CN107162404A - Optical glass and optical element - Google Patents

Abstract

It is the high-refraction low-dispersion optical glass for mold that 1.76 1.80, Abbe number is 47 51 that the present invention, which provides a kind of refractive index,.Optical glass, its percentage by weight composition includes：SiO₂：0 3%；B₂O₃：25 40%；La₂O₃：20 40%；Gd₂O₃：12 25%；ZrO₂：6.5 15%；ZnO：More than 10% but less than or equal to 20%；Ta₂O₅：0 5%；Nb₂O₅：0 5%；Li₂O：0 10%；(Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) it is less than 0.45；Y₂O₃：0 10%；The transition temperature Tg of glass is below 625 DEG C.The present invention makes this glass while desired optical constant is realized by rational component proportion, it is easy to accomplish beneficial to accurate die pressing and the Spectralite with high refractivity and low dispersion with excellent transmitance.

Description

Optical glass and optical element

Technical field

The present invention relates to a kind of optical glass with high-refractivity and low-dispersion characteristic, and by the optics glass The gas preform and optical element of glass formation.

Background technology

For optical glass, refractive index, Abbe number, transmitance are its core photosensitiveness features.Refractive index Determine the basic function of glass with Abbe number, refractive index is the optics that 1.76-1.80, Abbe number are 47-51 Glass belongs to Spectralite with high refractivity and low dispersion, and application of this kind of high-performance glass in optical system can be with Shorten the length of camera lens, improve image quality.

To meet the requirement of optical glass precise compression molding, the transition temperature Tg of optical glass is proposed will Ask.On the premise of identical optical property is realized, how to realize the low Tg temperature of glass and while ensure saturating Cross that rate is excellent, be the target researched and developed at present.CN102050571A disclose a kind of refractive index for 1.77-1.83, Abbe number is 44-51 optical glass having high refractive index, but its Tg temperature is higher, is not suitable for the accurate mould of low cost Pressure.In addition, containing substantial amounts of Ta in the glass ingredient₂O₅, and Ta₂O₅Belong to expensive metal oxide, It is a large amount of to use the cost of material for improving Spectralite with high refractivity and low dispersion, reduce the economy of product. Further, it also contains SnO₂, SnO₂Not only be difficult to melt, easily form impurity in glass, in influence glass Quality and processing characteristics, can also improve the degree of staining of glass, reduce transmitance.Shooting or projection class optical system The optical element of system requires higher to optical glass transmitance, if high-refraction low-dispersion optical glass for mold formation Transmission light transmitted by lens amount is not enough, and the transmitted light flux of optical system can be caused significantly to decline or die-off, influenceed into As quality.

The content of the invention

It is that 1.76-1.80, Abbe number are that the technical problems to be solved by the invention, which are to provide a kind of refractive index, 47-51 high-refraction low-dispersion optical glass for mold, glass Ta in reduction glass ingredient₂O₅While content, The glass has excellent transmitance.

The present invention also provides a kind of gas preform and optical element formed by above-mentioned optical glass.

The technical proposal for solving the technical problem of the invention is：Optical glass, its percentage by weight composition Including：SiO₂：0-3%；B₂O₃：25-40%；La₂O₃：20-40%；Gd₂O₃：12-25%；ZrO₂：6.5-15%； ZnO：More than 10% but less than or equal to 20%；Ta₂O₅：0-5%；Nb₂O₅：0-5%；Li₂O：0-10%； (Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) it is less than 0.45；Y₂O₃：0-10%；The transition temperature Tg of glass is at 625 DEG C Below.

Further, also contain：GeO₂：0-10%；Bi₂O₃：0-10%；Al₂O₃：0-10%；Na₂O：0-10%； K₂O：0-10%；CeO₂：0-1%；Sb₂O₃：0-1%；RO：0-10%, wherein, RO is MgO, CaO, SrO Or the one or more in BaO.

