Mitsubishi Gas Chemical Company, Inc.

Hisashi Ohwada

Kuniaki Jinnai

Yasunari Kawabata

Toshihiko Takano

Norio Takeda

Mitsuzo Arii

Michio Ohba

Osamu Kondoh

Tomoko Kondoh

Shigeo Kataoka

Hamaho Hashimoto

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&times;N optical couplers (2&lE;N&lE;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&times;N optical couplers.

Wavelength division multiplexing device

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).

Optical waveguide module having main-line waveguide and branch

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.

Method for manufacturing optical element

The present invention is an optical device including an optical circuit in which a plurality of branched optical waveguides are connected to a light receiving side and a light ejecting side of a main optical waveguide which mixes the entering light. The branched optical waveguides include a beginning and a terminal end. The terminal end is connected to an optical fiber and the beginning end is connected to the main optical waveguide. At least one of the branched optical waveguides has a slope or taper construction which is wider at the terminal end than at the beginning end, in order to improve lost variance and to reduce loss of light signals. The present invention also provides a method for manufacturing the above-described optical device to be used in optical local networks and optical instrumentation control systems.

Design and manufacture of an optimized waveguide-type multiple branched

An optical divider for multimode optical fibers of graded-index (GI) type composed of an optical input section for securing input optical fiber, a branching section including an optical waveguide having rectangular sectional shapes irrespective of a kind of material or a method of fabricating the same and consists of a main optical waveguide and branch waveguide, and an optical output section for securing an array of output optical fibers, wherein the main optical waveguide having a width D and a length M is divided contiguously into N branch optical waveguides, preferably three or more having uniform width W, the optical waveguide having substantially uniform core thickness T is specifically related with the core diameter K of the otpical fiber to fufull the following relational formulas:

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Tokyo, Japan

Hisashi Ohwada