JP2020064156A - Optical element and manufacturing method thereof - Google Patents

Abstract

To provide an optical element more preferable in terms of surface hardness.SOLUTION: The optical element contains a chalcogenide material and/or a calcohalide material, which has an oxygen-containing layer 21 of chalcogenide material and/or calcohalide material over the outermost surface. The oxygen-containing layer has a nanoindenter hardness of 2.5 GPa to 4.5 GPa.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an optical element and a manufacturing method thereof. More specifically, it relates to an optical element that contributes at least to light transmission, and also to a manufacturing method for manufacturing such an optical element.

  Optical elements made of a resin material, a glass material, or the like have been used for various purposes. For example, the optical element is used as an optical fiber, a lens, or the like.

  In recent years, optical elements are also used in the optical sensing field such as an optical sensor for a monitoring system for disaster prevention and crime prevention, or an in-vehicle sensor module for a driving support system.

JP, 2008-107835, A International Publication No. 2017/022638

  The surface of an optical element used as a lens of an optical sensor is required to have high hardness. When the surface hardness of the optical element is low, the surface of the optical element may be cracked or scratched when mounted on the sensor and / or used.

  The inventor of the present application realized that the previously proposed optical element still had a problem to be overcome, and found that it is necessary to take measures against it. Specifically, the inventor of the present application has found out that there are the following problems.

  The chalcogenide material and the chalcogenide material, which are excellent in terms of wavelength transparency, have a lower hardness than an optical element using an oxide glass material or the like. Therefore, higher hardness of the surface is required. For example, as shown in FIG. 5, as one configuration for increasing the hardness of the surface of the optical element, a hard coat layer, a diamond-like carbon (DLC) layer, or the like is formed on the surface of the base material portion 52 of the optical element 50. It is proposed that the thin film layer 51 is formed (see Patent Document 1 and Patent Document 2).

  However, in such a hardened layer, the material used is limited due to the interaction with the optical element, so that the desired hardness may not be obtained.

  In view of the above problems, the present disclosure aims to provide an optical element having better surface hardness.

  The inventor of the present application tried to solve the above-mentioned problems by addressing the problem in a new direction, rather than as an extension of the conventional technique. As a result, the invention of the optical element has been achieved in which the above-mentioned main object is achieved.

  In order to achieve the above object, an optical element is provided in the present disclosure. Such an optical element contains a chalcogenide material and / or a chalcogenide material, and has an oxygen-containing layer of the chalcogenide material and / or the chalcogenide material on the outermost surface portion. The nano indenter hardness of the oxygen-containing layer is 2.5 GPa to 4.5 GPa. The present disclosure also provides a method for manufacturing the above optical element. In the method for producing an optical element, the optical element contains a chalcogenide material and / or a chalcogenide material, and the chalcogenide material and / or the chalcogenide material on the outermost surface portion of the optical element is subjected to an oxygen-containing treatment for containing oxygen.

  The optical element of the present disclosure has better surface hardness. Specifically, the surface hardness of the optical element can be increased by forming the oxygen-containing layer on the outermost surface portion of the optical element.

Sectional drawing which showed typically the optical element which concerns on one Embodiment of this indication. Sectional drawing which showed typically the lens which is an optical element which concerns on one Embodiment of this indication. A graph showing the reflectance of an optical element according to an embodiment of the present disclosure. Graph showing the nano indenter hardness of the optical element before and after the surface treatment according to an embodiment of the present disclosure Sectional drawing which showed typically the optical element which formed the thin film layer on the surface.

  Below, the manufacturing method of the optical element of this indication and the optical element obtained by the manufacturing method are demonstrated in detail. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters or duplicate description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the description and facilitate understanding by those skilled in the art.

  Applicants provide the accompanying drawings and the following description for a person skilled in the art to fully understand the present disclosure, and are not intended to limit the claimed subject matter by these. It should be noted that the various elements in the drawings are merely schematically and exemplarily shown for understanding of the manufacturing method and the optical element of the present disclosure, and the appearance and the dimensional ratio may be different from the actual ones.

