. However, if the amount is too large, there is a disadvantage that the liquidus temperature is easily increased. Therefore, in order to obtain the target glass, the upper limit is preferably 10%, more preferably 9%, and most preferably 8%.

Z n O component is an optional component effective for improving chemical durability, but its amount is large. If it is too much, the liquidus temperature becomes high and the target optical constant is difficult to obtain. Accordingly, the upper limit is preferably 10%, more preferably 5%, and most preferably 3%.

 RO component (R is one or more selected from the group consisting of Mg, Ca, Sr, and Ba) is an optional component that is effective for making homogeneous glass to facilitate the melting of glass materials. However, if the amount is too large, there is a disadvantage that the glass tends to devitrify. Accordingly, the upper limit is preferably 10% or less, more preferably 5% or less, and most preferably 3%.

 Among RO components, MgO and CaO are effective optional components for improving the chemical durability of glass. However, if the amount is too large, devitrification of the glass tends to increase. There is a disadvantage. Therefore, in order to obtain the target glass, the upper limit is preferably 10%, more preferably 5%, and most preferably 3%. SrO and BaO are optional components effective for obtaining a homogeneous glass because they facilitate melting of the glass raw material, but if the amount is too large, there is a disadvantage that the glass tends to devitrify. . Therefore, in order to obtain the target glass, the upper limit is preferably 10%, more preferably 5%, and most preferably 3%. It should be noted that none of the R O components may be contained.

 The optical glass of the present invention may contain Pt as an impurity. It is known that the mixing of Pt in the glass causes the disadvantage of increasing the fluorescence intensity due to ultraviolet excitation, so the amount of Pt in the glass is preferably 15 ppm or less. More preferably, it is 10 ppm or less, and most preferably 5 ppm or less. In order to reduce the amount of Pt in the glass, when melting the raw material, for example, melting using a crucible other than platinum, such as a quartz crucible, for example, in melting of the caret in optical glass production, It is preferable to take measures such as lowering as much as possible.

S b ₂ 〇 ₃ and A s ₂ 0 ₃ component is usually used as a defoaming agent in the optical glass, the glass containing small amount of P t, there is not benefit fluorescence by ultraviolet excitation further enhanced easy Therefore, the total amount of S b ₂ 0 ₃ and a s ₂ 0 ₃ component, preferably 1 5 ppm or less, and more preferably not more than 1 0 ppm, does not contain the most preferred.

In particular, in the composition system of the present glass, Pt or Pt alloy is unavoidably used as part of the production equipment in order to eliminate bubbles, devitrification, and striae. Nevertheless, the total content of S b ₂ O ₃ and As ₂ O 3 is less than the content of P t, that is, by maintaining the relationship P t> S b ₂ 0 ₃ + AS 2 0 ₃ It is possible to produce a glass with few foreign matters and striae and low fluorescence.

 In the optical glass of the present invention, the foam is preferably class 1 to 3 based on Japan Optical Glass Industry Association Standard JOGIS 1 2-1 9 94 "Method for measuring foam of optical glass", class 1 to 2 More preferably, the grade 1 is most preferable.

 In the optical glass of the present invention, the foreign matter is preferably class 1 to 3 based on Japan Optical Glass Industry Association Standard JOGIS 1 3-1 9 94 4 "Measurement Method of Foreign Substances in Optical Glass", and is Class 1 or 2 More preferably, the grade 1 is most preferable.

 In the optical glass of the present invention, the striae is preferably class 1 to 3 based on the Japan Optical Glass Industry Association Standard JOGIS 1 1-1 975 “Measurement method of striae of optical glass”, class 1 to 2 Is more preferred, and is most preferably grade 1.

 Next, components that should not be contained in the optical glass of the present invention will be described. The lead component is not only a problem that it is a die-casting component with the mold at the time of precision press molding and glass production, but also from the cold processing of glass such as polishing and the disposal of glass. Since measures are necessary and there is a problem that it is a component with a large environmental load, it is preferably not contained in the optical glass of the present invention.

 Both the cadmium and the tritium components are harmful components to the environment and have a very large environmental load, so it is preferable not to include them in the optical glass of the present invention.

