Optical glass, optical elements, optical systems, interchangeable lenses and optical devices

Abstract

SOLUTION: The provide an optical glass including, by cation%, P5+ component: 30-45%, Al3+ component: 10-20%, and Ba2+ component: 20-40% and, by anion%, O2-component: 75-95% and F-component: 5-25%.EFFECT: An optical glass according to the present invention boasts a high refractive index, low dispersion, and high anomalous dispersion, offering superior qualities even without the addition of costly components, thereby allowing for low-cost production. It not only has excellent optical constants but also reduces striae within the glass and offers strong resistance to devitrification.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to optical glass, an optical element, an optical system, an interchangeable lens, and an optical device. [Background technology]

[0002] In the course of development of digital cameras, high refractive index, low dispersion optical glass, for example, as disclosed in Patent Document 1, is used in the optical systems used in digital cameras. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-286670 A Summary of the Invention

[0004] The first aspect of the present invention is a compound having a molar percentage of cations of P 5+ Content: 30% to 45%, Al 3+ Content rate: 10% or more and 20% or less, Ba 2+ Content: 20% or more and 40% or less, Li + , Ti 4+ At least one of the following is included: Mole % of anions: O 2- Content rate: 75% or more and 95% or less, F - Content: 5% or more and 25% or less, and Abbe number (ν d ) is 40 or more and 65 or less. Another aspect of the invention is a compound having, in mole percent of cations, P 5+ Content: 30% to 45%, Al 3+ Content rate: 10% or more and 20% or less, Ba 2+ Content: 20% to 40%; Ti 4+ 、Zr 4+ , Nb 5+ , Ta 5+ 、W 6+ Total content (ΣTMn+ ) is more than 0 and 10% or less, and the molar percentage of the anion is O 2- Content rate: 75% or more and 95% or less, F - The content is 5% or more and 25% or less, and the Abbe number (νd) is 40 or more and 65 or less, making it an optical glass.

[0005] The present invention others The embodiment (2) is an optical element using the optical glass described above.

[0006] The present invention others The aspect is an optical system including the optical element described above.

[0007] The present invention others The third aspect is an interchangeable lens including the optical system described above.

[0008] The present invention others The second aspect is an optical device including the optical system described above. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an imaging device equipped with an optical element using the optical glass according to this embodiment. [Diagram 2] FIG. 2 is a front view of another example of an imaging device equipped with an optical element using the optical glass according to this embodiment. [Diagram 3] FIG. 3 is a rear view of the imaging device of FIG. [Figure 4] FIG. 4 is a block diagram showing an example of the configuration of a multiphoton microscope equipped with an optical element using the optical glass according to this embodiment. [Diagram 5] FIG. 5 is a graph plotting the Abbe number (νd) and the partial dispersion ratio (Pg,F) of each of the examples and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described. The present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content.

[0011] The optical glass according to this embodiment contains, in cationic %, P 5+ Ingredients: 30~45%, Al 3+ Ingredients: 10-20%, Ba 2+ Ingredients: 20-40%, anion%, O 2- Ingredients: 75-95%, F - Ingredients: 5~25%, which is optical glass.

[0012] In this specification, unless otherwise specified, the content ratio of each component is expressed as cationic % or anionic % on a molar ratio basis.

[0013] The optical glass according to this embodiment has a high refractive index, low dispersion, and high anomalous dispersion. The optical glass according to this embodiment can be produced at low cost because it can be imparted with excellent properties without containing expensive components. The optical glass according to this embodiment not only has excellent optical constants, but also can suppress the occurrence of striae inside the glass and has high resistance to devitrification.

[0014] Furthermore, as one of the preferred aspects of this embodiment, it is possible to obtain an optical glass having high positive anomalous dispersion while maintaining a high refractive index. For example, conventional optical glasses having positive anomalous dispersion cannot increase the refractive index, and have a problem that it is difficult to achieve both the power (refractive power) and the ability to correct chromatic aberration when used in a convex lens or the like. The optical glass according to this embodiment can solve such problems, can be applied to a wide range of uses, and can fully meet the needs at a practical level.

[0015] Generally, as the Abbe number of optical glass increases (low dispersion), the refractive index decreases. In view of the above-mentioned circumstances, however, the "high refractive index" in this embodiment also includes a relatively high refractive index compared to general optical glass having a comparable Abbe number, and does not necessarily mean only that the absolute value of the refractive index is large.

[0016] (cationic component)

[0017] P 5+ is a component that forms the glass skeleton and enhances resistance to devitrification. 5+ If the content of P is too low, the devitrification resistance tends to decrease. 5+ If the content of P is too high, the refractive index tends to decrease. 5+ The content is 30 to 45%. The upper limit is preferably 41%, more preferably 40%. The lower limit is preferably 37%, more preferably 39%.

[0018] In addition, B 3+ is also generally used as a component for forming the glass skeleton, but in the optical glass according to this embodiment, B 3+ F - This may result in a deterioration in the quality of the optical glass. 3+ It is preferable to reduce the content of, and more preferably to contain substantially no.