  In the present specification, “cross-sectional view” is based on a virtual cross section obtained by cutting along the thickness direction of the optical element. In other words, the sketch drawing in the cross section cut along the thickness of the optical element corresponds to the “cross sectional view”. Typically, the “thickness direction of the optical element” may correspond to the light transmission direction of the optical element.

[Characteristics of Optical Element of Present Disclosure]
The optical element of the present disclosure is an optical element containing a chalcogenide material and / or a chalcogenide material, and is characterized by the composition of the outermost surface portion thereof.

  More specifically, the optical element of the present disclosure contains a chalcogenide material and / or a chalcogenide material, and has an oxygen-containing layer of the chalcogenide material and / or the chalcogenide material on the outermost surface portion thereof. The oxygen-containing layer is formed by performing an oxygen-containing treatment on the outermost surface portion of the optical element. Since the oxygen-containing layer has a lower refractive index with respect to the base material portion of the optical element, it has a better surface antireflection function. Further, the oxygen-containing layer has a higher hardness than the base material portion of the optical element, and thus has a better surface hardness. Furthermore, since the oxygen-containing layer has high adhesion to the base material portion of the optical element and has a coefficient of thermal expansion equivalent to that of the base material portion, delamination or the like during processing or use can be suitably suppressed. .

  The “optical element” in the present disclosure means a member for transmitting light. Therefore, the optical element is, for example, a lens, a prism, or a mirror, and may be, for example, a window product related to light transmission.

  The "oxygen-containing layer of chalcogenide material and / or chalcogenide material" in the present disclosure is, in a broad sense, containing oxygen by modifying the outermost surface portion of the optical element containing the chalcogenide material and / or chalcogenide material. A layer that has been subjected to an oxygen-containing treatment. In a narrow sense, the term "oxygen-containing layer of chalcogenide material and / or chalcogenide material" means not only a layer in which a material composition containing a chalcogenide material and / or a chalcogenide material and oxygen form a compound, It refers to a layer in which any atom of the material composition containing the chalcogenide material and / or the chalcogenide material is replaced with an oxygen atom. As for the latter, at least a part of the chalcogen element and / or the halogen element of the chalcogenide material and / or the chalcogenide material may be replaced with oxygen.

  The "outermost surface portion" as used herein refers to a peripheral portion (that is, the outermost layer) of the surface of the optical surface in the optical element. In the illustrated embodiment, the oxygen-containing layer 21 corresponds to the outermost surface portion in the cross-sectional view of the optical element 20 shown in FIG.

  As used herein, the term “chalcogenide material” means, in a broad sense, at least one chalcogen element selected from the group consisting of S (sulfur), Se (selenium), and Te (tellurium) in the VIb group of the periodic table. Means a material containing as one of the main components. For example, in the chalcogenide material, at least one chalcogen element selected from the group consisting of S (sulfur), Se (selenium) and Te (tellurium) is Ge (germanium), As (arsenic), Sb (antimony), P It may be a material having a composition in combination with at least one selected from the group consisting of (phosphorus), Ga (gallium), In (indium) and Si (silicon). The term “chalcogenide material” as used herein means that a halogen element (at least one selected from the group consisting of fluorine, chlorine, bromine and iodine) or a compound thereof is introduced into such a chalcogenide material. A material having a composition such as

  In the exemplary embodiment shown in FIG. 1, the oxygen-containing layer 21 is provided on the outermost surface portion of the optical element 20. That is, the optical element 20 includes at least the oxygen-containing layer 21 and the base material portion 22.

  The oxygen-containing layer 21 and the base material portion 22 have a high mutual interaction due to their composition. Specifically, the oxygen-containing layer 21 is a layer that has been subjected to an oxygen-containing treatment for modifying the outermost surface portion of the optical element 20 to contain oxygen, in other words, the same material composition as the base material portion 22. Since it is a layer based on, the oxygen-containing layer 21 and the base material portion 22 have strong adhesion strength (see FIG. 1). That is, the outermost surface portion of the optical element can be provided with an oxygen-containing layer in which peeling hardly occurs during processing or use. Therefore, the optical element can be provided with a good surface antireflection function, and can also be provided with a high hardness surface. Further, it becomes possible to suitably suppress delamination of the optical element during processing or use.

