An optical device comprises two flat plates each having a reflective flat surface, and two flat spacer plates of thickness H each having a reflective sidewall. The flat plates and flat spacer plates are arranged as a stack with the reflective flat surfaces facing each other and the flat spacer plates arranged in a single plane and disposed between the two flat plates with the reflective sidewalls facing each other and with a gap between the two reflective sidewalls. The facing reflective flat surfaces and facing reflective sidewalls define a light tunnel passage with dimension H in the direction transverse to the single plane. The facing reflective sidewalls may be mutually parallel and spaced by a constant gap W to provide a light tunnel passage with constant cross-section H×W, or may be oriented at an angle to provide a tapered light tunnel passage.

An apparatus for generating extreme ultraviolet (EUV) radiation includes a droplet generator configured to generate target droplets. An excitation laser is configured to heat the target droplets using excitation pulses to convert the target droplets to plasma. A deformable mirror is disposed in a path of the excitation laser. A controller is configured to adjust parameters of the excitation laser by controlling the deformable mirror based on a feedback parameter.

A wavelength conversion element according to the present disclosure includes a cemented body obtained by bonding a first wavelength conversion member which is excited by first light to emit second light having a wavelength band different from a wavelength band of the first light, and a first light guide member configured to transmit the first light and the second light, and a reflecting member which is disposed so as to be opposed to at least one surface parallel to a first direction out of a plurality of outer circumferential surfaces of the cemented body, and reflects at least one of the first light and the second light.

A laser system may include a laser resonator configured to emit an input laser beam having an elliptical cross-sectional shape. The laser system also may include first reflective device configured to reflect the input laser beam to produce a first reflected laser beam. The first reflective device may include a spherical surface for reflecting the input laser beam. The laser system also may include a second reflective device configured to reflect the first reflected laser beam to produce a second reflected laser beam. The laser system also may include a coupling device configured to focus the second reflected laser beam to produce an output laser beam. The coupling device may include a spherical surface for receiving the second reflected laser beam. The laser system also may include an optic fiber configured to transmit the output laser beam for emission of the output laser beam onto a target area.

In a structural coloration substrate, a method for manufacturing the structural coloration substrate, and a security verification system using the structural coloration substrate manufactured by the method, the method includes forming a first pattern displaying a first color on a base substrate, using a quantum dot, and stacking at least one structural coloration layer on the base substrate on which the first pattern is formed. The first color of the first pattern is changed and displayed, as the at least one structural coloration layer is stacked.

Various embodiments include a camera with folded optics and lens shifting capabilities. In some examples, a folded optics arrangement of the camera may include one or more lens elements and light path folding elements (e.g., prisms). Some embodiments include voice coil motor (VCM) actuator arrangements, carrier arrangements, and/or suspension arrangements to provide autofocus (AF) and/or optical image stabilization (OIS) movement. Furthermore, some embodiments include position sensor arrangements for position sensing with respect to AF and/or OIS movement.

A low-profile eye-tracking system for an off-visor helmet-mounted display (HMD) includes annular illuminators clipped to, and aligned with, the terminal component (e.g., the emitter or combiner) of the HMD optical chain. The illuminators include visible-light or IR light sources mounted around the circumference of the illuminator for bouncing light off the visor's inner surface and into the pilot's left or right eye (the HMD may include separate eye-tracking systems for each eye). Image sensors are positioned to sequentially capture images of the illuminated eyes reflected off the visor surface. HMD onboard electronics analyze the captured image sequence to determine the azimuth and elevation of the pilot's eye relative to the centerline of the HMD optics.

An image display apparatus according to one embodiment of the present disclosure includes: an output section that outputs projection light along a predetermined axis; an irradiated member to be irradiated with the projection light; and a first optical member that is disposed downstream of the irradiated member on a light path of the projection light, and reflects or diffuses a portion of the projection light that has transmitted through the irradiated member.

An optical system includes an optical lens, a polarization volume hologram (PVH) layer arranged over the optical lens, and an IR absorbing structure arranged between the optical lens and the PVH layer. The PVH layer being configured to reflect infrared (IR) light. The IR absorbing structure includes a quarter-wave plate (QWP) arranged between the optical lens and the PVH layer and a linear absorptive polarizer arranged between the QWP and the optical lens. The linear absorptive polarizer is configured to absorb IR light.

Provided is a light source system, including: a light-emitting module configured to emit first light along a first light path and second light along a second light path; a wavelength conversion device configured to receive the first light and emit excited light with a color different from the first light; and a compensation device configured to guide the second light and adjust its luminous intensity distribution so that the luminous intensity distribution of the second light exiting from the compensation device is substantially identical to the excited light. The compensation device includes a compensation element configured to adjust luminous intensity distribution of a light beam so that an emergent light beam of the compensation element has reduced overall luminous intensity compared with an incident light beam. The second light exiting from the compensation device is combined with the excited light to form third light.