To improve detection efficiency in a solid-state imaging element including a SPAD in which an electrode and wiring are placed in a central portion. A solid-state imaging element includes a photodiode and a light collecting section. The photodiode includes a light receiving surface and an electrode placed on the light receiving surface, and that outputs an electrical signal in accordance with light incident on the light receiving surface in a state where a voltage exceeding a breakdown voltage is applied to the electrode. The light collecting section causes light from a subject to be collected in the light receiving surface other than a region where the electrode is placed.

A microlens array includes N lenses ranging from a 1.sup.st lens to an N.sup.th lens and a lens arrangement area. N is a positive integer. The lens arrangement area has the N lenses arranged in array. The lens arrangement area receives light emitted from a light source. An i.sup.th (i being 1.sup.st to N.sup.th) lens satisfies a conditional expression below:

2020 where denotes an angle formed by a main-axis orientation of double refraction and a reference orientation.

An optical element includes a three-dimensional structure having a curved surface; and a retardation plate bent along the curved surface. The retardation plate includes a transparent substrate and a liquid crystal layer formed over the transparent substrate. The retardation plate has a slow axis and a fast axis. A glass-transition temperature, Tgne, in a slow axis direction of the retardation plate is higher than a glass-transition temperature, Tgno, in a fast axis direction of the retardation plate.

A microlens array includes N lenses ranging from a 1.sup.st lens to an N.sup.th lens and a lens arrangement area. N is a positive integer. The lens arrangement area has the N lenses arranged in array. The lens arrangement area receives light emitted from a light source. An i.sup.th (i being 1.sup.st to N.sup.th) lens satisfies a conditional expression below:
?20????20? where ? denotes an angle formed by a main-axis orientation of double refraction and a reference orientation.

A wafer level lens system includes a target lens and a wafer level lens group. The target lens includes a first surface, a second surface, and a first fitting structure. The second surface is opposite to the first surface. The first fitting structure is disposed at the second surface. The wafer level lens group includes a first transparent plate and a second fitting structure. The first transparent plate has a third surface and a fourth surface opposite to the third surface. The second fitting structure is disposed on the third surface. The first fitting structure is fitted into the second fitting structure, and there is a space encapsulated between the second surface and the third surface.

Various embodiments provide methods for fabricating a couplable electro-optical device. An example method comprises fabricating a pillar on a substrate by forming a lens spacer portion about an electro-optical component fabricated on the substrate; and adhering unshaped lens material to an exposed surface of the pillar. The exposed surface of the pillar is disposed opposite the substrate. The example method further comprises maintaining the unshaped lens material at a reflow temperature for a reflow time to allow the lens material to reflow into a formed lens shape, and curing the lens material to form an integrated lens having the formed lens shape secured to the lens spacer portion and formed about the electro-optical component on the substrate.

The present invention describes methods and apparatuses for creating superposition shape images by superposed base and revealing layers of lenslet gratings. The superposition shape images form a message recognizable by a human observer or by an image acquisition and computing device such as a smartphone. The superposition shape images may be created by different superposition techniques ranging from 1D moir, 2D moir and level-line moir superposition techniques to lenticular image and phase shift superposition techniques. Moir superposition techniques enable creating superposition shape images at different apparent depth levels. Applications comprise the protection of documents and valuable articles against counterfeits, the creation of eye-catching advertisements as well as the decoration of buildings and exhibitions.

The present technology relates to a lens array and a manufacturing method therefor, a solid-state imaging apparatus, and an electronic apparatus that can improve the AF performance while suppressing the deterioration of image quality. A lens array includes microlenses that are formed corresponding to phase difference detection pixels that are provided to be mixed in imaging pixels. Each of the microlenses is formed such that a lens surface thereof is a substantially spherical surface, the microlens has a rectangular shape in a planar view and four corners are not substantially rounded, and a bottom surface in vicinity of an opposite-side boundary portion that includes an opposite-side center portion of a pixel boundary portion in a cross-sectional view is higher than a bottom surface in vicinity of a diagonal boundary portion that includes a diagonal boundary portion. The present technology is applicable to a lens array of a CMOS image sensor, for example.

Described herein are embodiments of a diffractive optical element (23) such as a grism. In one embodiment, the diffractive optical element (23) includes an input surface (31) configured to receive an input optical signal (29), a diffractive surface (33) adapted to spatially disperse the input optical beam (29) into a dispersed signal and an output surface (35) configured to output the dispersed signal from the diffractive optical element. The input surface (31) and the diffractive surface (33) are non-parallel and the diffractive surface (33) is formed in situ by a photolithographic technique.

An optical element includes a three-dimensional structure having a curved surface; and a retardation plate bent along the curved surface. The retardation plate includes a transparent substrate and a liquid crystal layer formed over the transparent substrate. The retardation plate has a slow axis and a fast axis. A glass-transition temperature, Tgne, in a slow axis direction of the retardation plate is higher than a glass-transition temperature, Tgno, in a fast axis direction of the retardation plate.