[0019] In this specification, the term "substantially not contained" means that the component is not contained as a constituent component that affects the properties of the glass composition at a concentration exceeding the concentration that is inevitably contained as an impurity. For example, a content of about 100 ppm is considered to be substantially not contained.

[0020] Al 3+ Al is a component that improves resistance to devitrification and reduces dispersion. 3+If the content is too low, the low dispersion tends to be lost, 3+ If the content is too high, the ΔP g,F From this perspective, the Al value tends to decrease. 3+ The content is 10 to 20%. The upper limit is preferably 18%, more preferably 16%. The lower limit is preferably 12%, more preferably 14%.

[0021] Ba 2+ is ΔP g,F It is a component that increases the refractive index while maintaining the original value. 2+ If the content is too low, the refractive index tends to decrease, 2+ If the content of Ba is too high, the devitrification resistance tends to decrease. 2+ The content is 20 to 40%. The upper limit is preferably 36%, more preferably 32%. The lower limit is preferably 24%, more preferably 28%.

[0022] The optical glass of this embodiment may further contain the following components as necessary.

[0023] Li + is ΔP g,F It is an ingredient that increases the value and refractive index of the glass and also improves the melting property of the glass. + If the content of Li is too high, the devitrification resistance tends to decrease. + The content is preferably 0 to 6%. The upper limit is more preferably 4%, and further preferably 3%. The lower limit is more preferably 1%, and further preferably 2%.

[0024] Na + and K + Although Na can be used as a component that can enhance the meltability of the glass, it may significantly lower the refractive index. + , K +Of course, when it is desired to particularly improve the meltability of the glass, these may be contained.

[0025] Mg 2+ is ΔP g,F It is a component that increases the refractive index while maintaining the original value. 2+ If the content of Mg is too high, the devitrification resistance tends to decrease. 2+ The content is preferably 0 to 15%. The upper limit is more preferably 12%, and further preferably 8%. The lower limit is more preferably 3%, and further preferably 4%.

[0026] Ca 2+ is ΔP g,F It is a component that increases the refractive index while maintaining the value. 2+ If the content of Ca is too high, the devitrification resistance tends to decrease. 2+ The content is preferably 0 to 20%. The upper limit is more preferably 10%, and further preferably 6%. The lower limit is more preferably 2%, and further preferably 3%.

[0027] Sr 2+ is ΔP g,F However, Sr 2+ If the content of Sr is too high, the devitrification resistance tends to decrease. 2+ The content is preferably 0 to 20%. The upper limit is more preferably 10%, and further preferably 6%. The lower limit is more preferably 2%, and further preferably 3%.

[0028] Zinc 2+ is a component that increases the refractive index and also improves the melting property of glass. 2+ If the content of Zn is too high, the low dispersion tends to be impaired. 2+The content is preferably 0 to 15%. The upper limit is more preferably 8%, and further preferably 4%. The lower limit is more preferably 1%, and further preferably 2%.

[0029] Y 3+ is a component that increases the refractive index. 3+ If the content of Y is too high, the devitrification resistance tends to decrease. 3+ The content is preferably 0 to 6%. The upper limit is more preferably 4%, and further preferably 2%. The lower limit is more preferably 0.5%, and further preferably 1%.

[0030] La 3+ is a component that increases the refractive index. 3+ If the content of La is too high, the devitrification resistance tends to decrease. 3+ The content is preferably 0 to 6%. The upper limit is more preferably 4%, and further preferably 2%. The lower limit is more preferably 0.5%, and further preferably 1%.

[0031] Gd 3+ is a component that increases the refractive index. 3+ If the content of Gd is too high, the devitrification resistance tends to decrease. 3+ The content is preferably 0 to 6%. The upper limit is more preferably 4%, and further preferably 2%. The lower limit is more preferably 0.5%, and further preferably 1%.

[0032] Ti 4+ is ΔP g,F It is a component that increases the refractive index while maintaining the original value. 4+ If the Ti content is too high, the low dispersion tends to be impaired. 4+The content is preferably 0 to 6%. The upper limit is more preferably 4.5%, and further preferably 3%. The lower limit is more preferably 0.5%, and further preferably 1%.

[0033] Zr 4+ is ΔP g,F It is a component that increases the refractive index while maintaining the value. 4+ If the content of Zr is too high, the low dispersion tends to be impaired. 4+ The content is preferably 0 to 3%. The upper limit is more preferably 2%, and further preferably 1%. The lower limit is more preferably 0.5%.

[0034] Nb 5+ is ΔP g,F It is a component that increases the refractive index while maintaining the original value. 5+ If the content of Nb is too high, the low dispersion tends to be impaired. 5+ The content is preferably 0 to 8%. The upper limit is more preferably 6%, and further preferably 4%. The lower limit is more preferably 1%, and further preferably 2%.

[0035] Ta 5+ is ΔP g,F It is a component that increases the refractive index while maintaining the Ta value. 5+ If the content of Ta is too high, the low dispersion tends to be impaired. 5+ The content is preferably 0 to 4%. The upper limit is more preferably 3%, and further preferably 2%. The lower limit is more preferably 0.5%, and further preferably 1%.