If P ₂ 0 ₅ is contained in the optical glass of the present invention, the devitrification resistance is likely to be deteriorated, so that it is preferably not contained. T e 0 ₂ component, and a platinum crucible, when the portion in contact with the molten glass is melted the glass raw materials Toruso soluble are formed of platinum, a portion where tellurium and platinum are alloyed, became alloy heat Therefore, it is preferable that the optical glass of the present invention does not contain it.

 Further, in the optical glass of the present invention, coloring components such as V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Eu, Nd, Sm, Tb, Dy, Er, etc. Is preferably not contained. In this specification, “does not contain” means that it is not contained artificially unless it is mixed as an impurity.

The composition of the glass composition of the present invention is mass. Although it is expressed by / ₀ , it cannot be expressed directly in the description of mo 1%, but the composition expressed by mo 1% of each component present in the glass composition satisfying various properties required in the present invention is The oxide conversion composition has the following values.

B ₂ O 3 4 5-6 5% and

L a 2 o ₃ 1 0-30 0% and

 S i o 2 0 to l o% and Z or

 2 o 3 0 to 15% and or

G d 2 o ₃ 0 to 10% and or

N b 2 o ₅ 0-5% and / or

 Z r o 2 0 to 10% and / or

 Z n o 0 to 15% and / or

 RO 0 to: 1 5% (one or more selected from the group consisting of I ^ iMg, C a, S r, B a) and / or

A s ₂ O 3 + S b 2 O 3 0 to 0.0 5%

 Next, the physical properties of the optical glass of the present invention will be described.

 The optical glass of the present invention preferably has a low fluorescence intensity so as to be particularly advantageous when used as a fluorescence microscope. Specifically, using the glass used as a standard sample in the “Measurement Method of Fluorescence of Optical Glass (JOG IS— 1 9 7 5)” established by the Japan Optical Glass Industry Association, Was measured at a wavelength of 36 7 nm, and the fluorescence spectrum was measured in the wavelength range of 400-700 m, and the highest fluorescence peak height in this wavelength range was measured for each glass. The value of relative fluorescence intensity is preferably 0.4 or less, more preferably 0.3 or less when the peak height of the standard sample is evaluated as a relative intensity ratio when the peak height is 1. Most preferably, it is 0.2 or less.

 Since the optical glass of the present invention is assumed to be used in a fluorescence microscope, it is preferable that light emitted from the sample is transmitted evenly. In particular, since many conventional high refractive index and low dispersion glasses have an absorption peak in the region of 70 to 110 nm, it is preferable that such absorption characteristics are not provided.

 The optical glass of the present invention preferably has a refractive index of 1.7 or more. This is because it is advantageous in terms of design when used with a fluorescent microscope lens. Therefore, preferably

1. 7 2 or more, most preferably 1. 75 or more.

 The optical glass of the present invention preferably has an Abbe number of 40 or more. This is because it is advantageous in design to reduce chromatic aberration. Therefore, it is preferably 43 or more, and most preferably 45 or more.

 The optical glass of the present invention preferably has a lower liquidus temperature. In particular, in order to realize stable production, the liquidus temperature is preferably 1 100 ° C. or lower, more preferably 1 0 90 ° C. or lower, and 1 1 80 ° C. or lower. Most preferred.

In this specification, “liquid phase temperature” means using a general melting furnace, melting a 50 cc glass sample with a platinum crucible, holding it at an arbitrary temperature for 5 hours, and taking it out. It means the lowest temperature at which no crystals are observed by visually observing the presence or absence of glass crystals. Examples of the present invention will be described below, but the present invention is not limited to these examples. The content of each component specified in the table below is the mass based on oxide. It shall be expressed as / ₀ .

 Examples (N o. L to N o. 6) and comparative examples ((N o. A to N o. D) of the glass of the present invention shown in the table are oxides, hydroxides, carbonates, nitrates. Ordinary optical glass raw materials such as the above are weighed so as to have the composition ratio of each example, mixed, put into a platinum crucible, and 1 00 0-1 4 00 ° depending on the meltability of the composition It was obtained by melting, clarifying, stirring and homogenizing for 3 to 10 hours at C. Then, it was obtained by pouring into a mold, etc., and cooling it slowly, as well as a platinum crucible. An alloy crucible made of another element may be used.