  The oxygen-containing layer 21 may have an oxygen concentration gradient in which the oxygen concentration gradually decreases in the thickness direction with the outermost surface being the maximum value (see FIG. 1). Since the oxygen-containing layer 21 has such an oxygen concentration gradient, it is possible to mitigate a sudden change in the material structure between the base material portion 22 and the oxygen-containing layer 21 in the optical element 20. Therefore, the adhesion between the base material portion 22 and the oxygen-containing layer 21 in the optical element 20 can be further improved.

  The optical element 20 may be a lens, an optical filter, or the like formed of a base material containing a chalcogenide material and / or a chalcogenide material. The surface of the optical element 20 may be a flat surface as shown in FIG. 1 or may be a curved surface forming the lens 25 as shown in FIGS. 2A to 2C. The lens 25 includes a light transmitting portion 26 that functions as an optical element to transmit light, and a flange portion 27 that functions to hold the lens 25 and the like.

  In one embodiment, the oxygen-containing layer 21 is a low reflection layer. Since the oxygen-containing layer 21 is a low reflection layer, the surface reflection of the optical element 20 can be prevented and the light amount of the desired wavelength light can be secured. The oxygen-containing layer 21 may be a layer different from the optical element 20 in terms of refractive index, and may be configured to cancel surface reflection of light having a predetermined wavelength. Further, additionally / or alternatively, it may be configured to reduce the reflection by absorbing a light beam having a predetermined wavelength.

  In one embodiment, the oxygen-containing layer 21 has a hardness higher than that of the base material portion 22 of the optical element 20. Therefore, the oxygen-containing layer 21 is a hardened layer. Since the oxygen-containing layer 21 is a hardened layer, it is possible to prevent cracks and scratches on the surface of the optical element 20 during mounting on a sensor and / or during use.

  In one embodiment, the oxygen-containing layer 21 has a nanoindenter hardness of 2.5 GPa to 4.5 GPa. When the nano indenter hardness is 2.5 GPa or more, the optical element 20 can have a sufficient hardness, and cracks or scratches on the surface of the optical element 20 occur during mounting on a sensor and / or during use. Can be prevented. On the other hand, when the nanoindenter hardness is 4.5 GPa or less, brittleness of the optical element 20 can be further suppressed, and chipping during mounting on a sensor or the like and / or during use can be prevented. The nano indenter hardness is preferably 2.6 GPa to 4.4 GPa, for example 2.7 GPa to 4.3 GPa.

  In one embodiment, the nano indenter hardness ratio of the oxygen-containing layer 21 to the base material portion 22 of the optical element 20 is 1.1 to 1.7. When the nano indenter hardness ratio is 1.1 or more, it is possible to particularly prevent the surface of the optical element 20 from being cracked or scratched during mounting on a sensor and / or during use. On the other hand, when the nanoindenter hardness ratio is 1.7 or less, stress concentration on the base material portion 22 can be particularly prevented during processing or use. The nanoindenter hardness ratio is preferably 1.2 to 1.65, for example 1.3 to 1.6.

  In the present specification, the nanoindenter hardness of the base material portion 22 and the oxygen-containing layer 21 of the optical element 20 may be obtained by a nanoindenter measuring instrument. Specifically, using a Nanoindenter G200 (Birkovich type indenter) manufactured by Keysight Technologies, Inc., the nanoindenter hardness of the surface depth of 100 nm and the surface depth of 1000 nm in the optical element 20 is measured, and the surface depth is 100 nm. The measured value at 2 may be the nano indenter hardness of the oxygen-containing layer 21, and the measured value at a surface depth of 1000 nm may be the nano indenter hardness of the base material portion 22. The nano-indenter hardness ratio of the oxygen-containing layer 21 to the base material portion 22 of the optical element 20 refers to a value obtained by dividing the measured nano-indenter hardness of the oxygen-containing layer 21 by the nano-indenter hardness of the base material portion 22. It may be one.

