To provide a near infrared cutoff filter glass which is excellent in optical properties such that the transmittance of light in the visible range is high and the transmittance of near infrared light is low. A near infrared cutoff filter glass comprising P, F, O, Cu and Ce, wherein by cation %, from 0.1 to 15% of Cu.sup.2+ is contained, and the ratio of Cu.sup.2+ to Ce.sup.4+ (Cu.sup.2+/Ce.sup.4+) is from 3.5 to 15.

An array of optical filters having a front side and a back side is disclosed. The array of optical filters includes first and second optical filters and a molding compound. The first and second optical filters each include a substrate having a back surface coplanar with the back side of the molding compound, and a filter layer having a front surface coplanar with the front side of the molding compound. The molding compound covers the sidewalls of the filter substrates and filter layers, and fills gaps between the filters.

The present invention provides a glass substrate in which in a heat treatment step of sticking a silicon substrate and a glass substrate to each other, an alkali ion is hardly diffused into the silicon substrate, and a residual strain generated in the silicon substrate is small. A glass substrate of the present invention has: an average thermal expansion coefficient α.sub.50/100 at 50° C. to 100° C. of 2.70 ppm/° C. to 3.20 ppm/° C.; an average thermal expansion coefficient α.sub.200/300 at 200° C. to 300° C. of 3.45 ppm/° C. to 3.95 ppm/° C.; a value α.sub.200/300/α.sub.50/100 obtained by dividing the average thermal expansion coefficient α.sub.200/300 at 200° C. to 300° C. by the average thermal expansion coefficient α.sub.50/100 at 50° C. to 100° C. of 1.20 to 1.30; and a content of an alkali metal oxide being 0% to 0.1% as expressed in terms of a molar percentage based on oxides.

According to at least one embodiment a glass comprises: a refractive index N of greater than 1.65 at a wavelength λ, where λ=587.6 nm; a glass density of not more than 4.2 g/cm.sup.3; Abbe number V.sub.d greater than 30; the glass comprising greater than 0.03 wt % of rare earth oxide with an atomic number of 58 or higher.

Disclosed is an optical-filter-cell-array structure and a method of manufacturing the same. An optical filter which includes an optical filter layer for blocking light of a specific wavelength formed on an upper side or a lower side of a tempered glass substrate is provided in the form of a cell array. The method includes forming a sheet-cutting part according to the form of a cell array on a mother glass substrate, tempering the mother glass substrate so that a lateral side of the mother glass substrate is tempered through the sheet-cutting part while an upper side and a lower side of the mother glass substrate are tempered, and forming an optical filter layer on the upper side or the lower side of the mother glass substrate.

A radiation image reading device includes: a light scanning unit; a light detection unit. Each of a transmittance when the excitation light reflected from the surface of the recording medium is transmitted through the optical filter and a transmittance when the signal light emitted from the surface of the recording medium at an angle larger than a predetermined angle with respect to a direction perpendicular to the scan line within the detection surface is transmitted through the optical filter is smaller than a transmittance when the signal light emitted from the surface of the recording medium at an angle smaller than the predetermined angle with respect to a direction perpendicular to the scan line within the detection surface is transmitted through the optical filter.

An optical arrangement for a camera module with an image sensor is provided. The optical arrangement includes optical components having a transparent cover element; an infrared absorbing cut-off filter; and an optical lens. The optical components are arranged, along an incident optical beam path going through the optical components onto the image sensor, in a sequence through the transparent cover element, then the infrared absorbing cut-off filter, and then the optical lens.

The present disclosure provides a near-infrared absorbing filter, including an absorbing type infrared filtering medium having opposite first and second surfaces; an organic coating layer formed on the first surface of the absorbing type filtering medium for absorbing infrared rays; a first multi-layered film structure formed on the organic coating layer with the organic coating layer disposed between the first multi-layered film structure and the absorbing type infrared filtering medium; and a second multi-layered film structure formed on the second surface of the absorbing type infrared filtering medium. The near-infrared filter of the present disclosure is able to reduce the wavelength difference of T50 and T20 of the incident light within the range of from 0 to 30 degrees to less than 5 nm, thereby reducing chromatic aberration effectively and reducing ghost images of infrared reflections. The disclosure further provides an image sensor including the near-infrared absorbing filter.

A lens barrel includes an optical element with a peripheral portion having a side face and a planar bottom face. The lens barrel includes a first member configured to position the side face in a direction orthogonal to an optical axis, and a second member configured to position the bottom face in a direction of the optical axis. The first member and the second member are fixed in a state in which the first member and the second member are positioned relative to each other in the direction of the optical axis with an abutting face of the first member and an abutting face of the second member being abutted on each other.

An optical component with improved degradation resistance is provided. The optical component includes an optical material and a coating. The optical material has a native surface that is susceptible to degradation processes. The coating is a layer of an inorganic material and is applied so as to be substantially contiguous so that there are no continuous paths between fluid surrounding the optical component and the optical material.