[0036] However, Ta 5+ Since Ta is an expensive raw material, it is desirable to reduce its content. Therefore, when cost reduction is given priority, the optical glass according to this embodiment contains Ta 5+In this way, the optical glass according to this embodiment does not substantially contain Ta, which is an expensive raw material. 5+ Since excellent physical properties can be exhibited without containing any of the above, it is also advantageous in terms of cost.

[0037] In addition, the optical glass according to this embodiment is made of Ge from the viewpoint of cost. 4+ , Te 4+ It is preferable that the composition is substantially free of

[0038] W 6+ is ΔP g,F It is a component that increases the refractive index while maintaining the value. 6+ If the content of W is too high, the low dispersion tends to be impaired. 6+ The content is preferably 0 to 6%. The upper limit is more preferably 4%, and further preferably 2%. The lower limit is more preferably 0.5%, and further preferably 1%.

[0039] Sb 3+ is a component that imparts a defoaming effect. 3+ The content is preferably 0 to 1%. The upper limit is more preferably 0.5%, and further preferably 0.2%. The lower limit is more preferably 0.1%.

[0040] From the viewpoint of further improving the physical properties of the optical glass according to this embodiment, Li + Ingredients, Mg 2+ Ingredients, Ca 2+ Ingredients, Sr. 2+ Ingredients, Zn 2+ Component, Y 3+ Ingredients, La 3+ Component, Gd 3+ Ingredients: Ti 4+ Composition: Zr 4+ Component, Nb 5+ Ingredients, Ta 5+ Ingredients, and W 6+ It is preferable that the composition contains one or more components selected from the group consisting of:

[0041] As a suitable combination of the above-mentioned optional components, Li + Ingredients: 0~6%, Mg 2+ Ingredients: 0~15%, Ca 2+ Ingredients: 0~20%, Sr 2+ Ingredients: 0~20%, Zn 2+ Ingredients: 0-15%, Y 3+ Ingredients: 0-6%, La 3+ Ingredients: 0-6%, Gd 3+ Ingredients: 0~6%, Ti 4+ Composition: 0-6%, Zr 4+ Ingredients: 0-3%, Nb 5+ Ingredients: 0-8%, Ta 5+ Ingredients: 0-4%, W 6+ Component: 0 to 6%. By using such components in combination, the physical properties of the optical glass can be further improved.

[0042] Furthermore, in the optical glass according to this embodiment, it is preferable that the following conditions are further satisfied.

[0043] In order to improve the resistance to devitrification and to obtain a high refractive index, P 5+ Ingredients+Al 3+ The component is preferably 40 to 65%. The upper limit is more preferably 58%, and further preferably 55%. The lower limit is more preferably 45%, and further preferably 53%.

[0044] In order to improve the resistance to devitrification and to obtain a high refractive index, Mg 2+ Ingredients +Ca 2+ Ingredients + Sr 2+ Ingredient +Ba 2+ Ingredients + Zn 2+ Ingredients (ΣAE 2+ ) is preferably 35 to 50%. The upper limit is more preferably 44%, and further preferably 41%. The lower limit is more preferably 36%, and further preferably 39%.

[0045] From the viewpoint of improving the resistance to devitrification and achieving a high refractive index, Y 3+ Ingredients + La 3+ Ingredients + Gd 3+Ingredients (ΣRE 3+ ) is preferably 0 to 6%. The upper limit is more preferably 5%, and further preferably 3%. The lower limit is more preferably 0.5%, and further preferably 1%.

[0046] Improved resistance to devitrification, high refractive index and high ΔP g,F From the viewpoint of value, Ti 4+ Ingredients + Zr 4+ Ingredients + Nb 5+ Ingredients + Ta 5+ Ingredients + W 6+ component(ΣTM n+ ) is preferably more than 0 and 10% or less. The upper limit is more preferably 5% or less, and further preferably 4% or less. The lower limit is more preferably 0.5% or more, and further preferably 1% or more.

[0047] Improved resistance to devitrification, high Abbe number and high ΔP g,F From the viewpoint of value, Al 3+ P for components 5+ Proportion of components (P 5+ / Al 3+ ) is preferably 1.5 to 4.5. The upper limit is more preferably 4, and further preferably 3. The lower limit is more preferably 2, and further preferably 2.5.

[0048] Improved resistance to devitrification, high refractive index and high ΔP g,F From the viewpoint of value, Mg 2+ Ingredients +Ca 2+ Ingredients + Sr 2+ For the components, Ba 2+ Ingredients + Zn 2+ The proportion of components (Ba 2+ +Zn 2+ ) / (Mg 2+ +Ca 2+ +Sr 2+ )) is preferably 0.5 to 10. The upper limit is more preferably 5, and further preferably 3. The lower limit is more preferably 1, and further preferably 2.