  In one embodiment, the oxygen-containing layer 21 has a thickness of 10 nm to 5 μm. When the thickness is 10 nm or more, it is possible to more effectively prevent the surface reflection of a light beam having a predetermined wavelength in the optical element 20, and it is possible to further increase the hardness. The thickness is, for example, 100 nm or more from the viewpoint of particularly increasing the hardness of the optical element 20. On the other hand, when the thickness is 5 μm or less, absorption of infrared rays by the oxygen-containing layer 21 in the optical element 20 can be prevented more effectively. The thickness is, for example, 3 μm or less from the viewpoint of particularly preventing absorption of infrared rays. Further, the thickness is, for example, 1000 nm or less from the viewpoint of particularly preventing the deterioration of the surface shape such as the surface roughness of the optical element 20.

  In one embodiment, the chalcogenide material and / or chalcogenide material included in the optical element 20 is a sulfide-based material. Since the chalcogenide material and / or chalcogenide material is a sulfide-based material, toxicity is lower than that of other chalcogen-based materials, and absorption on the short wavelength side can be suppressed to be small.

  As a specific composition of the oxygen-containing layer 21, at least one selected from the group consisting of Ge: 2 to 22%, Sb and Bi in molar concentration: 6 to 34%, Sn: 1 to 20%, S, It may be at least one kind selected from the group consisting of Se and Te: 58 to 70%, and O: 1 to 70%. With such a composition, the transmittance of the optical element 20 can be further increased. Also, additionally / or alternatively, the oxygen-containing layer 21 can have higher hardness. Further, additionally / or alternatively, the formability of the optical element 20 can be improved more effectively.

  In one embodiment, in the oxygen-containing layer 21, at least a part of the chalcogen element and / or the halogen element of the chalcogenide material and / or the chalcogenide material is replaced with oxygen. The oxygen-containing layer 21 having such a structure can further reduce the refractive index of the oxygen-containing layer 21. Also, additionally / or alternatively, the hardness can be higher. Further, additionally / or alternatively, the adhesion of the optical element 20 to the base material portion 22 can be further increased.

  In the present specification, the composition and thickness of the oxygen-containing layer 21 may be those obtained by composition analysis in the depth direction by X-ray photoelectric spectroscopy (XPS). Specifically, the composition of the oxygen-containing layer 21 is measured by XPS measurement of the oxygen-containing layer 21 using an X-ray photoelectron spectrometer (PHI-1800; manufactured by ULVAC-PHI Co., Ltd.) and Ar sputtering for the oxygen-containing layer 21. The composition and the chemical bonding state may be obtained by measuring the photoelectron spectrum in the depth direction of the oxygen-containing layer 21 while alternately repeating and, and analyzing from the photoelectron spectrum. The thickness of the oxygen-containing layer 21 may be a value obtained by calculating the thickness of the oxygen-containing layer 21 from the oxygen concentration profile obtained from the photoelectron spectrum in the depth direction.

  In one embodiment, the refractive index ratio of the oxygen-containing layer 21 to the base material portion 22 of the optical element 20 is 0.4 to 0.9. When the refractive index ratio is 0.4 to 0.9, it is possible to more effectively prevent the surface reflection of light having a predetermined wavelength. The refractive index ratio is preferably 0.5 to 0.8, for example 0.55 to 0.75.

  In this specification, the refractive index ratio of the oxygen-containing layer 21 to the base material portion 22 of the optical element 20 may be obtained by a refractive index measuring device. Specifically, the refractive index of the base material portion 22 and the oxygen-containing layer 21 may be measured using a spectroscopic ellipsometer (Smart SE manufactured by HORIBA scientific). The refractive index ratio of the oxygen-containing layer 21 to the base material portion 22 of the optical element 20 may be a value obtained by dividing the measured refractive index of the oxygen-containing layer 21 by the refractive index of the base material portion 22.

  In one embodiment, the average reflectance in the visible light region of the optical element 20 is 1% to 25%. Here, the "visible light region" refers to a wavelength band of 380 nm to 780 nm. With such an average reflectance, a sufficient amount of light can be secured for visible light sensing and real image acquisition, and thus can be particularly suitably used for an optical sensor for a disaster prevention / crime prevention monitoring system.

