Kyoto University

Tdk Corporation

Japan Science and Technology Agency

Sumitomo Electric Industries, Limited

Alps Electric Co., Ltd.

Matsushita Electric Works, Ltd.

Rohm Co., Ltd.

Agency of Industrial Science and Technology

Panasonic Electric Works Co., Ltd.

Osaka Gas Company Limited

Takashi Asano

Susumu Noda

Seiichi Takayama

Yoshinori Tanaka

Hitoshi Kitagawa

Yoshihiro Akahane

Hitomichi Takano

Bong-Shik Song

Ranko Hatsuda

Eiji Miyai

Menaka De Zoysa

Takuya Inoue

Masayuki Fujita

Masahiro Suemitsu

Tadashi Saito

Keisuke Kitano

Anqi Ji

Masamitu Mochizuki

Yasushi Takahashi

Yoshitaka Inui

Masahiro Chihara

Hiroshi Ohata

Keita Mochizuki

Tatsuya Shibahara

Katsuyoshi Suzuki

Kenji Ishizaki

A thermal emission source is provided that has a structure capable of suppressing deterioration of an optical assembly over time. The thermal emission source includes an optical assembly () having an optical structure in which a member made of a semiconductor has a refractive index distribution so as to resonate with light of a wavelength shorter than a wavelength that corresponds to an absorption edge corresponding to a band gap of the semiconductor. The optical assembly () includes a coating structure () with a coating material that differs from the semiconductor of refractive portions () and through which light of a wavelength included in a wavelength range from visible light to far infrared rays can be transmitted.

Thermal emission source

A thermal radiation light source includes a laminated body including m quantum layers laminated where m is an integer of 2 or more, including an n-layer and a p-layer sandwiching the quantum layers from both sides in the laminating direction, the n-layer made of an n-type semiconductor and the p-layer made of a p-type semiconductor; a voltage applying unit for the m quantum layers is directly or indirectly connected to the n-layer and p-layer sandwiching each layer applying a voltage for moving to the n-layers or p-layers a charge; a voltage switching unit switches ON/OFF of application of the voltage to the m quantum layers; and a photonic crystal portion disposed in the laminated body or adjacent to the laminated body, so that lights of m wavelengths resonate, the lights of the m wavelengths generated in the m quantum layers corresponding to transition energy between subbands in the quantum layer.

Thermal radiation light source

A thermal emission source capable of switching the intensity of light at a high response speed similarly to a photoelectric conversion element. A thermal emission source includes: a two-dimensional photonic crystal including a slab in which an n-layer made of an n-type semiconductor, a quantum well structure layer having a quantum well structure, and a p-layer made of a p-type semiconductor are stacked in the mentioned order in the thickness direction, wherein modified refractive index areas (air holes) whose refractive index differs from the refractive indices of the n-layer, the p-layer and the quantum well structure layer are cyclically arranged in the slab so as to resonate with a specific wavelength of light corresponding to a transition energy between the subbands in a quantum well in the quantum well structure layer; and a p-type electrode and an n-type electrode for applying, to the slab, a voltage which is negative on the side of the p-layer and positive on the side of the n-layer.

Thermal emission source and two-dimensional photonic crystal for use in the same emission source

A Raman scattered light enhancement device including a waveguide provided in a photonic crystal () made of a semiconductor substrate in which holes () are formed. The waveguide has resonant modes with respect to incident light at a plurality of frequencies. A difference in frequency between one resonant mode and another resonant mode is equal to a Raman shift frequency of the semiconductor substrate. A waveguide forming direction with respect to a crystal plane orientation of the semiconductor substrate is set so as to maximize a Raman transition probability which is represented by electromagnetic field distribution of the two resonant modes and a Raman tensor of the semiconductor substrate.

Raman scattering photoenhancement device, method for manufacturing Raman scattering photoenhancement device, and Raman laser light source using Raman scattering photoenhancement device

In conventional organic EL light-emitting devices, the ITO used for a transparent electrode has a refractive index of about 2.0 larger than the refractive index of 1.5 of a transparent glass substrate. As a result, the mode of most of light traveling from the transparent electrode toward the glass substrate is the transparent electrode guided mode, and no light is emitted from the transparent electrode toward the glass substrate. According to the invention, the light extraction efficiency of conventional light-emitting devices such as organic EL light-emitting devices is improved by using mode conversion means so as to solve the problem that conventional light-emitting devices such as organic EL light-emitting devices have low light extraction efficiencies. A light-emitting device of the invention comprises a light-emitting layer on a substrate and mode conversion means for converting the mode from the guided mode into an emission mode. The mode conversion means is provided in the substrate, in the light-emitting layer, or at the interface between the substrate and the light-emitting layer.

