An optical filter includes a first layer including a first notch filter arranged to attenuate electromagnetic radiation having a first wavelength λ.sub.1 incident normally thereupon. The optical filter includes a second layer including a second notch filter arranged to attenuate electromagnetic radiation having a second wavelength λ.sub.2 incident normally thereupon. The first wavelength λ.sub.1 and the second wavelength λ.sub.2 are different. The second layer is stacked upon the first layer. In use, the first notch filter attenuates the electromagnetic radiation having a predetermined wavelength λ incident thereupon at a first angle of incidence θ.sub.1 and the second notch filter attenuates the electromagnetic radiation having the predetermined wavelength λ incident thereupon at a second angle of incidence θ.sub.2, wherein the first angle of incidence θ.sub.1 and the second angle of incidence θ.sub.2 are different.

Active optical filter adapted for a spectacle lens, the active optical filter being configured so as to filter light radiations over at least one predetermined range of wavelengths, wherein the full width at half maximum of the filtering function of the optical filter is smaller than or equal to 100 nm.

A filter device for an optical sensor, including a hologram having a defined number of holographic functions, which are developed in such a way that the filter device blocks optical radiation that impinges upon the filter device from a defined first solid angle and optical radiation that impinges upon the filter device from a defined second solid angle is able to pass through the filter device.

The object of the present invention is to provide an optical information medium having a colored glossy effect which is single- or multi-colored in regions where a reflective layer is present, but colorless in regions where the reflective layer is absent. The optical information medium of the present invention includes a bonding part (receiving layer), at least one image part, and an adhesive layer (protective layer) covering the at least one image part, wherein each of the image part includes a micro-protrusion/depression structure including part having a micro-protrusion/depression structure on at least a part of the surface opposite to the bonding part, a reflective layer, and a mask layer, in the order from the bonding part (receiving layer), the micro-protrusion/depression structure including part is colorless or colored in one or more translucent or opaque color, and at least one of the micro-protrusion/depression structure including part of the image part is colored in one or more translucent or opaque color.

An optical device includes: a light guide plate receiving, for each of N types of wavelength bands, a plurality of parallel light beams with different incident angles each corresponding to view angles, and guiding the received parallel light beams; a first and a second volume hologram gratings of reflection type having a diffraction configuration which includes N types of interference fringes each corresponding to the N types of wavelength bands, and diffracting/reflecting the parallel light beams. The optical device satisfies for each wavelength band, a relationship of ‘P>L’, where ‘L’ represents a central diffraction wavelength in the first and second volume hologram gratings, defined for a parallel light beam corresponding to a central view angle, and ‘P’ represents a peak wavelength of the parallel light beams.

Methods of manufacturing an optical device can include, in some implementations, providing a substrate having a first polymeric layer on a surface of the substrate and a second polymeric layer on the first polymeric layer, forming first openings in the second polymeric layer to define an etch mask composed of material of the second polymeric layer, and etching to form second openings in the first polymeric layer, wherein locations of the second openings are defined by the etch mask. A material is deposited in the second openings to form meta-atoms of a first metastructure, wherein adjacent ones of the meta-atoms are separated from one another by polymeric material of the first polymeric layer. Optical devices including metastructures can be formed, where meta-atoms of the metastructure have a relatively high aspect ratio.

An optical combiner includes a first layer with a periodic arrangement of structures of a material with a first refractive index. A second layer overlies the structures on the first layer, and the second layer includes a material with a second refractive index. A difference between the first refractive index and the second refractive index, measured at 587.5 nm, is less than 1.5. The periodic arrangement of structures is configured such that the optical combiner produces, for an input signal incident on the first layer from air at an oblique elevation angle of greater than 20°, an output signal with three reflection peaks, each reflection peak having an average reflection of greater than 50% within a ±3° range of the elevation angle.

A method includes receiving collimated light from an optical imaging system and dividing the received light into multiple bands of wavelength. Each band is refocused onto a corresponding diffraction grating having an amplitude function matched to a point spread function (PSF) of the optical imaging system. The light that is not filtered out by the diffraction grating is transmitted onto a corresponding pixel array. An image is reconstructed from data provided by the pixel arrays for each band. The intensity of light scattered by each diffraction grating may be detected, with the image being reconstructed as a function of an average value of detected intensity of scattered light used to scale the known zero-order mode profile, which is added to the image on the pixel array.

Real-space optical signal processing is provided by optical angular filters that act on amplitude and/or phase of zero order light passing through a resonant diffractive optical device. One application is to phase contrast microscopy, where the diffractive optical device can be configured to have an amplitude and phase response suitable for phase contrast microscopy. For example, 60% or more intensity attenuation of the zero order light, combined with a phase shift of the zero order light by +/−90 degrees.

An optical isolation element comprising, sequentially: a light control film; a first optical path changing element; and a second optical path changing element. The optical isolation element has an excellent optical isolation ratio, and can be manufactured simply and at low cost. Such an optical isolation element can be applied, for example, to the fields of optical communication or laser optics, security and privacy protection, and members for brightness enhancement in displays or military products requiring hiding and covering, and the like.