  In one embodiment, the average reflectance of the optical element 20 in the infrared region is 1% to 35%. Here, the “infrared region” refers to a wavelength band of 8 μm to 12 μm. By having such an average reflectance, a more sufficient amount of light can be secured for infrared radiation thermometers and dark field image acquisition, and therefore, it can be particularly suitably used for an in-vehicle sensor module for a driving support system or the like. .

  In the present specification, the average reflectance in the visible light region and the infrared region may be obtained by a spectrophotometer. Specifically, the average reflectance in the visible light region is obtained by measuring the spectral reflectance at a wavelength of 380 nm to 780 nm at a wavelength of 40 nm using a reflectance meter (Olympus "USPM-RUIII"). May be the average value of. The average reflectance in the infrared region is obtained by measuring the spectral reflectance at a wavelength of 8 μm to 12 μm at an interval of 100 nm using an infrared spectrophotometer (“270-30” manufactured by Hitachi, Ltd.). May be the average value of.

  The optical element 20 of the present disclosure may be a lens for transmitting a light ray in at least an infrared region. In particular, it may be a lens used for an optical sensor for a disaster prevention / crime prevention monitoring system and / or an on-vehicle sensor module for a driving support system.

  The chalcogenide material of the present disclosure has suitable transmission characteristics in the infrared region, and the chalcogenide material can have suitable transmission characteristics not only in the infrared region but also in the visible light region. The optical element can have the optical characteristics as described above.

[Method for manufacturing optical element of the present disclosure]
The manufacturing method according to the present disclosure is a method of manufacturing the optical element 20. In particular, the present disclosure manufactures an optical element 20 that includes a chalcogenide material and / or a chalcogenide material by an oxygen-containing treatment. The chalcogenide material and the chalcogenide material are materials composed of non-oxides, and the feature of the manufacturing method of the present disclosure is that the optical element 20 including these materials is subjected to the oxygen-containing treatment.

  Specifically, the chalcogenide material and / or the chalcogenide material and / or the chalcogenide material on the outermost surface portion of the optical element 20 containing the chalcogenide material is subjected to an oxygen-containing treatment for containing oxygen.

  In one embodiment, the oxygen-containing treatment is performed so that the nanoindenter hardness of the outermost surface portion of the optical element is 2.5 GPa to 4.5 GPa.

  As a method of forming the oxygen-containing layer 21 on the outermost surface portion of the optical element 20, a method of irradiating ultraviolet rays in the presence of oxygen and / or ozone, a thermal oxidation method of annealing in the presence of oxygen, an oxygen ion or oxygen plasma on the surface is used. A method of irradiating, a method of leaving in an atmosphere in the presence of oxygen, and / or a method of contacting with water can be used, but the present disclosure is not limited to these methods.

  Since the oxygen-containing treatment of the present disclosure is a method of modifying such a surface by the surface treatment of the optical element 20 as described above, as shown in the exemplary embodiment of FIG. It is possible to form the oxygen-containing layer 21 having an oxygen concentration gradient in the thickness direction. Since the oxygen-containing layer 21 has such an oxygen concentration gradient, it is possible to mitigate a sudden change in the material structure between the base material portion 22 of the optical element 20 and the oxygen-containing layer 21. Therefore, the adhesion between the base material portion 22 of the optical element 20 and the oxygen-containing layer 21 can be further improved.

  In one embodiment, as the oxygen-containing treatment, the surface of the optical element 20 is irradiated with ultraviolet rays in the presence of oxygen. By irradiating with ultraviolet light in the presence of oxygen, active oxygen (O) in an excited state having a strong oxidizing power can be produced. Such active oxygen (O) can form a functional group on the outermost surface portion of the optical element 20, and can provide the oxygen-containing layer 21 having a higher interaction with the base material portion 22 of the optical element 20.

  In one embodiment, the surface of optical element 20 is further exposed to ozone. As such ozone exposure, UV irradiation may be performed in the presence of oxygen and ozone, or the surface of the optical element 20 that has been UV-irradiated in the presence of oxygen may be further UV-irradiated in the presence of ozone. When exposed to ozone, more active oxygen (O) can be produced, and the oxygen-containing layer 21 having a higher interaction with the base material portion 22 of the optical element 20 can be provided.