Further, wherein, Al₂O₃：0-5% and/or Na₂O：0-5% and/or K₂O：0-5% and/or GeO₂： 0-5% and/or Bi₂O₃：0-5% and/or CeO₂：0-0.5% and/or Sb₂O₃：0-0.5% and/or RO：0-5%.

Further, wherein, Al₂O₃：0-1% and/or Na₂O：0-1% and/or K₂O：0-1% and/or GeO₂： 0-1% and/or Bi₂O₃：0-1% and/or RO：0-1%.

Further, wherein, (ZrO₂+Y₂O₃)/(Nb₂O₅+Gd₂O₃) it is 0.30-1.50； La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) it is 0.38-0.75；ZnO/(B₂O₃+SiO₂) it is 0.25-0.65.

Further, wherein, B₂O₃：28.5-35% and/or La₂O₃：25-35% and/or Gd₂O₃：14-22% and / or ZrO₂：6.5-10% and/or ZnO：11-16% and/or SiO₂：0-1% and/or Ta₂O₅：0-1% and/or Nb₂O₅：0-1% and/or Y₂O₃：0-7% and/or Li₂O：0-5%.

Further, wherein, B₂O₃：29-32% and/or La₂O₃：27-32% and/or Gd₂O₃：15-20% and/ Or ZrO₂：6.5-8.5% and/or ZnO：11-14.5% and/or SiO₂：0-0.5% and/or Ta₂O₅：0-0.5% And/or Nb₂O₅：0-0.5% and/or Y₂O₃：0.1-5% and/or Li₂O：0-1%.

Further, wherein, (Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) it is less than 0.10；And/or La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) it is 0.45-0.70；And/or ZnO/ (B₂O₃+SiO₂) it is 0.30-0.55； And/or (ZrO₂+Y₂O₃)/(Nb₂O₅+Gd₂O₃) it is 0.48-1.10.

Further, wherein, (Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) it is less than 0.07；And/or La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) it is 0.55-0.65；And/or ZnO/ (B₂O₃+SiO₂) it is 0.30-0.50； And/or (ZrO₂+Y₂O₃)/(Nb₂O₅+Gd₂O₃) it is 0.50-1.0.

Further, glass refraction is 1.76-1.80；The Abbe number of glass is 47-51；Density exists 5.00g/cm³Below.

Gas preform, is made of above-mentioned optical glass.

Optical element, is made of above-mentioned optical glass.

The beneficial effects of the invention are as follows：Do not introduce SnO₂Composition, makes glass transmitance excellent；Reduce Ta₂O₅'s Content, optimizes product cost；By rational component proportion, this glass is set to realize that desired optics is normal Number while, it is easy to accomplish beneficial to accurate die pressing and with excellent transmitance high-refractivity and low-dispersion optics Glass, and the gas preform and optical element formed by the optical glass.

Embodiment

Ith, optical glass

The composition of optical glass of the present invention is described in detail below, the content of each glass ingredient, always contained Amount is such as not particularly illustrated, then is all indicated using weight %, the ratio between content of glass ingredient and total content with Weight is than representing.In addition, in the following description, when mentioning below setting or more than setting, also wrapping Include the setting.

B₂O₃It is glass network formation component, with improving glass fusible and reduce the work of glass transition temperature With.In order to reach the effect above, present invention introduces more than 25% or more B₂O₃, but when its introduction volume exceedes When 40%, then stability, glass can decline, and refractive index declines, it is impossible to obtain the high index of refraction of the present invention. Therefore, B of the invention₂O₃Content be 25-40%, preferred scope is 28.5-35%, and preferred scope is 29-32%.