[0049] High refractive index and high ΔP while maintaining resistance to devitrification g,F From the perspective of obtaining the value, P 5+ Ingredients+Al 3+ Li for the components + Ingredients + Mg 2+ Ingredients +Ca 2+ Ingredients + Sr 2+ Ingredient +Ba 2+ Ingredients + Zn 2+ Ingredient + Y 3+ Ingredients + La 3+ Ingredients + Gd 3+ Ingredients+Ti 4+ Ingredients + Zr 4+ Ingredients + Nb 5+ Ingredients + Ta 5+ Ingredients + W 6+ component + Percentage of (Li + +ΣAE 2+ +ΣRE 3+ +ΣTM n+ ) / (P 5+ +Al 3+ )) is preferably 0.7 to 1.3. The upper limit is more preferably 1.1, and further preferably 0.9. The lower limit is more preferably 0.75, and further preferably 0.8.

[0050] High refractive index and high ΔP g,F From the viewpoint of the atomic percent (at%) value, - Ti for the components 4+ Ingredients + Zr 4+ Ingredients + Nb 5+ Ingredients + Ta 5+ Ingredients + W 6+ component(ΣTM n+ ) ratio ((ΣTM n+ ) / F - ) is preferably 0.05 to 0.35. The upper limit is more preferably 0.2, and further preferably 0.12. The lower limit is more preferably 0.06, and further preferably 0.08.

[0051] (anion component)

[0052] O -The content is 75 to 95%. The upper limit is preferably 90%, and more preferably 86%. The lower limit is preferably 82%, and more preferably 84%.

[0053] F - is ΔP g,F It is a component that increases the value and Abbe number. - If the content is too low, ΔP g,F The value tends to decrease and the low dispersion tends to be lost. - If the content of F is too high, the refractive index tends to decrease. - The content is 5 to 25%. The upper limit is preferably 18%, more preferably 16%. The lower limit is preferably 10%, more preferably 14%.

[0054] The optical glass according to this embodiment may contain an anion component other than the above-mentioned components. When used as a fluoride-based glass, however, O - and F - The composition may contain only

[0055] However, the O - and F - When only O is contained, - and F - This means that an anion component other than O is not contained as a component that affects the properties of the glass composition, exceeding the concentration that is inevitably contained as an impurity. For example, O - and F - If an anionic component other than the above is present at a content of about 100 ppm, it is considered that such anionic component is substantially not contained.

[0056] Furthermore, for the purpose of clarifying, coloring, decoloring, fine adjustment of optical constants, etc., appropriate amounts of known clarifiers, colorants, defoamers, oxides, and other components may be added to the glass composition as needed. In addition to the above-mentioned components, other components may also be added within the range in which the effects of the optical glass of this embodiment can be obtained.

[0057] Next, the physical properties of the optical glass of this embodiment will be described.

[0058] From the viewpoint of making the lens thinner, the optical glass according to this embodiment has a high refractive index (refractive index (n d However, in general, the higher the refractive index, the lower the Abbe number tends to be. d ) is preferably in the range of 1.60 to 1.70. The refractive index, Abbe number and ΔP g,F Since the refractive index and the refractive index tend to be in a trade-off relationship, the upper limit of the refractive index is more preferably 1.67, and even more preferably 1.64, and the lower limit is more preferably 1.61, and even more preferably 1.62.

[0059] From the viewpoint of lens aberration correction, the optical glass according to this embodiment has low dispersion (Abbe number (ν d However, in general, the refractive index tends to decrease as the Abbe number increases. Therefore, it is desirable to have a large Abbe number (ν d ) is preferably in the range of 40 to 65. The refractive index, Abbe number and ΔP g,F Since the values ​​tend to be in a trade-off relationship, the upper limit is more preferably 63, and further preferably 61. The lower limit is more preferably 50, and further preferably 58.

[0060] The optical glass according to this embodiment has a partial dispersion ratio (P g,F ) is preferably 0.550 to 0.570. The upper limit is more preferably 0.562, and even more preferably 0.558. The lower limit is more preferably 0.552, and even more preferably 0.554.

[0061] The optical glass according to this embodiment has a ΔP g,F The refractive index, Abbe number and ΔP value are preferably in the range of 0.005 to 0.015. g,FSince the values ​​of ΔP tend to be in a trade-off relationship, the upper limit is more preferably 0.013, and even more preferably 0.011. The lower limit is more preferably 0.007, and even more preferably 0.009. g,F The value is an index of anomalous dispersion.

[0062] The optical glass according to this embodiment has a specific gravity (S g ) is preferably 3.90 to 4.20. The upper limit is more preferably 4.15, and even more preferably 4.10. The lower limit is more preferably 3.95, and even more preferably 4.00.

[0063] The optical glass according to this embodiment has a glass transition temperature (T g ) is preferably 650° C. or less. The upper limit is more preferably 620° C., and further preferably 600° C. By setting the glass transition temperature within this range, good moldability can be achieved.