Light-emitting device and organic electroluminescence light-emitting device

Holesare created in a slab-shaped body. On the first surfaceof the body, the holesare arranged at the lattice points of a triangular lattice. On the second surface, they are arranged at the lattice pointslocated at positions corresponding to the gravity center of a triangular lattice. Three air columnsA obliquely extend from each lattice pointto the nearest three lattice points. Similarly, three air columnsA obliquely extend from each lattice pointto the nearest three lattice points. In this construction, a periodic structural unitconsisting of three holes is created within the bodyand this unit has a C-symmetrical shape at any sectionparallel to the body. Due to this symmetry and the obliquely extending form of the air columnA, a complete PBG with a large width is obtained. In one embodiment, a broad complete PBG whose width equals 15% of its middle value is obtained.

Two-dimensional photonic crystal

A two-dimensional photonic crystal according to the present invention includes a first layer having a dielectric first layer slab in which first layer holes having a refractive index lower than that of the first layer slab are arranged cyclically, a second layer formed on the first layer, including dielectric columns having a refractive index higher than the air arranged in the air with the same cycle as the first layer hole, and a third layer having a dielectric third layer slab in which third layer holes having a refractive index lower than that of the third layer slab are arranged cyclically. Thus, it is possible to obtain the two-dimensional photonic crystal that can create a wider complete PBG than before regardless of the polarization of light and can be manufactured easily.

A highly sensitive and compactable target substance sensor for detection of the target substance using a photonic crystal and a method thereof. The sensor includes an electromagnetic wave source of supplying an electromagnetic wave, a photonic sensor element, and a detector. The photonic sensor element has photonic crystalline structure and is configured to include a sensor waveguide for introducing the electromagnetic wave, and a sensing resonator electromagnetically coupled to the sensor waveguide for resonating the electromagnetic wave at specific wavelength. The sensing resonator is exposed to an atmosphere including the target substance so as to vary a characteristic of the electromagnetic wave emitted from the sensing resonator. The detector is configured to receive the electromagnetic wave emitted from the sensing resonator to recognize an intensity variation of the electromagnetic wave and issue a signal indicative of a characteristic of the target substance.

Target substance sensor and method thereof using a photonic crystal

The present invention intends to provide a two-dimensional photonic crystal resonator having a high Q-value. The slab-shaped bodyis provided with cyclically arranged holes. The bodyis divided into three areas-with the holesarranged with cycle distances of ain areaand ain areasand, which is smaller than a. A waveguidepassing through the three areas is formed by linearly eliminating the holes. The waveguidethus formed can propagate rays of light within a wavelength band that depends on the cycle distance of the holes. The cycle distance of the holes in the areadiffers from that of the areasand, and the wavelength band of the light propagating through the waveguide accordingly differs. Therefore, a ray of light whose wavelength is within the waveguide transmission wavelength band of the areabut outside of the waveguide transmission wavelength band of the other areasandwill be confined within the waveguide of the areaand resonate therein. Thus, the waveguide in the areafunctions as a resonator.

Two-dimensional photonic crystal resonator

An object of the present invention is to provide a two-dimensional photonic crystal in which conditions for both the TE-polarized light and the TM-polarized light can be easily satisfied. A body includes a first area having a triangular lattice pattern arrangement of a circular hole and a second area having a triangular lattice pattern arrangement of an equilateral triangular holes. Therefore, the TE-PBG which is a photonic band gap (PBG) for the TE-polarized light is created in the first area, and the TM-PBG which is a PBG for the TM-polarized light is created in the second area. Parameters such as the period and size of the holes can be independently set for the first area and the second area, so that an energy region common to the TE-PBG and the TM-PBG (i.e. absolute PBG) can be made larger and easily created. Forming a waveguide and resonators and or the like corresponding to an energy within the absolute PBG allows formation of a polarized light multiplexer/demultiplexer and a frequency (wavelength) multiplexer/demultiplexer without depending on polarized light or the like.

