11 results about "Dielectric mirror" patented technology

A multiband dichroic metamirror includes a dielectric mirror and a metasurface. The dielectric mirror is configured to split incident light into a first waveband and a second waveband. The dielectric mirror is also configured to transmit the first waveband with a high transmission value and to reflect the second waveband with a high reflection value. The metasurface acts as a diffractive optical element that is configured to provide optical power for the second waveband.

Described is a semiconductor chip (1) comprising a semiconductor body (2) having a first semiconductor layer (21) of a first conductivity type, a second semiconductor layer (22) of a second conductivity type different from the first conductivity type, and an active region (20) configured for emitting radiation, the active region (20) is arranged between the first semiconductor layer (21) and the second semiconductor layer (22), the first semiconductor layer (21) being electrically connected to a first contact structure (3) comprising at least one first contact finger (31); -at least one first contact finger (31) comprises a contact layer (35) and a current distribution layer (36); -the contact layer (35) is arranged on the first semiconductor layer (21); a dielectric mirror (4) is arranged in a region between the contact layer (35) and the current distribution layer (36); -the dielectric mirror (4) comprises at least one opening (41); and-the current distribution layer (36) extends through the at least one opening (41) and is directly adjacent to the contact layer (35).

A magnetic resonance examination system has an examination region (11) and comprises a camera (21) and a non-metallic mirror (22), in particular within the examination region (11), through which a light path (23) is arranged between a portion of the examination region (11) and the camera (21). The camera can obtain image information from the portion even if a direct line of sight (28) is blocked. The non-metallic mirror is a dielectric mirror having a macroscopic grid base.

A tunable optical filter with a top-hat pass band shape. The proposed tunable optical filter is adapted to be installed over a top surface of a sensor, and comprises a set of at least three stacked dielectric mirrors parallelly adjacent to the plane of installation of the sensor, the at least three stacked dielectric mirrors comprise an upper mirror, an intermediate mirror and a lower mirror, wherein the set of at least three stacked mirrors is spaced within a variable distance to create at least two independent and adjacently equal volumetry cavities between the upper mirror and the intermediate mirror and between the intermediate mirror and the lower mirror.

An optical waveguide combiner having an output coupler comprising an array of embedded partially reflective dielectric mirrors expanding and coupling a virtual, optionally color, image generated by a laser display engine into a user EMB, wherein the dielectric mirrors are configured having a wavelength band for each lasing band of the laser display engine that includes wavelengths of light in the lasing band and in a range of wavelengths over which the lasing band is expected to drift, a reflectivity angular range exhibiting a first reflectivity, a transmittance angular range exhibiting a second reflectivity less than the first reflectivity, and a see-thru angular transmittance range having high transmittance for natural light incident on the facets.

A multiband dichroic metamirror (102) includes a dielectric mirror (300) and a metasurface (302). The dielectric mirror is configured to split incident light (110) into a first waveband (112) and a second waveband (114). The dielectric mirror is also configured to transmit the first waveband with a high transmission value and to reflect the second waveband with a high reflection value. The metasurface acts as a diffractive optical element that is configured to provide optical power for the second waveband.

The invention discloses an optical fiber ultrasonic endoscope of an array type detector and a preparation method of the optical fiber ultrasonic endoscope, and belongs to the field of ultrasonic endoscopic imaging. Comprising an optical fiber ultrasonic transmitter, an optical fiber ultrasonic detector and a clamp. The part, close to the end face, in the optical fiber ultrasonic transmitter is of a conical structure, and the conical structure is combined with an excitation film based on the photoacoustic effect to form a circular-ring-shaped ultrasonic excitation unit. In the optical fiber ultrasonic detector, a dielectric mirror and a sensing film are utilized to form a Fabry-Perot (F-P) interference cavity which is used for ultrasonic detection. The optical fiber ultrasonic transmitter penetrates through the hollow structure of the clamp, the array type optical fiber ultrasonic detector is fixed in the groove in the periphery of the clamp, and the optical fiber ultrasonic endoscope of the array type detector is formed. The optical fiber conical structure is combined with the excitation film to achieve annular ultrasonic excitation, the clamp is used for forming the array type optical fiber ultrasonic detector to achieve annular ultrasonic detection, the optical fiber ultrasonic endoscope of the array type detector is formed, and the optical fiber ultrasonic endoscope can be applied to rapid imaging of blood vessels or tiny cavities.

