An optical element is provided. The optical element includes an optical film including a birefringent material having a chirality. Optically anisotropic molecules of the birefringent material disposed adjacent a first surface of the optical film are configured with a first pretilt angle in a range of greater than 10° and less than 80°, or in a range of greater than −80° and less than −10°. Optically anisotropic molecules of the birefringent material disposed adjacent a second surface of the optical film opposing the first surface are configured with a second pretilt angle in the range of greater than 10° and less than 80°, or in the range of greater than −80° and less than −10°.

A phase change filter is formed by an arrangement of dots, wherein each dot is made of a phase change material. A heating layer of electrically conductive material extends under the arrangement of dots. Current passing through the heating layer changes the dots between two states to alter attenuation of light passing through the filter.

A display device includes a backlight and a display panel on the backlight. The backlight includes a light source to provide a first light, and an optical wavelength converter to receive the first light and emits a second light. The optical wavelength converter includes a light emitting part having a plurality of excitation light emitting bodies to be excited by receiving the first light, and thereby emit the second light, and a light absorbing part including a plurality of absorbers provided on the light emitting part to receive the second light and absorb a portion of the second light having a wavelength of about 550 nm to about 650 nm.

In various embodiments, the present disclosure provides devices and systems for detecting the blood pressure of a user. In one embodiment, an optoelectronic device includes an array of avalanche photodiodes operating in Geiger mode. A tunable optical filter is optically coupled to the array and receives a light beam reflected from a vascularized tissue of the user, in response to the vascularized tissue being illuminated by an optical source.

A system is described that combines spectropolarimetry with scatterometry. The system uses an annular mirror and liquid crystal devices to control the angle of the incident light cone, the polarization and wavelength, an imaging setup and one or more video cameras so that spectroseopic-polarimetric-scatterometric images can be grabbed rapidly. The system is also designed to incorporate additional imaging modes such as interference, phase contrast, fluorescence and Raman spectropolarimetric imaging.

An apparatus for a combined camera system is described herein. The apparatus includes an adjustable infrared (IR) pass filter. A passband of the adjustable infrared (IR) pass filter is electrically adjusted. The apparatus also includes a rolling shutter sensor. An adjustable filter is to implement a global shutter and a rolling shutter sensor global reset.

In the step of curing a resin for bonding a TFT substrate and a counter substrate each having an alignment film that has been optically aligned by using UV-light, damage to the alignment film due to the UV-light can be prevented without using a light shielding mask. A UV-light absorption layer is formed between each black matrix on the counter substrate. The TFT and counter substrates are sealed at their periphery by a resin that is cured by UV-light radiated from the counter substrate side. Since the absorption layer has a high absorbability to UV-light at a wavelength of 300 nm or less that degrades the alignment film, damage to the alignment film due to the UV-light for curing the resin can be prevented. Thus, provision of a light shielding mask for shielding the UV-light for the display region can be saved.

A tunable spectral filter includes a first tunable dispersive element, a first optical element, a spatial filtering element located at the focal plane, a second optical element, and a second dispersive element. The first tunable dispersive element introduces spectral dispersion to an illumination beam with an adjustable dispersion. The first optical element focuses the illumination beam at a focal plane in which a distribution of a spectrum of the spectrally-dispersed illumination beam at the focal plane is controllable by adjusting the dispersion of the first tunable dispersive element. The spatial filtering element filters the spectrum of the illumination beam based on the distribution of the spectrum of the illumination beam at the focal plane. The second optical element collects the spectrally-dispersed illumination beam transmitted from the spatial filtering element. The second tunable dispersive element removes the dispersion introduced by the first tunable dispersive element from the illumination beam.

An embodiment of the present invention discloses a reflective type display device, relating to the technical field of display. The liquid crystal display device is relatively thin and light, with low energy consumption. The reflective type display device comprises a polarizer, a transparent first substrate, a liquid crystal molecular layer and a second substrate arranged in sequence; wherein the reflective type display device further comprises: a selective reflecting layer located between the liquid crystal molecular layer and the second substrate; the selective reflecting layer reflects light with wavelength within a specific wavelength range.

An infrared optical filter may include a glass ceramic layer, a multilayer oxide thin film formed on a first surface of the glass ceramic layer, and a low reflectivity coating layer formed on a second surface of the glass ceramic layer.