[0064] The manufacturing method of the optical glass according to this embodiment is not particularly limited, and a known method can be adopted. In addition, the manufacturing conditions can be appropriately selected from suitable conditions. One suitable example includes a method including a process of selecting one type of glass raw material selected from oxides, hydroxides, phosphoric acid compounds (phosphates, orthophosphoric acid, etc.), carbonates, sulfates, fluorides, nitrates, etc. corresponding to the above-mentioned respective raw materials, mixing them, melting them at a temperature of 1100 to 1400°C, stirring and homogenizing them, and then cooling and molding them.

[0065] More specifically, raw materials such as oxides, hydroxides, phosphate compounds (phosphates, orthophosphates, etc.), carbonates, sulfates, fluorides, and nitrates are mixed to obtain a target composition, melted at preferably 1100 to 1400° C., more preferably 1100 to 1300° C., and even more preferably 1100 to 1250° C., homogenized by stirring, bubble-removing, and then molded in a mold. The optical glass thus obtained can be processed into a desired shape by reheat pressing or the like as necessary, and polished to obtain a desired optical glass or optical element.

[0066] As described above, the optical glass according to this embodiment has a high refractive index, low dispersion, and high anomalous dispersion, and is therefore suitable as an optical element such as a lens for an optical device such as a camera or a microscope. Such optical elements include mirrors, lenses, prisms, filters, and the like. Examples of optical systems including these optical elements include objective lenses, condenser lenses, imaging lenses, and interchangeable lenses, and more preferably can be used as interchangeable lenses for cameras. These optical systems can be used in imaging devices such as interchangeable lens cameras and non-interchangeable lens cameras, and microscopes such as multiphoton microscopes. The optical devices are not limited to the imaging devices and microscopes described above, but also include video cameras, teleconverters, telescopes, binoculars, monoculars, laser range finders, projectors, and the like. When the optical glass according to this embodiment is used for such applications, it is possible to reduce chromatic aberration and obtain power as a convex lens. An example of these is described below.

[0067] <Imaging device> FIG. 1 is a perspective view of an imaging device equipped with an optical element using the optical glass according to this embodiment.

[0068] The imaging device 1 is a so-called digital single-lens reflex camera (interchangeable lens camera), and the photographing lens 103 (optical system) is equipped with an optical element whose base material is the optical glass according to this embodiment. A lens barrel 102 is detachably attached to a lens mount (not shown) of a camera body 101. Light passing through a lens 103 of the lens barrel 102 forms an image on a sensor chip (solid-state imaging element) 104 of a multi-chip module 106 arranged on the rear side of the camera body 101. The sensor chip 104 is a bare chip such as a so-called CMOS image sensor, and the multi-chip module 106 is, for example, a COG (Chip On Glass) type module in which the sensor chip 104 is bare-chip mounted on a glass substrate 105.

[0069] FIG. 2 is a front view of another example of an imaging device equipped with an optical element using the optical glass according to this embodiment, and FIG. 3 is a rear view of the imaging device of FIG.

[0070] This imaging device CAM is a so-called digital still camera (lens non-interchangeable camera), and the photographing lens WL (optical system) is equipped with an optical element whose base material is the optical glass according to this embodiment.

[0071] When a power button (not shown) of the imaging device CAM is pressed, a shutter (not shown) of the taking lens WL is opened, and light from a subject (object) is collected by the taking lens WL and imaged on an imaging element arranged on an image plane. The subject image formed on the imaging element is displayed on a liquid crystal monitor LM arranged behind the imaging device CAM. After the photographer decides on the composition of the subject image while looking at the liquid crystal monitor LM, he or she presses down the release button B1 to capture the subject image with the imaging element, which is then recorded and saved in memory (not shown).

[0072] The image pickup device CAM is provided with an auxiliary light emitting section EF that emits auxiliary light when the subject is dark, a function button B2 used for setting various conditions of the image pickup device CAM, and the like.

[0073] The optical systems used in digital cameras and other devices require higher resolution, lighter weight, and smaller size. To achieve these goals, it is effective to use glass with a high refractive index. In particular, glass with a high refractive index and a low specific gravity (S g ) and has high press moldability, there is a high demand. From this viewpoint, the optical glass according to this embodiment is suitable as a component of such optical equipment. Note that optical equipment to which this embodiment can be applied is not limited to the above-mentioned imaging device, but also includes, for example, a projector. The optical element is also not limited to a lens, but also includes, for example, a prism.

[0074] <Multiphoton microscope> FIG. 4 is a block diagram showing an example of the configuration of a multiphoton microscope 2 equipped with an optical element using the optical glass according to this embodiment.

[0075] The multiphoton microscope 2 includes an objective lens 206, a condenser lens 208, and an imaging lens 210. At least one of the objective lens 206, the condenser lens 208, and the imaging lens 210 includes an optical element having the optical glass according to this embodiment as its base material. The following mainly describes the optical system of the multiphoton microscope 2.

[0076] The pulsed laser device 201 emits ultrashort pulsed light having, for example, a near-infrared wavelength (about 1000 nm) and a pulse width in femtosecond units (for example, 100 femtoseconds). The ultrashort pulsed light immediately after being emitted from the pulsed laser device 201 is generally linearly polarized in a predetermined direction.