SiO₂It is also glass former, with B₂O₃The loose chain multi-layered network constituted is different, SiO₂In glass What is formed in glass is silicon-oxy tetrahedron three-dimensional network, very fine and close firm.Such network is added in glass, To loose boron oxygen triangle body [BO₃] network reinforced, and it is become fine and close, so as to lift the high temperature of glass Viscosity.At the same time, the addition of silicon-oxy tetrahedron three-dimensional network, glass network isolation La₂O₃、Nb₂O₅Deng analysis The ability enhancing of brilliant cation and anion, adds crystallization threshold value so that the devitrification resistance of glass can be lifted. If but SiO₂Content it is unconfined increase, dissolving on the one hand can be caused difficult, on the other hand in order to maintain compared with High refractive index and low dispersion, will certainly increase La₂O₃、Gd₂O₃Deng the content of rare earth oxide, SiO₂It is right La₂O₃Solubility it is relatively low, glass devitrification resistance can be caused drastically to decline.Therefore, in the present invention, SiO₂ Content is defined to 0-3%, more preferably preferably 0-1%, 0-0.5%.

La₂O₃It is the necessary component of optical characteristics needed for obtaining the present invention.Work as La₂O₃Content be less than 20% when, It is difficult to required optical characteristics；But when its content is more than 40%, glass devitrification resistance and melting behaviour Deteriorate.Therefore, La of the invention₂O₃Content be 20-40%, preferred scope is 25-35%, more preferably Scope is 27-32%.

Gd₂O₃Be obtain optical glass having high refractive index active ingredient, the present invention in pass through Gd₂O₃With La₂O₃Altogether Deposit, the stability to form glass can be improved, but work as Gd₂O₃When content is less than 12%, the effect above is not obvious； If its content is more than 25%, the reduction of glass devitrification resistance forms the bad stability of glass.Therefore, The Gd of the present invention₂O₃Content be 12-25%, preferred scope is 14-22%, more preferably scope be 15-20%.

The component of the high refractive low dispersive effect of the present invention preferably also introduces Y₂O₃, the meltbility, resistance to of glass can be improved Increased devitrification resistance, while can also reduce devitrification of glass ceiling temperature, if but its content more than 10%, the stabilization of glass Property, devitrification resistance reduction.Therefore, Y₂O₃Content range is 0-10%, and preferred scope is 0-7%, more preferably 0.1-5%.

La₂O₃、Gd₂O₃And Y₂O₃In, to improving glass refraction and maintaining the maximum group of stability, glass effect It is La to divide₂O₃.If but La is used only in the optical glass of the present invention₂O₃, then it is difficult to ensure that sufficient stabilization Property.Therefore, La in the present invention₂O₃The introduction volume of component is relatively more, and makes La₂O₃And Gd₂O₃Coexist； Or preferably make La₂O₃、Gd₂O₃And Y₂O₃Coexist；More preferably La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) scope be 0.38-0.75, further preferred La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) scope be 0.45-0.70, further It is preferred that La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) scope be 0.55-0.65, can obtain with excellent stabilization The glass of the high-refractivity and low-dispersion of property, while glass not easy coloring.

Nb₂O₅There is fabulous effect to improving glass refraction reduction liquidus temperature, it may have improve the anti-of glass The effect of crystallization and chemical durability.If its content is more than 5%, glass dispersion is improved, it is impossible to reached The optical characteristics of glass of the present invention.Therefore, Nb₂O₅Content range be 0-5%, preferred scope is 0-1%, more Preferred scope is 0-0.5%.

Ta₂O₅With the effect for improving refractive index, while it is better than Nb to the effect for maintaining the low dispersion of glass₂O₅, But compared with other components, Ta₂O₅Price is very expensive, therefore the angle of the invention from practical and cost Consider, reduce its usage amount.The Ta of the present invention₂O₅Content is 0-5%, and preferred scope is 0-1%, more preferably For 0-0.5%.

ZnO is added in right amount can improve the chemical stability of glass in glass, while the height of glass can also be reduced Warm viscosity and Tg temperature.But, if ZnO additions are excessive, the devitrification resistance of glass be able to can decline, together When high temperature viscosity it is smaller, bring difficulty to shaping.In this glass system, if ZnO content is less than 10%, Then Tg temperature does not reach design requirement；If its content is higher than 20%, the devitrification resistance of glass be able to can decline, high Warm viscosity does not reach design requirement.Therefore, ZnO content is defined to be more than 10% but less than or equal to 20%, Preferably 11-16%, more preferably 11-14.5%.

