Abstract:
Disclosed in a method and a device in which a wave number of light in the waveguide mode of a photonic crystal optical waveguide is matched with that of the incident light, or a intensity ratio of electric field to magnetic field of the light in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light, and furthermore, in addition to the method above, the distribution of light intensity on the incident end surface in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light. A photonic crystal optical waveguide and channel optical waveguide are joined together, and the structure of the channel optical waveguide is wedge shaped in the joint section.
Abstract:
In an optical circuit including multi-dimensional photonic crystals, in which the optical circuit has a structure (33), such as a light emitting member or a light receiving member, having a natural resonance frequency, another structure (34) having a natural resonance frequency slightly differing from the natural resonance frequency of the structure (33) is arranged in the vicinity of the structure (33) to control the directivity of localization and propagation of an electromagnetic field, light emission and light reception in a spatial region including the above structures in the multi-dimensional photonic crystals, in order to permit functional operations to be realized.
Abstract:
To provide an optical modulator having a reduced size and reduced power consumption and capable of being easily connected to a waveguide and a method of manufacturing the optical modulator. The optical modulator has at least semiconductor layer (8) having a rib-shaped portion and doped so as to be of a first conduction type, dielectric layer (11) laid on first-conduction-type semiconductor layer (8), and semiconductor layer (9) laid on dielectric layer (11), having the width at the side opposite from dielectric layer (11) increased relative to the width of the rib-shaped portion, and doped so as to be of a second conduction type.
Abstract:
The present invention provides a small optical waveguide structure capable of converting the spot size of light, and capable of reducing the conversion loss when compared under the condition of the same waveguide length and performing an optical conversion with high efficiency. An optical waveguide structure (100) includes a base waveguide (110) including a taper section (111) whose width becomes continuously narrower from one side toward another side, and a narrow-width section (112) that is consecutively connected to a narrow-width side of the taper section (111) and extends toward the another side. In the optical waveguide structure (100), at least three-layered upper waveguides (121 to 123) each of which has a planar shape smaller than the taper section (111) and includes a planar-view-roughly-wedge-shaped section whose width becomes continuously narrower from the one side toward the another side at least on a tip side are stacked above the taper section (111) of the base waveguide (110) in such a manner that the planar shape becomes successively smaller from the base waveguide side (110).
Abstract:
A semiconductor device comprises a semiconductor layer having a semiconductor integrated circuit, which is for processing an electrical signal, on a semiconductor substrate and an optical interconnect layer for transmitting an optical signal are joined. Control of modulation of the optical signal transmitted in the optical interconnect layer is performed by an electrical signal from the semiconductor layer, and an electrical signal generated by reception of light in the optical interconnect layer is transmitted to the semiconductor layer. The optical interconnect layer is disposed on the underside of the semiconductor substrate.
Abstract:
A downsized, low-power electro-optical modulator that achieves reducing both of the additional resistance in the modulation portion and the optical loss each caused by electrodes at the same time is provided. The electro-optical modulator includes a rib waveguide formed by stacking a second semiconductor layer 9 having a different conductivity type from a first semiconductor layer 8 on the first semiconductor layer 8 via a dielectric film 11, and the semiconductor layers 8 and 9 are connectable to an external terminal via highly-doped portions 4 and 10, respectively. In a region in the vicinity of contact surfaces of the semiconductor layers 8 and 9 with the dielectric film 11, a free carrier is accumulated, removed, or inverted by an electrical signal from the external terminal, and whereby a concentration of the free carrier in an electric field region of an optical signal is modulated, so that a phase of the optical signal can be modulated. At least one of the semiconductor layers 8 and 9 is wider than the stacked portion. At least one of the highly-doped portions 4 and 10 is formed outside the stacked portion.
Abstract:
The lattice mismatching between a Ge layer and a Si layer is as large as about 4%. Thus, when the Ge layer is grown on the Si layer, penetration dislocation is introduced to cause leakage current at the p-i-n junction. Thereby, the photo-detection sensitivity is reduced, and the reliability of the element is also lowered. Further, in the connection with a Si waveguide, there are also problems of the reflection loss due to the difference in refractive index between Si and Ge, and of the absorption loss caused by a metal electrode. In order to solve said problems, according to the present invention, there is provided a vertical type pin-SiGe photodiode having a structure which is embedded in a groove formed in a part of a Si layer, in which a p-type or n-type doped layer is formed in a lower section of the groove, and in which a i-SiGe layer having a rectangular shape or a reverse tapered shape is formed on a layered structure formed by laminating a i-Si layer and a SiGe buffer layer on the lower section and the side wall of the groove. Further, in an optical connection section with a Si waveguide, impedance matching is effected by the layered structure composed of the i-Si layer and the SiGe buffer layer, and an upper metal layer is separated therefrom so that a poly-Si bridge structure is employed to electrically connect the upper metal layer therewith.
Abstract:
In an optical circuit including multi-dimensional photonic crystals, in which the optical circuit has a structure (33), such as a light emitting member or a light receiving member, having a natural resonance frequency, another structure (34) having a natural resonance frequency slightly differing from the natural resonance frequency of the structure (33) is arranged in the vicinity of the structure (33) to control the directivity of localization and propagation of an electromagnetic field, light emission and light reception in a spatial region including the above structures in the multi-dimensional photonic crystals, in order to permit functional operations to be realized.
Abstract:
Disclosed in a method and a device in which a wave number of light in the waveguide mode of a photonic crystal optical waveguide is matched with that of the incident light, or a intensity ratio of electric field to magnetic field of the light in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light, and furthermore, in addition to the method above, the distribution of light intensity on the incident end surface in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light. A photonic crystal optical waveguide and channel optical waveguide are joined together, and the structure of the channel optical waveguide is wedge shaped in the joint section.
Abstract:
An optical waveguide type optical terminator forms an optical waveguide structure including at least an optical absorption core (103) which is formed on a clad layer (102) and includes a portion composed of silicon in which an impurity of 1019 cm−3 or more is doped, and is used by being optically connected in series with an optical waveguide including a core (105) composed of silicon. The optical absorption core (103) is sufficient provided that, at least, an impurity of around 1019 cm−3 is doped therein. For example, its impurity concentration is sufficient provided that it falls within a range of 1019 -1020 cm−3. The existence of this impurity causes absorption of light in the optical absorption core (103).