[0077] The pulse splitting device 202 splits the ultrashort pulse light, increases the repetition frequency of the ultrashort pulse light, and emits it.

[0078] The beam adjusting unit 203 has a function of adjusting the beam diameter of the ultrashort pulsed light incident from the pulse splitter 202 to match the pupil diameter of the objective lens 206, a function of adjusting the focusing and divergence angles of the ultrashort pulsed light in order to correct the axial chromatic aberration (focus difference) between the wavelength of the multiphoton excitation light emitted from the sample S and the wavelength of the ultrashort pulsed light, and a pre-chirp function (group velocity dispersion compensation function) of imparting inverse group velocity dispersion to the ultrashort pulsed light in order to correct the pulse width of the ultrashort pulsed light being broadened due to group velocity dispersion while passing through the optical system.

[0079] The repetition frequency of the ultrashort pulsed light emitted from the pulsed laser device 201 is increased by the pulse dividing device 202, and the above-mentioned adjustment is performed by the beam adjusting unit 203. Then, the ultrashort pulsed light emitted from the beam adjusting unit 203 is reflected by the dichroic mirror 204 in the direction of the dichroic mirror 205, passes through the dichroic mirror 205, and is collected by the objective lens 206 to be irradiated onto the sample S. At this time, the ultrashort pulsed light may be scanned on the observation surface of the sample S by using a scanning means (not shown).

[0080] For example, when observing the fluorescence of a sample S, the fluorescent dye with which the sample S is stained undergoes multiphoton excitation in the area of ​​the sample S irradiated with the ultrashort pulsed light and in its vicinity, emitting fluorescence (hereinafter referred to as "observation light") having a wavelength shorter than that of the ultrashort pulsed light, which is an infrared wavelength.

[0081] Observation light emitted from the sample S in the direction of the objective lens 206 is collimated by the objective lens 206 and is either reflected by or transmitted through the dichroic mirror 205 depending on its wavelength.

[0082] The observation light reflected by the dichroic mirror 205 enters the fluorescence detection unit 207. The fluorescence detection unit 207 is composed of, for example, a barrier filter, a PMT (photomultiplier tube), etc., receives the observation light reflected by the dichroic mirror 205, and outputs an electrical signal according to the amount of light. Furthermore, the fluorescence detection unit 207 detects the observation light across the observation surface of the sample S as the ultrashort pulsed light scans the observation surface of the sample S.

[0083] On the other hand, the observation light that passes through the dichroic mirror 205 is descanned by a scanning means (not shown), passes through the dichroic mirror 204, is focused by the focusing lens 208, passes through a pinhole 209 located at a position approximately conjugate to the focal position of the objective lens 206, passes through an imaging lens 210, and enters the fluorescence detection unit 211.

[0084] The fluorescence detection unit 211 is composed of, for example, a barrier filter, a PMT, etc., receives the observation light imaged on the light receiving surface of the fluorescence detection unit 211 by the imaging lens 210, and outputs an electrical signal according to the amount of light. Furthermore, the fluorescence detection unit 211 detects the observation light across the observation surface of the sample S as the ultrashort pulsed light scans the observation surface of the sample S.

[0085] It is also possible to remove the dichroic mirror 205 from the optical path so that all of the observation light emitted from the sample S in the direction of the objective lens 206 is detected by the fluorescence detection unit 211 .

[0086] Moreover, the observation light emitted from the sample S in the direction opposite to the objective lens 206 is reflected by the dichroic mirror 212 and enters the fluorescence detection unit 213. The fluorescence detection unit 213 is composed of, for example, a barrier filter, a PMT, etc., receives the observation light reflected by the dichroic mirror 212, and outputs an electrical signal according to the amount of light. Moreover, the fluorescence detection unit 213 detects the observation light across the observation surface of the sample S as the ultrashort pulsed light scans the observation surface of the sample S.

[0087] The electrical signals output from the fluorescence detection units 207, 211, and 213, respectively, are input, for example, to a computer (not shown), and the computer can generate an observation image based on the input electrical signals, display the generated observation image, and store data of the observation image. EXAMPLES

[0088] Next, examples of the present invention and comparative examples will be described. The present invention is not limited to these examples. Optical glasses were prepared as follows, and their physical properties were evaluated.

[0089] <Production of optical glass> The optical glasses according to each of the examples and comparative examples were produced by the following procedure. First, glass raw materials selected from oxides, hydroxides, phosphate compounds (phosphates, orthophosphates, etc.), carbonates, sulfates, fluorides, and nitrates were weighed out to obtain the compositions shown in each table. Next, the weighed raw materials were mixed and put into a platinum crucible, melted at a temperature of 1100 to 1300°C for about 70 minutes, and stirred and homogenized. After bubble removal, the temperature was lowered to an appropriate level, and the mixture was cast into a mold and slowly cooled, followed by molding to obtain each sample.

[0090] <Refractive index (n d ) and Abbe number (ν d )> The refractive index of each sample was measured in accordance with the Japanese Industrial Standard JIS B 7071-1:2015 "Method of measuring the refractive index of optical glass". The refractive index (n d ) indicates the refractive index of glass for d-line light (wavelength 587.562 nm). d ) was calculated using the following formula (1). C , n F indicate the refractive index of glass for C line (wavelength 656.273 nm) and F line (wavelength 486.133 nm), respectively.

