Methods and devices for a plasmonic circuit are described. A planar plasmonic device is configured with a controlling gate structure and when coupled to a complementary plasmonic device, a switching circuit can be realized. Also, by varying the properties of the complementary plasmonic device, the circuit can also operate as an amplifier. By use of combinations of this plasmonic circuit element, more advanced circuits and logic functions can be arrived at.

A device and system for coupling optical vortex multiplexed light into and out of a photonic integrated circuit. The multi-mode forked grating coupler device comprises: (i) a multi-mode forked grating structure configured to receive at least one optical vortex multiplexed light beam, wherein the multi-mode forked grating structure comprises at least one forked region positioned amidst a plurality of grooves, wherein the forked region comprises a single groove forking into two grooves, wherein the single groove is noncontiguous with the two grooves, and wherein the plurality of grooves comprise a central bending region; (ii) an optical waveguide; and (iii) a tapered portion connecting the forked grating structure and the multi-mode optical bus waveguide

A device and system for coupling optical vortex multiplexed light into and out of a photonic integrated circuit. The multi-mode forked grating coupler device comprises: (i) a multi-mode forked grating structure configured to receive at least one optical vortex multiplexed light beam, wherein the multi-mode forked grating structure comprises at least one forked region positioned amidst a plurality of grooves, wherein the forked region comprises a single groove forking into two grooves, wherein the single groove is noncontiguous with the two grooves, and wherein the plurality of grooves comprise a central bending region; (ii) an optical waveguide; and (iii) a tapered portion connecting the forked grating structure and the multi-mode optical bus waveguide

An integrated optical device includes a substrate, a waveguide structure and a grating structure. The substrate has a waveguide region and a grating region adjacent to each other. The waveguide structure is disposed on the substrate in the waveguide region. The grating structure is disposed on the substrate in the grating region. In some embodiments, the grating structure includes grating bars and grating intervals arranged alternately, and widths of the grating bars of the grating structure are varied.

An integrated optical device includes a substrate, a waveguide structure and a grating structure. The substrate has a waveguide region and a grating region adjacent to each other. The waveguide structure is disposed on the substrate in the waveguide region. The grating structure is disposed on the substrate in the grating region. In some embodiments, the grating structure includes grating bars and grating intervals arranged alternately, and widths of the grating bars of the grating structure are varied.

The present invention provides compositions comprising human placental telopeptide collagen, methods of preparing the compositions, methods of their use and kits comprising the compositions. The compositions, kits and methods are useful, for example, for augmenting or replacing tissue of a mammal.

An external resonator type light-emitting device includes a light source oscillating a semiconductor laser light and a grating element configuring an external resonator together with the light source. The light source includes an active layer oscillating said semiconductor laser light. The grating element includes an optical waveguide and a plurality of Bragg gratings formed in the optical waveguide. The optical waveguide includes an incident face to which the semiconductor laser light is incident and an emitting face from which an emitting light having a desired wavelength is emitted. A half value reflectance R.sub.50 is larger than a reflectance R.sub.2 at an emitting end of the light source. A half value reflectance R.sub.50 is 3% or larger. A combined reflectance is not less than the half value reflectance R.sub.50 in a wavelength region .sub.50. The wavelength region .sub.50 is continuous over 10 nm or more and 30 nm or less, provided that a half value reflectance is defined as 50 percent of a maximum value Rmax of the combined reflectance of the Bragg gratings.

A semiconductor device including an optical waveguide and a p-type semiconductor portion is configured as follows. The optical waveguide includes: a first semiconductor layer formed on an insulating layer; an insulating layer formed on the first semiconductor layer; and a second semiconductor layer formed on the insulating layer. The p-type semiconductor portion includes the first semiconductor layer. The film thickness of the p-type semiconductor portion is smaller than that of the optical waveguide. By forming the insulating layer between the first semiconductor layer and the second semiconductor layer, control of the film thicknesses of the optical waveguide and the p-type semiconductor portion is facilitated. Specifically, when the unnecessary second semiconductor layer is removed by etching in a step of forming the p-type semiconductor portion, the insulating layer which is the lower layer functions as an etching stopper, and the film thickness of the p-type semiconductor portion can be easily adjusted.

A laser source or a plurality of laser sources in a photonic integrated circuit (PIC) are provided with an electrical contact that is either segmented or is connected to a series of vernier resistor segments for supply of current to operate the laser source. In either case, at least one segment of the laser contact or at least one vernier resistor segment can be trimmed in order to vary the amount of current supplied to the laser source resulting in a change to its current density and, thus, a change in its operational wavelength while maintaining the current supplied to the laser source constant.

A laser source or a plurality of laser sources in a photonic integrated circuit (PIC) are provided with an electrical contact that is either segmented or is connected to a series of vernier resistor segments for supply of current to operate the laser source. In either case, at least one segment of the laser contact or at least one vernier resistor segment can be trimmed in order to vary the amount of current supplied to the laser source resulting in a change to its current density and, thus, a change in its operational wavelength while maintaining the current supplied to the laser source constant.