Abstract:
An object of this invention is to cancel a polarization dependence of a transmission center wavelength due to the waveguide birefringence in an array waveguide and a slab waveguide in an array waveguide diffraction grating type optical multiplexer/demultiplexer filter applied for optical communication, particularly, wavelength split multiplexing system. In order to achieve the object of this invention, a polarization mode convertor converts the TE mode in a waveguide to the TM mode and the TM mode to the TE mode. This conversion function makes it possible to cancel the polarization dependence of the transmission center wavelength due to the waveguide birefringence in the array waveguide and the slab waveguide in front of and behind the polarization mode convertor.
Abstract:
An optical waveguide circuit device strong in impact strength in dropping, etc. is provided. A waveguide pattern is formed on a silicon substrate in this optical waveguide circuit device. For example, this waveguide pattern has an optical input waveguide, a first slab waveguide, an arrayed waveguide including a plurality of channel waveguides having lengths different from each other and arranged side by side, a second slab waveguide, and a plurality of optical output waveguides arranged side by side. The first slab waveguide is separated on a cross separating face crossing an optical path passing the first slab waveguide. A temperature dependence in light transmission central wavelength of an arrayed waveguide grating is reduced by sliding and moving a separating slab waveguide side by a slide moving member along the separating face depending on temperature. The cross separating face and a noncross separating face communicated with this cross separating face are set to faces not conformed to a cleavage plane of the substrate.
Abstract:
A single free-beam region for coupling electromagnetic radiation in and out is provided in order in the case of an AWG coupler for spectrally separating electromagnetic radiation to achieve a more stable thermal characteristic and a space-saving layout.
Abstract:
A process for forming an integrated optical device in a glass substrate, comprising the steps of: providing a glass substrate having a base index of refraction; providing a UV light beam; focusing the beam on a portion of the glass substrate in order to form a region of increased refraction; and scanning an elongated region of the glass substrate with the beam in order to define at least one elongated optical channel having an increased index of refraction relative to the base index of refraction, the elongated optical cannel for guiding light transmitted there along. The process further includes: forming a plurality of elongated optical channels in said glass substrate, wherein a first optical channel is operative for transmitting light to said plurality of elongated optical channels such that said transmitted light is divided among said plurality of elongated optical channels, thereby forming an optical beamsplitter.
Abstract:
The invention provides a simple metallic film manufacturing method for manufacturing an arrayed waveguide grating able to set each light transmitting central wavelength to a set wavelength at optionally predetermined temperature (for example 25° C.). The arrayed waveguide grating is manufactured by using this method. The light transmitting central wavelength of a circuit forming a waveguide forming area on a substrate is measured, and a shift of the light transmitting central wavelength from the set wavelength is corrected by annealing process. A mask has a hole approximately formed in the same shape as the manufactured metallic film, and is arranged such that the hole of the mask corresponds to a manufacturing portion of the metallic film. The metallic film is manufactured by evaporation, etc. A intersecting planes is formed by primary cutting, and a position shifting member is fixed through the metallic film and solder, and a non-intersecting planes is formed by secondary cutting so that the waveguide forming area is cut and separated.
Abstract:
An optical multiplexer/demultiplexer that the passband characteristic of demultiplexed optical signal in a waveguide on the output side can be controlled accurately. Long and narrow guide waveguides, being areas where an effective refractive index is greater than an effective refractive index of a sector slab waveguide on the input side, are formed in the core or in an area adjacent to the core so that the long and narrow guide waveguides will branch at the center of curvature of the sector slab waveguide and so that the long and narrow guide waveguides will extend in an output direction without intersecting with one another. When optical signal is input to the sector slab waveguide, the light is guided more strongly through areas where the guide waveguides are formed. As a result, with the propagation of the optical signal, a peak corresponding to the shape of the guide waveguides will appear in the shape of a mode of the optical signal. Therefore, the shape of a mode of optical signal which propagates can be controlled accurately according to a passband characteristic needed in an optical output waveguide.
Abstract:
An optical system includes a delay region having a photonic band structure, a modulated optical signal source, an optical input, and an optical output. The optical input couples modulated input optical signals into a predetermined mode in the delay region such that group velocity of the optical signal is reduced. The optical output includes a wavelength selective element. Input optical signals are coupled into a highly dispersive mode in the delay region in which the group velocity of the optical signal is reduced. The input signal, which has been delayed and dispersed, is recovered at the output of the device using the wavelength selective element.
Abstract:
An optical device includes a waveguide bounded by a region containing a photonic band gap the properties of which determined the transfer characteristic of the waveguide. Such a device may serve as a component of, for example a wavelength division multiplexer, a monochromatic laser or a chemical sensor. It may serve as an optical bus for an electronic component such as a microprocessor. These devices are particularly suitable for incorporation in optical and opto-electronic integrated circuits as they permit the fabrication of waveguides having right-angle bends with a radius of the order of 2 &mgr;m.
Abstract:
A dual wavelength-division multiplexing/demultiplexing device for multiplexing/demultiplexing optical signals is provided. The device comprising (a) a planar-light guide circuit comprising a first wavelength-division multiplexing/demultiplexing device and a second wavelength-division multiplexing/demultiplexing device, the first wavelength-division multiplexing/demultiplexing device having input and output ports of several first input and output waveguides at one side and a first arrayed-waveguide grating coupled to the several first input and output waveguides, and the second wavelength-division multiplexing/demultiplexing device positioned in symmetry with the first wavelength-division multiplexing/demultiplexing device along the center and comprising the input and output ports of several second input and output waveguides at the opposite side and a second arrayed-waveguide grating coupled to the several second input and output waveguides; (b) a first optical-fiber array block having a number of ports corresponding to the input and output ports of the several first input and output waveguides and connected to first ribbon optical fibers; and, (c) a second optical-fiber array block having a number of ports corresponding to the input and output ports of the several second input and output waveguides and connected to second ribbon optical fibers.
Abstract:
The invention relates to an athermal arrayed waveguide grating, comprising: a) an input slab waveguide being connected to at least one input waveguide, b) an output slab waveguide being connected to at least one output waveguide, and c) a plurality of arrayed waveguides that i) are arranged between the input slab waveguide and the output slab waveguide and ii) are made of a first material whose refractive index has a first type of temperature dependence. According to the invention, the input slab waveguide comprises one single part that is completely made of a second material having a refractive index with a second type of temperature dependence that is opposite to the first type of temperature dependence.