[0091] ν d =(n d -1) / (n F -n C) ···(1)

[0092] <Partial dispersion ratio (P g,F )> The partial variance ratio (P g,F ) is the principal variance (n F -n C ) for partial variance (n g -n F ) and was calculated using the following formula (2). g indicates the refractive index of glass for the g-line (wavelength 435.835 nm).

[0093] P g,F =(n g -n F ) / (n F -n C ) ···(2)

[0094] < Value indicating anomalous dispersion (ΔP g,F )> The value indicating the anomalous dispersion of each sample (ΔP g,F ) was determined in accordance with the method described below.

[0095] (1) Creating a reference line First, normal partial dispersion glass is used, with the Abbe number (ν d ) and partial variance ratio (P g,F Two glasses, "F2" and "K7", having Abbe numbers (ν d ) and the vertical axis is the partial variance ratio (P g,F ) was taken, and the straight line connecting the two points corresponding to the two reference materials was used as the reference line.

[0096] Characteristics of Glass "F2": d =36.33, P g,F =0.5834 Characteristics of glass "K7": d =60.47, P g,F =0.5429 Reference line: P g,F +0.00161783×ν d -0.64146248

[0097] (2)ΔP g,F Calculation of Next, the horizontal axis is the Abbe number (ν d ), and the vertical axis is the partial variance ratio (P g,F ), the values ​​corresponding to each glass were plotted on a graph, and the Abbe number (ν d ) and its vertical axis value (P g,F ) is the value indicating anomalous dispersion (ΔP g,F ) was calculated. FIG. 5 shows the Abbe number (ν d ) and partial variance ratio (P g,F The graph shows the partial variance ratio (P g,F ) is above the reference line, ΔP g,F has a positive value, and the partial variance ratio (P g,F ) is below the reference line, ΔP g,F has a negative value.

[0098] <Specific gravity (S g )> The specific gravity of each sample (S g ) was determined in accordance with the Japan Engineering Glass Industry Association standard JOGIS J05-1975 "Method of measuring specific gravity of optical glass."

[0099] < Glass transition temperature (T g )> The glass transition temperature (T g ) was calculated from the DTA curve obtained by measuring by differential thermal analysis (glass powder was placed in a Pt cell and the temperature was increased at a rate of 10° C. / min in air).

[0100] <Devitrification resistance test> Each sample was melted at 1050-1100°C for 30 minutes (without a lid), and then heated to the glass transition temperature (T g The temperature was then lowered to below 100° C. The presence or absence of devitrification at this time was visually evaluated according to the following criteria.

[0101] A: Only a very thin crystalline layer was present on the surface, and no crystal precipitation was observed inside.

[0102] B: Crystal precipitation was observed on the surface and in some parts of the interior.

[0103] C: The entire sample was devitrified, or the surface was devitrified, making it difficult to observe the inside.

[0104] The compositions and evaluation results of each of the examples and comparative examples are shown in Tables 1 to 11. n+ / F - As mentioned above, "F" is calculated based on atomic percent (at%). - Ti for the components 4+ Ingredients + Zr 4+ Ingredients + Nb 5+ Ingredients + Ta 5+ Ingredients + W 6+ component(ΣTM n+ ) percentage.

[0105] [Table 1]

[0106] [Table 2]

[0107] [Table 3]

[0108] [Table 4]

[0109] [Table 5]

[0110] [Table 6]

[0111] [Table 7]

[0112] [Table 8]

[0113] [Table 9]

[0114] [Table 10]

[0115] [Table 11]

[0116] The optical glass of this example was confirmed to have a high refractive index, low dispersion and high anomalous dispersion. It was also confirmed to have excellent resistance to devitrification and to be extremely useful in suppressing striae during glass production, particularly during melt molding.

[0117] In addition, the glass transition temperature (T g ) is high, the glass tends to solidify quickly. g ) is useful for suppressing striae. On the other hand, the glass transition temperature (T g ) has the advantage that it can be used suitably as a glass material for molding, which causes less damage to the mold due to heat. If such a need exists for the optical glass of this embodiment, it is preferable to use Li + The introduction of the glass transition temperature (T g ) to the lower temperature side. [Explanation of symbols]

[0118] 1...imaging device, 101...camera body, 102...lens barrel, 103...lens, 104...sensor chip, 105...glass substrate, 106...multichip module, 2...multiphoton microscope, 201...pulse laser device, 202...pulse splitter, 203...beam adjustment section, 204, 205, 212...dichroic mirror, 206...objective lens, 207, 211, 213...fluorescence detection section, 208...condenser lens, 209...pinhole, 210...imaging lens, S...sample, CAM...imaging device, WL...photographing lens, EF...auxiliary light emission section, LM...liquid crystal monitor, B1...release button, B2...function button

Claims

1. In mole percent of cations, P ５＋ Content rate: 30% or more but less than 45% A ３＋ Content rate: 10% or more but less than 20% Ba ２＋ Content: 20% or more and 40% or less, Contains at least one of Li + and Ti 4+ ; In mole percent of anion, O ２－ Content rate: 75% or more and 95% or less, F － Content: 5% or more and 25% or less; Abbe number (ν ｄ ) is 40 or more and 65 or less, Optical glass.

