Integrated active photonic device such as optical amplifiers, lasers, light emitters, photodetectors, optical modulators, optical switches, plasmonic devices, all-optical devices, and active photonic devices with high efficiency capable of very low power consumption, low optical loss, and small device size are of interest. An efficient optical waveguide structure for achieving high overlapping between the optical beam mode and the active electro-active region leads to reduced power consumption, low optical loss, and small device size. In an embodiment, low power consumption, low optical loss, and small device size are enabled by a semiconductor active photonic device structure, together with an active semiconductor material that is an electro-optic or electro-absorption or gain material, that are appropriately doped with carriers to substantially lower the power consumption and still maintain the high device performance. In another embodiment, an efficient optical coupling structure further enables low optical loss. Various embodiments combined enable the active photonic device to reach lower power consumption, lower optical loss, and smaller device size than previously possible in the prior arts.

An optical coupling system to couple a collimated beam with a waveguide made of semiconductor materials is disclosed. The waveguide is implemented in an optical modulator and/or an optical hybrid, and has a core with a restricted cross section because of the enhanced refractive index of the semiconductor materials. The collimated beam is focused on the core by the two-lens system including first and second lenses. The first lens, having a focal length shorter than a focal length of the second lens, is first aligned with the core, then, the second lens is aligned with the core as compensating deviations of the first lens induced during the fixation thereof.

The present invention provides an optical modulator, which can be reduced in size with size reduction of an optical waveguide and electric wiring as compared to a conventional optical modulator. An optical modulator according to an embodiment includes a substrate; an optical waveguide provided on the substrate and configured to guide light; a modulation unit formed of part of the optical waveguide and configured to modulate the light; and electric wires provided on the substrate and configured to supply a high-frequency electric signal to the modulation unit. One end portion and another end portion of the optical waveguide are provided on a first end surface, one end portion of the electric wiring is provided along the first end surface, another end portion of the electric wiring is provided along a second end surface being different from the first end surface.

An EA modulator having a structure in which an increased optical confinement factor is provided. An optical modulator having a high-mesa structure made of an InP-based materials, including: a waveguide core having a multi quantum well structure; a lower selective etching layer inserted into a lower cladding at an interval from the waveguide core; and an upper selective etching layer inserted into an upper cladding at an interval from the waveguide core, where the lower selective etching layer and the upper selective etching layer are narrower than a mesa width of the high-mesa structure.

A light modulation element constituted by a substrate type optical waveguide has a Mach-Zehnder interferometer; and a traveling wave electrode having a signal electrode arranged at least between a first phase modulator and a second phase modulator and electrically connected to both of the first phase modulator and the second phase modulator. A polarity of a semiconductor region of the first phase modulator connected to the signal electrode and a plurality of a semiconductor region of the second phase modulator connected to the signal electrode are different from each other.

Various Reservoir Computing systems and a method performed by a Reservoir Computing system are provided. A Reservoir Computing system includes a laser for emitting light. The Reservoir Computing system further includes a mirror for reflecting external feedback light back to the laser. The Reservoir Computing system also includes a modulator for modulating the external feedback light reflected back to the laser. The Reservoir Computing system additionally includes a photo-detector for converting a laser output signal to an electrical signal.

There is provided an illumination device comprising: a wavelength converting layer comprising a photon emitting donor configured to absorb energy to reach an excited state, and a photon emitting acceptor; an energy source configured to provide energy to the donor such that the donor reach the excited state; wherein the donor and the acceptor are selected and arranged at a distance from each other such that non-radiative transfer of excitation energy from the donor to the acceptor occur, and wherein the acceptor is configured to emit a photon at a second wavelength after the transfer of energy; the illumination device further comprising a periodic plasmonic antenna array, arranged on the substrate and embedded within the wavelength converting layer, and comprising a plurality of individual antenna elements arranged in an antenna array plane, the plasmonic antenna array being configured to support a first lattice resonance at the second wavelength, arising from coupling of localized surface plasmon resonances in the individual antenna elements to photonic modes supported by the system comprising the plasmonic antenna array and the wavelength converting layer, wherein the plasmonic antenna array is configured to comprise plasmon resonance modes such that light emitted from the plasmonic antenna array has an anisotropic angle distribution.

An optical coupling system to couple a collimated beam with a waveguide made of semiconductor materials is disclosed. The waveguide is implemented in an optical modulator and/or an optical hybrid, and has a core with a restricted cross section because of the enhanced refractive index of the semiconductor materials. The collimated beam is focused on the core by the two-lens system including first and second lenses. The first lens, having a focal length shorter than a focal length of the second lens, is first aligned with the core, then, the second lens is aligned with the core as compensating deviations of the first lens induced during the fixation thereof.

The present invention provides a functional film having an optical functional layer that exhibits an optical function and is capable of suppressing deterioration of the optical functional layer, and a method thereof. The functional film includes an optical functional layer, a resin layer which surrounds end surfaces of the optical functional layer, and gas barrier supports between which the optical functional layer and the resin layer are sandwiched, in which an oxygen permeability of the resin layer is 10 cc/(m.sup.2.Math.day.Math.atm) or less, and a difference between a thickness of the optical functional layer and the resin layer is within 30%; and a production method including forming a frame-shaped resin layer on a surface of a first gas barrier support, filling the inside of the frame with a polymerizable composition which becomes an optical functional layer, laminating a second gas barrier support on the resin layer, and curing the polymerizable composition.

Integrated optical intensity or phase modulators capable of very low modulation voltage, broad modulation bandwidth, low optical power loss for device insertion, and very small device size are of interest. Such modulators can be of electro-optic or electro-absorption type made of an appropriate electro-optic or electro-absorption material in particular or referred to as an active material in general. An efficient optical waveguide structure for achieving high overlapping between the optical beam mode and the active electro-active region leads to reduced modulation voltage. In an embodiment, ultra-low modulation voltage, high-frequency response, and very compact device size are enabled by a semiconductor modulator device structure, together with an active semiconductor material that is an electro-optic or electro-absorption material, that are appropriately doped with carriers to substantially lower the modulator voltage and still maintain the high frequency response. In another embodiment, an efficient optical coupling structure further enables low optical loss. Various embodiments combined enable the modulator to reach lower voltage, higher frequency, low optical loss, and more compact size than previously possible in the prior arts.