A bandpass filter may include a set of layers. The set of layers may include a first subset of layers. The first subset of layers may include hydrogenated germanium (Ge:H) with a first refractive index. The set of layers may include a second subset of layers. The second subset of layers may include a material with a second refractive index. The second refractive index may be less than the first refractive index.

An EUV collector for use in an EUV projection exposure apparatus includes at least one mirror surface having surface structures for scattering a used EUV wavelength () of used EUV light. The mirror surface has a surface height with a spatial wavelength distribution between a lower limit spatial wavelength and an upper limit spatial wavelength. An effective roughness (rmsG) below the lower limit spatial wavelength (PG) satisfies the following relation: (4 rmsG cos()/)2<0.1. denotes an angle of incidence of the used EUV light at the mirror surface. The following applies to an effective roughness (rmsGG) between the lower limit spatial wavelength (PG) and the upper limit spatial wavelength (PG): 1.5 rmsG<rmsGG<6 rmsG.

An aerospace mirror having a reaction bonded (RB) silicon carbide (SiC) mirror substrate, and a SiC cladding on the RB SiC mirror substrate forming an optical surface on a front side of the aerospace mirror. A method for manufacturing an aerospace mirror comprising obtaining a green mirror preform comprising porous carbon, silicon carbide (SiC), or both, the green mirror preform defining a front side of the aerospace mirror and a back side of the aerospace mirror opposite the front side; removing material from the green mirror preform to form support ribs on the back side; infiltrating the green mirror preform with silicon to create a reaction bonded (RB) SiC mirror substrate from the green mirror preform; forming a mounting interface surface on the back side of the aerospace mirror from the RB SiC mirror substrate, and forming a reflector surface of the RB SiC mirror substrate on the front side of the aerospace mirror. Additionally, the method can comprise cladding the reflector surface of the RB SiC mirror substrate with SiC to form an optical surface of the aerospace mirror.

A device includes a ceramic substrate formed of a first material, a polishable layer formed of a different material, and an interface between the ceramic substrate and the polishable layer. The interface is formed by infiltration of molten elemental silicon, and bonds the ceramic substrate and the polishable layer together. The device may include an optical device such as, for example, mirror or a beam dump. A method of making a device from a green-state structure and a polishable layer is also disclosed. The method includes infiltrating elemental silicon into and through the green-state structure, to form a substrate of a multi-phase ceramic material from the green-state structure, and to reactively bond the substrate and the polishable layer together.

An optical stacking structure includes a color filter including a plurality of quantum dots which absorbs a first light and emits at least one of second light and third light that are different from the first light, a first optical filter layer disposed on the color filter, and a second optical filter layer disposed on the opposite side of the first optical filter based on the color filter. The first optical filter blocks at least a part of the first light, and the second optical filter transmits at least a part of the first light and reflects at least a part of the second light and the third light.

A dielectric mirror includes a coating having alternating high and low index layers. The mirror coating has no metallic reflective layer of Al or Ag in certain example embodiments, and may have film side and/or glass side visible reflection of from about 50-90% (more preferably from about 60-80% and most preferably from about 65-75%) and visible transmission of from about 10-50% (more preferably from about 10-40% or 20-40%) in certain example embodiments.

A dielectric mirror is provided that, on the one hand exhibits a high destruction threshold when being irradiated with ultrashort high-power laser pulses, and on the other hand has a large bandwidth of group delay dispersion. The dielectric mirror includes a layer stack with a sequence of layers having different refractive indices, which act as a reflecting interference filter, wherein the layers are formed of at least three different materials exhibiting different destruction thresholds.

According to one embodiment, a medical imaging apparatus includes a gantry, a carriage, a screen, a reflector, and a frame. The gantry has a bore formed therein. The bore is formed to accept a subject to be imaged by the medical imaging apparatus. The carriage moves through the bore. The screen is provided on the carriage. An image is projected on the screen by a projector from a rear. The rear is opposite to a side of which a top plate is inserted into the bore. The reflector reflects the image projected on the screen. The reflector includes prisms arranged in a same line. The frame supports the reflector. The frame is provided on the carriage.

Embodiments of the present disclosure are directed toward an optical apparatus that includes a semiconductor layer to propagate light from at least one light source. The optical apparatus may further include a curved echelle grating with a plurality of grating teeth, the echelle grating at an outer side of the semiconductor layer. The curved echelle grating may include a plurality of grating teeth, and a grating tooth of the plurality of grating teeth may have a grating facet and a shadow facet. A shadow facet may have an angle of grating greater than 0 degrees with respect to a normal of a curve of the curved echelle grating. Other embodiments may be described and/or claimed.

A reflective mirror is provided with a base and a multilayer film including a first layer and a second layer laminated alternately on the base and capable of reflecting at least a portion of incident light. The multilayer film is provided with a first portion having a first thickness, and with a second portion having a second thickness that is different from the first thickness, and which is provided at a position rotationally symmetric to that of the first portion about an optical axis of the reflective mirror.