 The refractive index (n d) and Abbe number (v d) were measured for the optical glass obtained at a slow cooling rate of 125 ° C / h.

 To measure the liquidus temperature, use a general melting furnace, melt a 50 cc glass sample with a platinum crucible, hold it at an arbitrary temperature for 5 hours, and then take it out to check for glass crystals. The lowest temperature at which no crystal was observed was determined by visual observation.

Fluorescence intensity is measured using the flint glass used as a standard sample in the “Measurement Method of Fluorescence of Optical Glass (JOG IS — 1 9 7 5)” established by the Japan Optical Glass Industry Association. The sample was excited at a wavelength of 36. 7 nm, the fluorescence spectrum was measured in the wavelength range of 400-700 nm, and the highest fluorescence peak height in this wavelength range was measured. The peak height of the glass was evaluated by the relative intensity ratio when the peak height of the standard sample was 1.

 Bubbles were measured based on the Japan Optical Glass Industry Standard JOG IS 1 2 — 1 9 9 4 “Measurement method of bubbles in optical glass”.

 The measurement of the foreign material was performed based on the Japan Optical Glass Industry Association standard JOG IS 1 3-1 9 94 “Measurement method of foreign material on optical glass”.

 The striae was measured based on the Japan Optical Glass Industry Standard JOG IS 1 1 _ 1 9 7 5 “Measurement method of striae of optical glass”.

Absorption at 7 00 to 1 100 nm is determined by the spectral transmission including reflection loss by irradiating light in the range of 70 0 to 1 100 nm in a 10 mm thick glass sample that has been face-polished. A rate curve was created, and the presence or absence of absorption in this range was judged from the shape.

【table 1】

 Example 1 Example 2 Example 3 Example 4 Example 5

S i0 ₂ 2.65 2.60 2. 45 2. 60 2. 62

B ₂ 0 ₃ 31.22 31.24 29. 47 31. 24 31. 53

A1 ₂ 0 ₃

Y ₂ 0 ₃ 10.69 10.70 14. 20 10. 80

La ₂ 0 ₃ 45.32 41.84

Gd ₂ 0 ₃ 3.50 5. 66

Yb ₂ 0 ₃

Ti0 ₂

Zr0 ₂ 6.60 6.60 6. 22 6. 60 6. 66

Nb ₂ 0 ₅ 1.62 1.62 1. 53 1. 62 1. 63

Ta ₂ 0 ₅

wo ₃

 o

 ZnO 0.90 0.90 0. 85 0. 90

 gO

 CaO

 SrO 1.00 1.00 0. 94 1. 00 1. 01

 0 0

 BaO

Li ₂ 0

Na ₂ 0

K ₂ 0

Sb ₂ 0 ₃

As ₂ 03

total 100.00 100.00 100. 00 100. 00 100. 00

Pt (ppm) 3.90 4.00 4. 50 4. 20 3. 50 n _d 1.77 1. 77 1. 79 1. 77 1. 77 vd 49.50 49. 40 48. 9 49. 4 49. 6 Foam evaluation results (

 1 1 1 1 1 grade)

Foreign object evaluation

 1 1 1 1 1 Fruit (Class)

Striae evaluation results.

 1 1 1 1 1 Fruit (Class)

Relative fluorescence intensity

 0.2 or less 0.2 or less 0.2 or less 0.2 or less 0.2 or less Degree

Liquidus temperature (° C

 (1050 1030 1030 1060 1040)

 700 ~ 1100nm

表に見られるとおり、 本発明の実施例の光学ガラス （N o . l〜N o . 6) は、 いず れも、 所望範囲内の屈折率及びアッベ数、 液相温度、 蛍光強度及び内部品質を有してい た。 None None None None None Absorption

As can be seen from the table, the optical glasses (N o .l to N o .6) of the examples of the present invention all have the refractive index and Abbe number within the desired range, the liquidus temperature, the fluorescence intensity and the internal Had quality.

