A semiconductor light receiving device includes a substrate, a semiconductor fine line waveguide provided on the substrate, and a light receiving circuit that is provided on the substrate and that absorbs light propagating through the semiconductor fine line waveguide. The light receiving circuit includes a p type first semiconductor layer, a number of second semiconductor mesa structures provided on the p type first semiconductor layer in such a manner that an n type second semiconductor layer is provided on top of an i type second semiconductor layer, a p side electrode connected to the p type first semiconductor layer in a location between the second semiconductor mesa structures, and an n side electrode connected to the n type second semiconductor layer. The refractive index and the optical absorption coefficient of the second semiconductor layers are greater than the refractive index and the optical absorption coefficient of the first semiconductor layer.

A low loss high extinction ratio on-chip polarizer is disclosed. The polarizer includes an input waveguide taper having an outer waveguiding region that widens in the direction of light propagation along at least a portion of the taper length, and a core waveguiding region that narrows in the direction of light propagation along at least a portion of the taper length, so as to selectively squeeze out light of undesired modes into the outer regions while preserving light of a desired mode in the waveguide core. An integrated light absorber/deflector may be coupled to the outer waveguiding regions.

In a waveguide device, unnecessary optical power is appropriately terminated. According to an embodiment of the present invention, the waveguide device has a termination structure filled with a light blocking material to terminate light from a waveguide end. In the termination structure, a cladding and a core are removed to form a groove on an optical waveguide. The groove is filled with a material (light blocking material) that attenuates the intensity of light. Thus, light input to the termination structure is attenuated by the light blocking material, suppressing crosstalk which possibly effects on other optical devices. Thus, such a termination structure can restrain crosstalk occurred in optical devices integrated in the same substrate and can also suppress crosstalk which possibly effects on any other optical device connected directly to the substrate.

An imaging lens assembly includes a plurality of lens elements, a light path folding element and a sheet-like light blocking element. An optical axis is defined via the lens elements. The light path folding element includes an optical surface, and a total reflection of an imaging light of the imaging lens assembly occurs at least once on the optical surface. The sheet-like light blocking element is corresponding to the light path folding element, and the sheet-like light blocking element includes a first surface, a second surface and a microstructure layer. The first surface faces towards the optical surface. The second surface is disposed relatively to the first surface. The microstructure layer is at least disposed on the first surface, and protrusions are formed on the first surface via the microstructure layer. At least partial area between the microstructure layer and the optical surface has an air slit.

A photonic integrated circuit is provided that may include a substrate; one or more optical sources, on the substrate, to output light associated with a corresponding one or more optical signals; one or more waveguides connected to the one or more optical sources; a multiplexer connected to the one or more waveguides; and one or more light absorptive structures, located on the substrate adjacent to one of the one or more optical sources, one of the one or more waveguides, and/or the multiplexer, to absorb a portion of the light associated with at least one of the corresponding one or more optical signals.

In the present invention a new atomic clock is proposed comprising: at least one light source adapted to provide an optical beam, at least one photo detector and a vapor cell comprising a first optical window, said optical beam being directed through said vapor cell for providing an optical frequency reference signal, said photo detector being adapted to detect said optical frequency reference signal and to generate at least one reference signal, whereinsaid atomic clock comprises a first optical waveguide arranged to said first optical window, said first optical waveguide being arranged to incouple at least a portion of said optical beam, said first optical waveguide being sized and shaped so that said first guided light beam is expanded,a first outcoupler is arranged to outcouple at least a portion of said guided light beam to said vapor cell,the thickness t of the atomic clock is smaller than 15 mm.

In a waveguide device, unnecessary optical power is appropriately terminated. According to an embodiment of the present invention, the waveguide device has a termination structure filled with a light blocking material to terminate light from a waveguide end. In the termination structure, a cladding and a core are removed to form a groove on an optical waveguide. The groove is filled with a material (light blocking material) that attenuates the intensity of light. Thus, light input to the termination structure is attenuated by the light blocking material, suppressing crosstalk which possibly effects on other optical devices. Thus, such a termination structure can restrain crosstalk occurred in optical devices integrated in the same substrate and can also suppress crosstalk which possibly effects on any other optical device connected directly to the substrate.

The THz-wave device comprises: a 2D-PC slab; lattice points periodically arranged in the 2D-PC slab, the lattice points for diffracting the THz waves in PBG frequencies of photonic band structure of the 2D-PC slab in order to prohibit existence in a plane of the 2D-PC; a 2D-PC waveguide disposed in the 2D-PC slab and formed with a line defect of the lattice points; and an RTD device disposed on the 2D-PC waveguide.

A semiconductor light receiving device includes a substrate, a semiconductor fine line waveguide provided on the substrate, and a light receiving circuit that is provided on the substrate and that absorbs light propagating through the semiconductor fine line waveguide. The light receiving circuit includes a p type first semiconductor layer, a number of second semiconductor mesa structures provided on the p type first semiconductor layer in such a manner that an n type second semiconductor layer is provided on top of an i type second semiconductor layer, a p side electrode connected to the p type first semiconductor layer in a location between the second semiconductor mesa structures, and an n side electrode connected to the n type second semiconductor layer. The refractive index and the optical absorption coefficient of the second semiconductor layers are greater than the refractive index and the optical absorption coefficient of the first semiconductor layer.

A device includes a substrate and a dielectric layer on the substrate. The device also includes a light sensitive component in the dielectric layer and a trench having a first portion disposed in the substrate and a second portion disposed in the dielectric layer. The trench is adjacent the light sensitive component and includes an adhesion layer in the first portion and the second portion, an optical isolation layer on the adhesion layer, and a first fill material in the first portion and a second fill material in the second portion. The first fill material is characterized by a first coefficient of thermal expansion (CTE) that matches a CTE of the substrate and the second fill material is characterized by a second CTE that matches a CTE of the dielectric layer.