  In one embodiment, as the oxygen-containing treatment, the surface of the optical element 20 is annealed in the presence of oxygen. Since the annealing in an oxygen atmosphere can be performed only by heating the optical element 20 in an oven or the like, the oxygen-containing treatment can be performed more easily and inexpensively.

  The oxygen-containing treatment may be applied to both of the two facing outermost surface portions of the optical element, or may be applied to only one of the two facing outermost surface portions. Alternatively, it may be attached only to the outermost surface portion of the light transmitting portion of the lens which is the optical element. Here, “two opposing outermost surface portions” correspond to the uppermost outermost surface portion and the lowermost outermost surface portion of the optical element 20 in the exemplary embodiment shown in FIG. 1. In addition, the “outermost surface portion of the light transmitting portion of the lens that is the optical element” corresponds to the outermost surface portion of the light transmitting portion 26 of the lens 25 in the exemplary embodiment shown in FIG. 2C. In the exemplary embodiment shown in FIGS. 2A to 2C, in the lens 25, the oxygen-containing layer 21 may be provided on both of the two outermost surface portions that face each other (FIG. 2A), and only one of the outermost surface portions may contain oxygen. The containing layer 21 may be provided (FIG. 2B), or only the outermost surface portion of the light transmitting portion 26 may be provided with the oxygen containing layer 21 (FIG. 2C).

  The optical element 20 is molded into a shape according to its application. For example, the shape of the optical element 20 is a plate shape in an optical filter, an infrared transmission window, or the like, and is a concavo-convex shape (a biconcave shape, a biconvex shape, etc.) in a lens such as a sensor. The material may be molded into the shape of the optical element 20 by any method such as grinding / polishing and / or press molding.

  When the optical element is a lens, the optical element may be formed from a material by, for example, mold press molding. Hereinafter, such a molding method will be described as an example. First, the material is pre-molded into a substantially final shape by injection molding. Next, the preformed material is stored in the cavity of the optical element molding die that is heated to a temperature above the deflection temperature under load of the material and below the glass transition temperature. Then, when the temperature of the raw material becomes substantially equal to or higher than the deflection temperature under load and lower than the glass transition temperature substantially in agreement with the optical element molding die, the deformation is maintained by pressing the raw material while lowering the press head. Next, the applied pressure is released, the temperature is lowered to the deflection temperature under load, and the optical element is taken out of the optical element molding die, whereby an optical element molded into a desired shape (for example, a lens shape) can be obtained.

  Hereinafter, the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[Fabrication of Optical Element of Present Disclosure]
An infrared transmission filter IIR-SF2 (manufactured by Isuzu Seiko Glass Co., Ltd.), which is a sulfide-based chalcogenide material, was used as an optical element, and the surface of the optical element was subjected to ultraviolet irradiation in the atmosphere. Ultraviolet irradiation was performed using a low-pressure mercury lamp (200 W, 185 nm wavelength component 30% manufactured by Sen Special Light Source Co., Ltd.), and the three optical element samples were respectively irradiated for 30 minutes, 1 hour, and 5 hours.

[Measurement of reflectance]
The visible light reflectance of each optical element sample was measured using a reflectance measuring device (Olympus "USPM-RUIII") at a wavelength of 380 nm to 780 nm at an incident angle Φ = 0 degree. The reflectance of each optical element sample at wavelengths of 380 nm to 780 nm is shown in FIG.

  As shown in FIG. 3, in all the optical element samples, the reflectance was decreased in the entire wavelength range of 380 nm to 780 nm. In addition, the UV irradiation time increased and the reflectance decreased. Therefore, it was found that the optical element can be provided with a good surface antireflection function by being subjected to the oxygen-containing treatment.