2. In mole percent of cations, P 5+ content: 30% or more and 45% or less, Al 3+ content: 10% or more and 20% or less, Ba2+ content: 20% or more and 40% or less; the total content (ΣTM n+ ) of Ti 4+ , ​​Zr 4+ , ​​Nb 5+ , Ta 5+ , and W 6+ is more than 0% and 10% or less; In mole percent of anion, O 2- content: 75% or more and 95% or less, F- content: 5% or more and 25% or less; the Abbe number (ν d ) is 40 or more and 65 or less; Optical glass.

3. Refractive index (n ｄ ) is 1.60 or more and 1.70 or less, 3. The optical glass according to claim 1 or 2.

4. ΔP ｇ，Ｆ is equal to or greater than 0.005 and equal to or less than 0.015; The optical glass according to any one of claims 1 to 3.

5. In mole percent of cations, Li ＋ Content: 1% or more and 6% or less; The optical glass according to any one of claims 1 to 4.

6. In mole percent of cations, Ti ４＋ Content: 0% or more and 6% or less; The optical glass according to any one of claims 1 to 5.

7. In mole percent of cations, Ti ４＋ Content: 0.5% or more and 6% or less; The optical glass according to any one of claims 1 to 6.

8. In mole percent of cations, Li ＋ Content: 0% or more and 6% or less; The optical glass according to any one of claims 1 to 7.

9. In mole percent of cations, Mg ２＋ Content rate: 0% or more but less than 15% Ca ２＋ Content rate: 0% or more but less than 20% SR ２＋ Content rate: 0% or more but less than 20% Zn ２＋ Content rate: 0% or more but less than 15% Y ３＋ Content rate: 0% or more but less than 6% La ３＋ Content rate: 0% or more but less than 6% Gd ３＋ Content rate: 0% or more but less than 6% Zr ４＋ Content rate: 0% or more but less than 3% Nb ５＋ Content rate: 0% or more but less than 8% Ta ５＋ Content rate: 0% or more but less than 4% W ６＋ Content: 0% or more and 6% or less; The optical glass according to any one of claims 1 to 8.

10. In mole percent of cations, P ５＋ and Al ３＋ Total content of (P ５＋ +Al ３＋ ) is 40% or more and 65% or less, The optical glass according to any one of claims 1 to 9.

11. In mole percent of cations, Mg ２＋ , Ca ２＋ , Sr ２＋ , Ba ２＋ and Zn ２＋ Total content (ΣAE ２＋ ) is 35% or more and 50% or less, The optical glass according to any one of claims 1 to 10.

12. In mole percent of cations, Y ３＋ , La ３＋ , and Gd ３＋ Total content (ΣRE ３＋ ) is 0% or more and 6% or less; The optical glass according to any one of claims 1 to 11.

13. In mole percent of cations, A ３＋ P content ５＋ Percentage of content (P ５＋ / Al ３＋ ) is 1.5 or more and 4.5 or less; The optical glass according to any one of claims 1 to 12.

14. In mole percent of cations, Mg ２＋ , Ca ２＋ and Sr ２＋ Ba relative to the total content ２＋ and Zn ２＋ Percentage of content (Ba ２＋ +Zn ２＋ ) / (Mg ２＋ +Ca ２＋ + Sr ２＋ ) is 0.5 or more and 10 or less; The optical glass according to any one of claims 1 to 13.

15. In mole percent of cations, P ５＋ and Al ３＋ Li relative to the total content ＋ , Mg ２＋ , Ca ２＋ , Sr ２＋ , Ba ２＋ , Zn ２＋ , Y ３＋ , La ３＋ , Gd ３＋ , Ti ４＋ , Zr ４＋ , Nb ５＋ , Ta ５＋ and W ６＋ The total content ratio ((Li ＋ +ΣAE ２＋ +ΣRE ３＋ +ΣTM ｎ＋ ) / (P ５＋ +Al ３＋ ) is 0.7 or more and 1.3 or less; The optical glass according to any one of claims 1 to 14.

16. Partial dispersion ratio (P ｇ，Ｆ ) is equal to or greater than 0.550 and equal to or less than 0.570; The optical glass according to any one of claims 1 to 15.

17. Specific gravity (S ｇ ) is 3.90 or more and 4.20 or less The optical glass according to any one of claims 1 to 16.

18. Glass transition temperature (T ｇ ) is 650 ° C or less; The optical glass according to any one of claims 1 to 17.

19. An optical element using the optical glass according to any one of claims 1 to 18.

20. 20. An optical system comprising the optical element according to claim 19.

21. An interchangeable lens comprising the optical system according to claim 20.

22. An optical device comprising the optical system according to claim 20.

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