Two-dimensional photonic crystal and optical device using the same

The present invention provides a two-dimensional photonic crystal in which an absolute photonic band gap (PBG), i.e. a photonic band gap that is effective for both the TE-polarized light and the TM-polarized light within a predetermined wavelength range, is created with an adequate bandwidth. The bodyis provided with holesarranged in a triangular lattice pattern, where the basic shape of the hole is an equilateral triangle. This shaping and arranging of the holes creates an absolute PBG. Each corner of the equilateral triangle is cut along an arc to leave an adequate distance between the neighboring holes (i.e. an adequate width of the connecting portion of the body). This design makes it possible to enlarge each holewhile ensuring an adequate strength of the two-dimensional photonic crystal. This construction creates an absolute PBG having a large width.

The present invention provides a polarized light mode converter which can be provided within a two-dimensional photonic crystal or can be smoothly connected to a two-dimensional photonic crystal. In a two-dimensional photonic crystal made of a slab-like main body provided with a plurality of different refractive index regions (for example, holes) arranged in a lattice in the main body, where the different refractive index regions have a refractive index different from that of the main body, a polarized light conversion waveguideis formed which is comprised of defects of the different refractive index regions arranged linearly whose a cross-sectional shape is asymmetrical in a vertical and in a horizontal direction. The polarized light conversion waveguidecan be, for example, realized by providing, on a side of the waveguide, holesandextending in a direction oblique to a the main body surface. TE polarized light propagating through the polarized light conversion waveguideis partially converted into TM polarized light due to the asymmetry of the cross-sectional shape of the waveguide. Since the polarized light mode converter is made of a two-dimensional photonic crystal, it can be provided within a two-dimensional photonic crystal or can be smoothly connected to a two-dimensional photonic crystal.

Polarized light mode converter

The present invention has been made for providing a photonic crystal capable of multiplexing or demultiplexing light within a wavelength band having a certain width. It includes a slab-shaped bodyprovided with plural forbidden band zonesandand holesandhaving different sizes are arranged in the forbidden band zones with different cycles, respectively. Also formed are a trunk waveguideextending along the direction inclined by +30 degrees from a perpendicular of the boundarybetween the forbidden band zonesandand a branch waveguideextending along the direction inclined by &#x2212;30 degrees. A ray of light within the multiplexed/demultiplexed wavelength band, which is excluded from the transmission wavelength band of the trunk waveguidein the forbidden band zoneand included in the transmission wavelength band of the trunk waveguidein the forbidden band zoneis reflected by the boundaryand thereby demultiplexed from the trunk waveguideinto the branch waveguide. Thus, all the rays of light whose wavelengths are within the multiplexed/demultiplexed wavelength band having a certain width are demultiplexed into the branch waveguide. Therefore, even if the wavelength of the optical signal is deviated due to some error, the light can be demultiplexed. This is also true for the multiplexing operation.

Photonic crystal having heterostructure and optical device using the photonic crystal

The present invention is aimed at providing a two-dimensional photonic crystal wavelength multiplexer/demultiplexer capable of multiplexing and demultiplexing both TE and TM-polarized lights. In the wavelength multiplexer/demultiplexer, first and second resonators having the same resonance wavelength &#x3bb;r are provided between first and second waveguides and which are separately provided in a two-dimensional photonic crystal having a photonic band gap for the TE polarization. A first polarization converter for converting a TM-polarized light to a TE-polarized light is provided on the first waveguidebetween the first and second resonators and. Similarly, a second polarization converter for converting a TE-polarized light to a TM-polarized light is provided on the second waveguide between the first and second resonators and. Among the light propagating through the first waveguide, the TE-polarized light with wavelength &#x3bb;r is introduced from the first resonator into the second waveguide, whereas the TM-polarized light is converted to a TE-polarized light by the first polarization converter and then introduced through the second resonator into the second waveguide.

Polarization-independent two-dimensional photonic crystal multiplexer/demultiplexer

The present invention intends to provide a two-dimensional photonic crystal having a wide photonic band gap (PBG). In a slab-shaped body, a number of holes, whose sectional shape on a plane parallel to the slab surface is an equilateral triangle, are periodically arranged in a triangular lattice pattern. The upper and lower sides of the holesare covered with the material of the body. The aforementioned sectional shape is uneven along the direction perpendicular to the slab surface. This construction expands the PBG for TM-polarized light and thereby increases its energy region overlapping with the PBG for TE-polarized light. This overlapping section is the complete PBG. If a ray of light whose wavelength corresponds to an energy level within the complete PBG, neither the TE-polarized nor TM-polarized component of the light can be propagated through the photonic crystal. Therefore, even if a waveguide and/or a resonator is provided in the photonic crystal, the light having the aforementioned wavelength will never leak from the waveguide or resonator into the photonic crystal.

Growing community of inventors

Kyoto, Japan

Takashi Asano