摘要:
A metal surface plasmon is excited in a multi-layered film composed of thin metal films and a thin dielectric film, by light having a propagation constant larger than that of the incident light emitted from an optical component such as a prism. Due to an extremely strong alternating electric field produced by the electric field enhancement effect of the metal surface plasmon, a harmonic is generated from a nonlinear optical crystal.
摘要:
A small-sized and low-cost wavelength division multiplexer having little insertion loss, little polarization dependence and a broad wavelength bandwidth, the wavelength division multiplexer adopting a grating configuration in which an incident light is retroreflected, exit lights from respective grooves are enhanced by interference effect in the incident direction of the light, wave surfaces of evanescent waves in the grooves are parallel to the normal direction of the grating and phases of the evanescent waves in the respective grooves agree with each other. The wavelength division multiplexer has high diffraction efficiency in each of TM and TE polarized lights at a several-order diffraction order and accordingly has a broad wavelength bandwidth and remarkably low polarization dependence.
摘要:
An optical harmonic generator for obtaining a harmonic with a wavelength which is an integral measure of the wavelength of incident light by the use of a nonlinear optical effect is provided which is used, for example, to obtain a laser beam having a shorter wavelength. The optical harmonic generator is formed by laminating a dielectric, a metal thin film, and a nonlinear thin film waveguide. A very strong alternating electric field, produced by the electric field enhancement effect of a metal surface plasmon excited by the metal thin film, is applied near the interface between the nonlinear thin film waveguide and the metal thin film, and a harmonic is generated from the nonlinear thin film waveguide by the alternating electric field. By selecting the film thickness of the metal thin film and the depth of the nonlinear thin film waveguide, phase matching between the incident light and the generated harmonic is achieved.
摘要:
A reversible temperature indicating material which is chemically stable, is not harmful and can be produced relatively inexpensively contains as principal component a polycrystalline bismuth-chromium oxide substance produced by firing a mixture with 50-86 molar % of bismuth-containing compounds and 50-14 molar % of chromium-containing compounds.
摘要:
An object of the present invention is to allow an optical element to be obtained with good precision using a polymer film and a glass substrate as a reinforcer. The present invention is characterized by the fact that a polymer film is formed on a glass substrate which has been treated to prevent the glass substrate and polymer from separation. This allows an optical circuit pattern to be formed without producing separation between the glass substrate and polymer film when the film is formed. The dimensional precision of the configuration of the distributed index in the polymer film can be maintained generally to the same extent as the expansion and shrinkage of the glass substrate. In addition, a vessel obtained with a glass substrate as the bottom surface can be used as the casting vessel.
摘要:
An optical isolator comprises two birefringent plates one of which separates two light components whose planes of polarization are perpendicular to each other to make the two light components spatially separate between the two birefringent plates and pass through two separate optical paths and the other of which thereafter combines the two separate light components, two Faraday rotators disposed between the two birefringent plates and having a Faraday rotation angle of approximately 45 degrees, a polarizer disposed between the two Faraday rotators and having a predetermined polarized-light transmitting angle, and a magnetic field device for applying an external magnetic field to the two separate optical paths in the two Faraday rotators to magnetize respective regions near the two optical paths in each of the rotators in opposite magnetization directions to each other. In this arrangement two light components entering the polarizer in the forward direction has the same angle of plane of polarization as the predetermined polarized-light transmitting angle of the polarizer so as to pass through the polarizer, but two light components entering the polarizer in the reverse direction has an angle of plane of polarization perpendicular to the predetermined polarized-light transmitting angle of the polarizer so as not to pass through the polarizer. The high performance polarization-independent optical isolator may be obtained with high isolation of more than 50 dB, which is easy in assembling or manufacturing.
摘要:
A wavelength division multiplexing device which can easily utilize existing optical fibers for increasing the transmission capacity by approximately several fold mainly in a short-range information communication network, comprising, as essential elements, a pair of 1×N optical couplers (2≦N≦16), N light emission devices in which one of peak wavelengths thereof differs from every other one by at least 30 nm and N light receivers having optical filters having light-transmission wavelength bands adjusted to correspond to said peak wavelengths, wherein the light emission devices and the light receivers having optical filters corresponding to peak wavelengths of the light emission devices form pairs, and said light emission devices of said light receivers are optically connected to N-port-side ports of one of the 1×N optical couplers.
摘要:
An optical waveguide module having a main-line waveguide, which is excellent in optical branching properties, important properties of a bus communication network, and the reproducibility of the above branching properties and is easy to produce, and an optical transmission equipment having the above optical waveguide module. The optical waveguide module having a main-line waveguide which is connected to the optical transmission path and works as part of the optical transmission path and a pair of branch waveguides (21,22) which are unidirectionally branched from the main-line waveguide, the main-line waveguide and the branch waveguides being formed by providing an optically transparent polymer film with a refractive index distribution, a light-receiving device (25) being connected to one (21) of a pair of the branch waveguides, a light-emitting device (26) being connected to the other (22).