The present invention in order to obtain relatively low Tg temperature and stability is good, be easy to fusing glass, inventor passes through big Measure experimental study to find, as ZnO/ (B₂O₃+SiO₂) scope be 0.25-0.65, preferably ZnO/ (B₂O₃+SiO₂) Scope is 0.30-0.55, further preferred ZnO/ (B₂O₃+SiO₂) scope be 0.30-0.50 when, glass Stability and Tg temperature obtain quality preferably product up to optimum balance.

ZrO₂Belong to high refraction oxide, the refractive index of glass can be significantly improved, while the chemistry for improving glass is steady It is qualitative；In the present invention, ZrO₂Glass dispersed effect extremely is also improved, the exception of glass is dispersed favourable Second order spectrum is eliminated in optical design, its content is too low, then foregoing advantages are not obvious, but addition is excessive The crystallization risk of glass can be significantly improved.Therefore, its content is defined to 6.5-15%, preferably 6.5-10%, More preferably 6.5-8.5%.

As optical glass, its optical transmittance is considerable performance indications, as (ZrO₂+Y₂O₃)/ (Nb₂O₅+Gd₂O₃) scope control in 0.30-1.50, be preferably controlled in 0.48-1.10, more preferably control In 0.50-1.00, still more preferably control in 0.50-0.70, currently preferred refractive index can be achieved While with Abbe number scope, it also can effectively suppress glass coloration, and improve the heat endurance of glass and resistance to mistake Permeability energy.

It is a small amount of to introduce Al₂O₃The stability and chemical stability for forming glass can be improved, but its content is more than 10% When, display glass melting is deteriorated, the tendency of devitrification resistance reduction, therefore Al of the present invention₂O₃Content be 0-10%, preferably 0-5%, more preferably 0-1%, are not introduced further preferably.

Li₂O is added in glass ingredient, can effectively reduce the Tg temperature of glass.But low softening point optics Glass is usually using platinum or platinum alloy vessel melting, during high melt, the Li in glass ingredient⁺Easily Corrode platinum or platinum alloy vessel, cause to produce more platiniferous foreign matter in finished glass, cause the quality of glass Decline.On the other hand, when such glass is for during precise compression molding, glass elements surface modes are easily produced The risk of paste, reason is that the Li in the releasing agent that carbon elements are typically coated with mould, glass ingredient is easy Reacted with the carbon in releasing agent, coarse opaque film layer is produced on glass original paper surface.Therefore, Its content is defined to 0-10%, more preferably preferably 0-5%, 0-1%.

Na₂O and K₂O is any condition effective to reduction Tg, if its composition is excessive, is easily caused mistake Saturating temperature rises and is difficult to vitrifying, therefore its content is defined to 0-10%, more preferably 0-5% respectively, enters One step is preferably 0-1%.

The present inventor had found by lot of experiments, Ta₂O₅+Nb₂O₅Total content and ZnO+Li₂O's is total There is considerable influence in the chemical stability and Tg temperature to this glass of content, as (Ta₂O₅+Nb₂O₅)/ (ZnO+Li₂When O) more than 0.45, the Tg temperature of glass is significantly raised, and is unfavorable for accurate die pressing, when (Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) be less than 0.10 when, the chemical stability of this glass can significantly increase and Effectively reduce glass density.In consideration of it, in glass of the present invention, (Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) limit Surely it is less than 0.45, preferably (Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) it is less than 0.10, more preferably (Ta₂O₅+Nb₂O₅) /(ZnO+Li₂O) it is less than 0.07, further preferred (Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) it is less than 0.01.

RO (RO is the one or more in MgO, CaO, SrO or BaO) can improve the meltbility of glass, Glass photosensitiveness is adjusted, but when its content is more than 10%, the devitrification resistance reduction of glass, therefore the present invention is preferably RO contents are 0-10%, and more preferably scope is 0-5%, more preferably 0-1%.