The fluorescence intensity is lower than that of the conventional comparative example No. A. Glass Further Comparative Example B, Oite is and C, although the fluorescence intensity is small because it contains a large amount of G d ₂ 〇 _3, on liquidus temperature less stable glass high to satisfy the internal quality I could not get it. In B and C, absorption was observed at a wavelength of around 970 nm. Therefore, it is not suitable as the optical glass of the present invention including the use of a fluorescence microscope. Further, in Comparative Example D, although the fluorescence intensity was small, the liquidus temperature was high, and a glass satisfying the internal quality (bubbles) could not be obtained. Industrial Applicability The low-fluorescence optical glass according to the present invention has a refractive index (nd) exceeding 1.70 in the specific composition range of the B ₂ O 3 -L n ₂ O 3 system, and an Abbe number. (V d) has an optical constant of 40 or more, low liquidus temperature, excellent light transmittance in the infrared region, low intensity of fluorescence generated when irradiated with ultraviolet rays, etc., and internal quality Because it is excellent, it is extremely useful especially for optical systems for fluorescent microscopes.

Claims

The scope of the claims 1. Refractive index (nd) is 1.7 or more, Abbe number (V d) is 40 or more, n ₂ O 3 component in mass% of oxide basis (L n is Y, La, G 1 or 2 or more selected from d), and the content of As ₂ 0 ₃ and S b ₂ O 3 components is less than 0.1%. 2. The ratio of the content of G d ₂ 0 ₃ to the total content of n ₂ 0 ₃ (G d ₂ 0 ₃ / L n ₂ O a) is 20% or less, and B ₂ 0 as an essential component _2. The optical glass according to claim 1, comprising _three components and having a liquidus temperature of 11 ° C. or lower. 3. By mass% based on oxide B ₂ O 3 2 5 to 40% and L a 2 o ₃ 3 5 to 50%  S i o 2 0-5% and / or Y ₂ o 3 0 to 15% and Z or G d 2 o ₃ 0 to 1 ◦% and / or N b 2 o ₅ 0 to 10% and Z or  Z r o 2 0 to 10% and or  Z n o 0 to 10% and / or  RO 0 to: 10% (one or more selected from the group consisting of I ¾Mg, Ca, Sr, Ba) and Z or A s ₂ O a + S b 2 O a 1 5 ppm or less Containing each component in the range of Claim 1 or 2 of the optical glass characterized in that it contains no Y b ₂ 0 _3. 4. The amount of Pt contained in the glass is greater than the total content of As ₂ O 3 and S b ₂ O 3 in the glass, and the fluorescence intensity due to ultraviolet excitation is reduced. Optical glass of crab  5. Japan Optical Glass Industry Association Standard J OG IS 1 2— 1 9 94 The total sum of the cross-sectional areas of bubbles in 100 ml glass shown in Table 1 of “Measurement Method of Bubbles in Optical Glass” 1 to 3, and in the 100 m 1 glass shown in Table 1 of “Measurement Method for Foreign Objects on Optical Glass”, JOG IS 1 3— 1 9 94, Japan Optical Glass Industry Association Standard The sum of the cross-sectional areas of the foreign materials is grade 1 to 3, and is shown in Table 2 of “Optical glass striae measurement method” JOG IS 1 1— 1 9 7 5 The optical glass according to any one of claims 1 to 4, wherein the degree of striae is grade 1 to 3.  6. Fluorescence microscope optics, characterized in that the relative fluorescence intensity of the fluorescence spectrum in the wavelength range from 400 to 700 nm excited by light at 36 nm is less than 0.4 6. The optical glass according to claim 1, which is used in a system. 7. An optical glass material containing 30% or more of an Ln ₂ O 3 component (Ln is one or more selected from Y, La, and Gd), a platinum group element or a platinum group element And an optical glass for a fluorescence microscope by melt molding in a crucible made of an alloy comprising other elements, wherein the components of As s ₂ 0 ₃ and S b 2 0 ₃ are added to the raw material of the optical glass. A manufacturing method characterized by substantially not adding.