A low-loss bidirectional HE11 coupler is disclosed with substantially higher directivity than prior HE11 THz couplers for overmoded waveguides operating in a frequency band centered about f0, where f0 is between 0.03 to 1.5 THz, with mid-band free-space wavelength λ0. The coupler comprises a main hollow-metal waveguide, aligned along the z axis, of inner radius r1, where r1 is greater than 2λ0, a first end of the main waveguide is identified as port-1 and its second end is identified as port-2. A first transverse lofted transition waveguide couples a port-3 of radius r3, where r3<r1, to a substantially elliptical opening of mean radius greater than r3 in one side of the main waveguide. A similar second tapered lofted transition waveguide, aligned on the same axis as the first lofted transition, identified as the y axis, couples a port-4 to a substantially elliptical opening in the opposite side of the main waveguide. A substantially elliptical dielectric mirror, centered with respect to the intersection of the axes of the main waveguide and the transverse coupling waveguides, rotated at approximately 45° with respect to the xy plane about the x axis for HE11 E-field polarization in the y direction, supported on its +x and −x sides, has major and minor transverse dimensions sufficient to intersect a substantial fraction of the cross-sectional area of the beam in the main waveguide. The mirror is further characterized as having thickness greater than λm / 10 and less than λm, where λm is the wavelength in the mirror at f0. The mirror dielectric is further characterized as typically having dielectric constant εm less than 3.7 and loss tangent less than 0.02. The coupler is further characterized as having portions of the inside surfaces of waveguides near their intersections coated with a microwave absorptive material that is characterized as having loss tangent greater than 0.01 and thickness greater than λa / 5, where λa is the wavelength in the absorptive coating at f0. Other inner surfaces of the waveguides may be bare metal, or corrugated, or laminate lined. A polarizer may be included at port-1 and / or port-2 to partially block s-polarization, here polarization with E field in the x direction. The polarizer may be formed by etching an array of narrow traces on copper-clad low-loss laminate of substrate thickness approximately λp / 2, where λp is the wavelength in the polarizer substrate at f0. The traces are further characterized as having periodicity approximately λ0 / 4, trace width less than λ0 / 12, and being aligned in the x direction.

This invention discloses an all-fiber ultrasonic endoscope and imaging system, belonging to the field of ultrasonic endoscopic imaging. It includes a guide fiber, a dielectric mirror, a sensing film, a heat-insulating film, an excitation film, a focusing acoustic reflector, and a lateral guide tube. Excitation laser light passes through the dielectric mirror, sensing film, and heat-insulating film, is absorbed by the excitation film, and generates ultrasonic waves, which are then transmitted laterally out of the endoscope through the lateral opening of the lateral guide tube. The Fabre-Perot cavity formed by the dielectric mirror causes multi-beam interference of the signal light, modulating the ultrasonic wave signal laterally transmitted into the endoscope onto the intensity of the interference light. This invention forms an integral structure by sequentially covering the end face of the guide fiber with the dielectric mirror, sensing film, heat-insulating film, and excitation film, and then fixing the guide fiber, focusing acoustic reflector, and lateral guide tube together. This reflects the ultrasonic waves propagating along the guide fiber to the side, allowing the fiber optic ultrasonic endoscope to simultaneously achieve lateral excitation and lateral detection of ultrasonic waves using a single optical fiber.

The invention relates to a surface emitter having a first dielectric mirror structure, a second dielectric mirror structure and a light emitting structure arranged vertically between the first dielectric mirror structure and the second dielectric mirror structure, the light emitting structure being provided for emitting light. The first dielectric mirror structure and the second dielectric mirror structure are arranged to reflect light emitted by the light emitting structure. The light emitting structure has or is formed of at least one epitaxially grown layer. At least one of the first dielectric mirror structure and the second dielectric mirror structure does not have an epitaxially grown layer.