Bi₂O₃Glass refraction can be improved, but excessively containing the short wavelength side for then showing visible region sometimes Decrease in transmission, glass is coloured, therefore the present invention preferably Bi₂O₃Content is 0-10%, more Preferably 0-5%, more preferably 0-1%, are not introduced still more preferably.

GeO₂Also the stability and devitrification resistance to form glass can be effectively improved, but due to GeO₂It is very expensive Component, therefore preferably GeO₂Content is respectively 0-10%, more preferably 0-5%, more preferably 0-1%, Do not introduce still more preferably.

By adding Sb on a small quantity₂O₃、CeO₂Component can improve the clarifying effect of glass, but work as Sb₂O₃Content surpasses When 1%, glass has devitrification resistance property reduction, the risk of dispersion increase, simultaneously because its strong oxidation promotees The deterioration of mould, therefore the present invention preferably Sb are entered₂O₃Addition be 0-1%, more preferably 0-0.5%, Further preferably it is added without.CeO₂Effect and addition ratio and Sb₂O is consistent, and its content is preferably 0-1%, More preferably 0-0.5%, further preferably without.

F is that have the composition of larger effect for the temperature coefficient for improving light refractiveness, reducing relative index of refraction, But generation environment load problem of being volatilized in its production process, while can be because of it in operations for forming temperature province Heterogeneity part is formed from glass surface volatilization, so as to be difficult to be suitable as optical element, is in the present invention Make glass quality excellent, optical constant uniformity is good, therefore does not introduce F components.

Below, the characteristic to the optical glass of the present invention is illustrated.

[optical constant of optical glass]

The optical glass of the present invention is high-refractivity and low-dispersion glass, and it is saturating that high-refractivity and low-dispersion glass is made The lens that mirror is made with high index of refraction high-dispersion glass more are combined, for chromatic aberration correction.The optics of the present invention Glass is from the point of view of the optical characteristics suitable for its purposes is assigned, and glass refraction nd scope is 1.76-1.80, scope preferably is 1.76-1.79, and preferred scope is 1.76-1.78, further excellent The scope of choosing is 1.77-1.78；The Abbe number ν of glass of the present invention_dScope be 47-51, preferred scope is 48-50, more preferably scope are 49-50.

[coloring of optical glass]

The shortwave transmitted spectrum characteristic degree of staining (λ of glass of the present invention₈₀/λ₅) represent.λ₈₀Refer to that glass is saturating Penetrate than reaching corresponding wavelength, λ when 80%₅Refer to that glass transmittance reaches corresponding wavelength when 5%.Wherein, λ₈₀Measure be use the thickness with two parallel to each other and optical polish relative planes for 10 ± 0.1nm glass, determines the spectral transmission in the wavelength domain from 280nm to 700nm and shows transmissivity 80% wavelength.So-called spectral transmission or transmissivity are in the vertically incident intensity I of the above-mentioned surface to glass_in Light, project intensity I through glass and from plane_outLight in the case of pass through I_out/I_inThe amount of expression, And it also contains the transmissivity of the surface reflection loss on the above-mentioned surface of glass.The refractive index of glass is higher, Surface reflection loss is bigger.Therefore, in glass of high refractive index, λ₈₀Value it is small mean glass itself Color is few.

The optical glass λ of the present invention₈₀Less than or equal to 400nm, preferably λ₈₀Scope be less than or equal to 395nm, more preferably λ₈₀Scope be less than or equal to 390nm, further preferred λ₈₀Scope be less than Or equal to 385nm, λ still further preferably₈₀Scope be less than or equal to 380nm.λ₅It is less than or equal to 300nm, preferably λ₅Scope be less than or equal to 290nm, more preferably λ₅Scope be less than or equal to 285nm, further preferred λ₅Scope be less than or equal to 280nm.

[density of optical glass]

The density of optical glass is the quality of unit volume when temperature is 20 DEG C, and unit is with g/cm³Represent.

The density of glass of the present invention is in 5.00g/cm³Hereinafter, preferably 4.80g/cm³Hereinafter, more preferably 4.70g/cm³Hereinafter, more preferably 4.60g/cm³Below.