[Optical simulation of reflectance]
The reflectance at a wavelength of 380 nm to 780 nm was calculated by optical simulation using the physical property values measured from the optical element sample that was subjected to ultraviolet irradiation for 5 hours. As the physical property values, the refractive index of the base material portion of the optical element: 3.10, the refractive index of the oxygen-containing layer: 1.99, and the oxygen-containing layer thickness: 112 nm were used. Regarding the results, as shown in FIG. 3, the measured value and the calculated value by the optical simulation are in good agreement, and the desired reflectance preventing function can be obtained by forming the oxygen-containing layer 21 on the surface of the optical element 20. I found out.

[Measurement of nano-indenter hardness]
The measurement of the nano indenter hardness was performed using a Nanoindenter G200 manufactured by Keysight Co., Ltd. using a Berkovich type indenter. The indentation depth in the measurement was set to 750 nm and the hardness was calculated. The nano indenter hardness of the optical element having the oxygen-containing treatment time of 5 hours is shown in FIG.

  As shown in FIG. 4, the sample of the optical element 20 showed an increase in surface hardness. Particularly in the outermost layer to 100 nm, a remarkable increase in surface hardness was exhibited. Therefore, it was found that by forming the oxygen-containing layer 21 on the surface of the optical element 20, a high surface hardness can be imparted to the optical element 20.

  The embodiments have been described above, but they are merely typical examples. Therefore, those skilled in the art will easily understand that the manufacturing method and the optical element of the present disclosure are not limited to this and various modes are conceivable.

  As described above, according to the present disclosure, in particular, an optical sensor for a disaster prevention / crime prevention monitoring system, and / or a vehicle-mounted sensor module for a driving support system, a high-quality imaging optical system, an objective optical system, and a scanning optical system. System, various optical systems such as a pickup optical system, various optical units such as an optical element barrel unit, an optical pickup unit, an image pickup unit, and an image pickup device, an optical pickup device, an optical scanning device, and the like.

20 optical element 21 oxygen-containing layer 22 base material part 25 lens 26 light transmitting part 27 flange part

Claims (13)

An optical element,
Including chalcogenide material and / or chalcogenide material,
An optical element having an oxygen-containing layer of the chalcogenide material and / or the chalcogenide material on the outermost surface portion, and the nano-indenter hardness of the oxygen-containing layer is 2.5 GPa to 4.5 GPa. The optical element according to claim 1, wherein the oxygen-containing layer has a thickness of 0.1 μm to 5 μm. The optical element according to claim 1, wherein a nanoindenter hardness ratio of the oxygen-containing layer to the base material portion of the optical element is 1.1 to 1.7. The optical element according to claim 1, wherein the chalcogenide material and / or the chalcogenide material is a sulfide system. The optical element according to claim 1, wherein at least a part of the chalcogen element and / or the halogen element of the chalcogenide material and / or the chalcogenide material is replaced with oxygen in the oxygen-containing layer. The optical element according to any one of claims 1 to 5, wherein the optical element is a lens for transmitting a light ray in at least an infrared region. A manufacturing method for manufacturing an optical element, comprising:
The optical element contains a chalcogenide material and / or a chalcogenide material,
The chalcogenide material and / or the chalcogenide material of the outermost surface portion of the optical element is subjected to an oxygen-containing treatment for containing oxygen, and the oxygen-containing treatment causes the nanoindenter hardness of the outermost surface portion to be 2.5 GPa to 4 The manufacturing method of an optical element which makes it 5 GPa. The method for manufacturing an optical element according to claim 7, wherein the surface of the optical element is irradiated with ultraviolet rays in the presence of oxygen as the oxygen-containing treatment. The method for manufacturing an optical element according to claim 8, wherein the surface of the optical element is further exposed to ozone. The method of manufacturing an optical element according to claim 7, wherein the surface of the optical element is annealed in an oxygen atmosphere as the oxygen-containing treatment. The optical element according to any one of claims 7 to 10, wherein a nanoindenter hardness ratio of the outermost surface portion to the base material portion of the optical element is set to 1.1 to 1.7 by the oxygen-containing treatment. Production method. The oxygen-containing treatment replaces at least a part of the chalcogen element and / or the halogen element of the chalcogenide material and / or the chalcogenide material of the outermost surface portion with oxygen. Manufacturing method. The manufacturing method according to claim 7, wherein a lens for transmitting at least a light ray in an infrared region is manufactured as the optical element.

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