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 optical coating structure applied to the surface of an object having scattering structures introduced to the basal, upper or middle layers of a multilayer reflector to cause a particular (calculated) degree of scattering, or to the surface of a black/colour pigmented object. The scattering structures are mainly sub-micron in size, and arranged in a pseudo-random or non-periodic manner. Consequently they serve only to broaden the angular range of the light reflected at the surface normal from a multilayer reflector, or to provide (actual and/or perceived) reduced reflectivity of a surface by deflecting incident light through the surface rather than away from it or by scattering otherwise beam-like (narrow-angle) reflections from a surface into a broad-angle reflection. The scattering structures can include profile elements, which are in the form of elongate bars having convexly curved sides or hemispherical rods, that are introduced to a basal layer of a multilayer reflector.

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 semi-transparent mirror and method of producing the same are disclosed. An exemplary embodiment includes a coated article comprising a substrate, a first dielectric layer over at least a portion of the substrate, a second dielectric layer over at least a portion of the first dielectric layer, a third dielectric layer over at least a portion of the second dielectric layer, a fourth dielectric layer over at least a portion of the third dielectric layer, and a protective layer over at least a portion of the fourth dielectric layer.

A coated glass article includes a coating formed over a glass substrate. The coating comprises an optional base layer of an oxide of silicon, a first coating layer of an oxide of titanium, niobium or chromium, a second coating layer of an oxide of silicon, and a third coating layer of an oxide of tin. The coated glass article exhibits a Tvis of 40%-55% and an Rf of 40%-60%. A video display can be mounted behind the coated glass article, such that when the video display is in operation it is visible through the coated glass article and when the video display is not in operation is it concealed by the coated glass article.

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 Laser Induced Breakdown Spectroscopy (LIBS) probe using a dove prism for the laser media. The use of a dove prism allows for the removal of two mirrors over prior art schemes. The use of the dove prism allows for the light from the spark to be analyzed from the return path.

This invention relates to a cold mirror for a head-up display apparatus and provides a cold mirror that enables suppression of a phenomenon of change in color tone of an image depending on a position from which the image is viewed. This invention also provides a head-up display apparatus including the cold mirror. In a head-up display apparatus, display light of an image displayed on a display is reflected by a cold mirror and a reflected image of the image is viewed by a viewer. A relationship between an incident wavelength and a reflection phase difference in the cold mirror is set so that the reflection phase difference falls within a range of 18060 degrees for an entire visible wavelength range of 420 to 680 nm.

A display device includes a light source which provide a first light, a color filter including a plurality of quantum dots which absorbs the 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 between the light source and 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 high power handling optical modulator and methods of fabricating the same are described. The method includes forming a number of electrostatically deflectable elements over a surface of a substrate, and forming a non-metallic, multilayer optical reflector over each electrostatically deflectable element. The multilayer optical reflector includes at least a first layer of high index material having a high index of refraction, a second layer of a low index material having a low index of refraction formed over the first layer, and a third layer of high index material also having a high index of refraction formed over the second layer. Generally, the high index materials and low index material are selected and deposited to maintain planarity of the multilayer optical reflector at operating temperature. In one embodiment, the high and low index materials include silicon-germanium and air respectively. Other embodiments are also described.