[transition temperature of optical glass]

Optical glass gradually can become mouldable state in a certain temperature range by solid-state.Transition temperature refers to that glass is tried Sample is from room temperature to temperature of hanging down of speeding, its low-temperature region and the intersecting intersection point of high-temperature area straight line portion extended line Corresponding temperature.

The transition temperature Tg of glass of the present invention is below 625 DEG C, preferably less than 620 DEG C, more preferably 615 DEG C with Under, more preferably less than 610 DEG C.

IIth, optical precast product and optical element

Below, the optical precast product and optical element of the present invention is described.

The optical precast product of the present invention is formed with optical element by the optical glass of the invention described above.The present invention Optical precast product there is high-refractivity and low-dispersion characteristic；The optical element of the present invention has the low color of high index of refraction Characteristic is dissipated, the optical elements such as the costly various lens of optics, prism can be provided with low cost.

As the example of lens, it is sphere or aspherical recessed meniscus shaped lens, male bend month that can enumerate lens face The various lens such as shape lens, biconvex lens, biconcave lens, planoconvex spotlight, plano-concave lens.

This lens are adapted to by the lens combination being made with high index of refraction high-dispersion glass, recoverable aberration It is used as the lens of chromatic aberration correction.In addition, the densification for optics system is also effective lens.

In addition, for prism, because refractive index is high, therefore by combining in camera optical system, By bending light path, towards required direction, you can realize compact, wide-angle optics system.

[optical glass embodiment]

The present invention is explained using following examples, but the present invention should not be limited to these embodiments.

The melting and forming method for producing optical glass can be using well known to a person skilled in the art technology.Will Frit (carbonate, nitrate, sulfate, hydroxide, oxide, boric acid etc.) is according to glass The proportioning of oxide weigh with merge it is well mixed after, (such as platinum crucible), Ran Hou in input smelting apparatus 1150~1400 DEG C are taken after appropriate stirring, clarification, homogenizing, are cooled to less than 1250 DEG C, are poured into a mould or are leaked Note is in mould, the post-processing such as last annealed, processing, or direct by precise compression molding technology It is compressing.

The characteristic of each glass of the present invention is determined by method as shown below, and measurement result is represented in table In 1~table 9.

(1) refractive index nd and Abbe number ν d

Refractive index is tested with abbe number according to method as defined in GB/T7962.1-2010.

(2) glass coloration degree (λ₈₀、λ₅)

Using the glass sample that the thickness with two optical polish planes relative to each other is 10 ± 0.1mm, Spectral transmission is determined, is calculated according to its result.

(3) glass transformation temperature (Tg)

Method is measured as defined in GB/T7962.16-2010.

(4) proportion (ρ)

Method is measured as defined in GB/T7962.20-2010.

Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Table 7

Table 8

Table 9

[optical precast product embodiment]

Optical glass obtained by embodiment 1 in table 1 is cut into predefined size, then on the surface equably Coated release agent, is then heated, softens, be press-formed, and makes recessed meniscus shaped lens, male bend The various lens such as moon-shaped lens, biconvex lens, biconcave lens, planoconvex spotlight, plano-concave lens, prism it is pre- Product.

[optical element embodiment]

By these prefabricated components annealing obtained by above-mentioned optical precast product embodiment, in the change of reduction inside glass It is finely adjusted while shape so that the optical characteristics such as refractive index reaches desirable value.

Then, each prefabricated component is ground, ground, make recessed meniscus shaped lens, male bend moon-shaped lens, The various lens such as biconvex lens, biconcave lens, planoconvex spotlight, plano-concave lens, prism.Gained optical element Surface on can also be coated with antireflection film.

The present invention is low cost and the optical glass of the excellent high refractive low dispersive of transmitance, and refractive index is 1.76-1.80, Abbe number is 47-51, and glass formation optical element, disclosure satisfy that modern new The need for type photovoltaic.

Claims (12)

1. optical glass, it is characterised in that its percentage by weight composition includes：SiO₂：0-3%；B₂O₃：25-40%； La₂O₃：20-40%；Gd₂O₃：12-25%；ZrO₂：6.5-15%；ZnO：More than 10% but less than or equal to 20%； Ta₂O₅：0-5%；Nb₂O₅：0-5%；Li₂O：0-10%；(Ta₂O₅+Nb₂O₅)/(ZnO+Li₂O) it is less than 0.45； Y₂O₃：0-10%；The transition temperature Tg of glass is below 625 DEG C.

2. optical glass as claimed in claim 1, it is characterised in that also contain：GeO₂：0-10%；Bi₂O₃： 0-10%；Al₂O₃：0-10%；Na₂O：0-10%；K₂O：0-10%；CeO₂：0-1%；Sb₂O₃：0-1%；RO： 0-10%, wherein, RO is the one or more in MgO, CaO, SrO or BaO.

3. optical glass as claimed in claim 2, it is characterised in that wherein, Al₂O₃：0-5% and/or Na₂O： 0-5% and/or K₂O：0-5% and/or GeO₂：0-5% and/or Bi₂O₃：0-5% and/or CeO₂：0-0.5% and/ Or Sb₂O₃：0-0.5% and/or RO：0-5%.

4. optical glass as claimed in claim 2, it is characterised in that wherein, Al₂O₃：0-1% and/or Na₂O： 0-1% and/or K₂O：0-1% and/or GeO₂：0-1% and/or Bi₂O₃：0-1% and/or RO：0-1%.

5. optical glass as claimed in claim 1 or 2, it is characterised in that wherein, (ZrO₂+Y₂O₃)/ (Nb₂O₅+Gd₂O₃) it is 0.30-1.50；La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) it is 0.38-0.75；ZnO/ (B₂O₃+SiO₂) it is 0.25-0.65.

6. optical glass as claimed in claim 1 or 2, it is characterised in that wherein, B₂O₃：28.5-35% And/or La₂O₃：25-35% and/or Gd₂O₃：14-22% and/or ZrO₂：6.5-10% and/or ZnO：11-16% And/or SiO₂：0-1% and/or Ta₂O₅：0-1% and/or Nb₂O₅：0-1% and/or Y₂O₃：0-7% and/or Li₂O： 0-5%.

7. optical glass as claimed in claim 1 or 2, it is characterised in that wherein, B₂O₃：29-32% And/or La₂O₃：27-32% and/or Gd₂O₃：15-20% and/or ZrO₂：6.5-8.5% and/or ZnO：11-14.5% And/or SiO₂：0-0.5% and/or Ta₂O₅：0-0.5% and/or Nb₂O₅：0-0.5% and/or Y₂O₃：0.1-5% And/or Li₂O：0-1%.

8. optical glass as claimed in claim 1 or 2, it is characterised in that wherein, (Ta₂O₅+Nb₂O₅) /(ZnO+Li₂O) it is less than 0.10；And/or La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) it is 0.45-0.70；And/or ZnO/(B₂O₃+SiO₂) it is 0.30-0.55；And/or (ZrO₂+Y₂O₃)/(Nb₂O₅+Gd₂O₃) it is 0.48-1.10.

9. optical glass as claimed in claim 1 or 2, it is characterised in that wherein, (Ta₂O₅+Nb₂O₅) /(ZnO+Li₂O) it is less than 0.07；And/or La₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) it is 0.55-0.65；And/or ZnO/(B₂O₃+SiO₂) it is 0.30-0.50；And/or (ZrO₂+Y₂O₃)/(Nb₂O₅+Gd₂O₃) it is 0.50-1.0.

10. optical glass as claimed in claim 1 or 2, it is characterised in that glass refraction is 1.76-1.80；The Abbe number of glass is 47-51；Density is in 5.00g/cm³Below.

11. gas preform, is made of the optical glass described in claim 1-10.

12. optical element, is made of the optical glass described in claim 1-10.