Home | Links | Contact Us | More About Intellectual Property | Bookmark

Search patents:

Home

I/O Systems

Fiber-optic-polarization-controller

Protective device for overhead wires containing optical fiber units

What are claimed are: 1. Structure for connecting overhead earth wires containing an optical fiber ...

Data processing system having interlinked slow and fast memory means

In accordance with the present invention, there is provided a data processing system having a large ...

Semiconductor memory having subarrays and partial word lines

I claim: 1. A semiconductor array memory comprising a plurality of selectable subarrays arranged on ...

Flat-cell read-only-memory integrated circuit

OF THE PREFERRED EMBODIMENT A detailed description of the preferred embodiments of the present ...

Variable sized FIFO memory and programmable trigger level therefor for use in a UART or the like

In accordance with the illustrated embodiments, the present invention provides a data available ...

Apparatus for programmable circuit and signal switching

We claim: 1. A programmable interconnect device for routing signals between signal ports in ...

Semiconductor memory device having hierarchical bit line structure employing improved bit line precharging system

Accordingly, a first object of the present invention is to provide a semiconductor memory device of ...

Dram core refresh with reduced spike current

The present invention makes multibank refresh more practical by varying the current profile for the ...

Shape memory alloy optical fiber switch

In FIG. 1, a switch is shown as a double pole switch. That is, two sets of fibers are switched and ...

Semiconductor memory device with reduced inter-band tunnel current

Accordingly, it is a general object of the present invention to provide a semiconductor memory ...

Fiber optic polarization controller

Details

Inventors: Matsumoto, Takao; Kano, Haruo;
Assignee: Nippon Telegraph and Telephone Corporation (Tokyo, JP)
Primary Examiner: Sikes; William L.
Assistant Examiner: Ullah; Akm E.
Attorney, Agent or Firm: Cushman, Darby & Cushman

This invention relates to a fiber optic polarization controller which controls the polarization direction of the light propagating through an optical fiber by curving a single-mode fiber within an imaginary plane S to generate birefringence on the fiber and by rotating the plane S defined with the thus curved portion. The invention aims to prevent twists of the optical fiber which are caused in rotating the plane S by rotating the fiber in one direction from the plane S simultaneously with the rotation of the plane S and correspondingly to the angle thereof. The optical fiber may be rotated either by utilizing the stability of fiber which is held loosely at a curved portion or by forcibly rotating the curved portion from outside.

DETAILED DESCRIPTION An object of this invention is to provide a fiber optic polarization controller which can rotate polarization direction endlessly so as to enable continuous follow-up of all the changes in polarization.
Ancther object of this invention is to provide a device which does not cause twists on optical fibers even if the polarization angle of a single-mode optical fiber is mechanically rotated.
The fiber optic polarization controller according to this invention comprises a curved portion for generating birefringence within a fiber and uses the rotation of a plane S defined with the curved portion just like the prior art fiber optic polarization controllers.
The principal of this invention lies in that a single-mode fiber is curved along an imaginary plane S, polarization is controlled with rotation of the plane, and the optical fiber is rotated around the axis of the fiber at the same time.
While the optical fiber is fixed in relation to the plane in conventional controllers, the optical fiber according to this invention is rotated in a adequate direction by an angle identical and the opposite direction with the angle of the rotation of said plane S.
Due to such features of the invention, even if said plane S is rotated in one direction by a large angle, no distortion occurs on the fiber thereby preventing cutting-offs by fatigue.
If the curvature of the optical fiber is constructed to allow fine adjustments, the birefringence can be adjusted by an extremely simple operation to provide a desired polarization state.
This can relax the manufacturing precision of fiber optic polarization controllers.

Related patents

	Communication apparatus operative to switch dynamically between different communication configurations by indexing each set of configurables with a unique memory address In accordance with the present invention, communication apparatus is operative to switch communication dynamically between itself and a selected one of a predetermined ...
	Universal host interface for data acquisition systems In accordance with these and other objects, provided is a universal interface system for use with a data acquisition system including a data acquisition device for ...
	Method and system for extracting control information from packetized data received by a communications interface device In light of the above-stated limitations, there is a need for a method and system that integrates zoom video port output from a PCI-interface device that permits ...
	Information processing system OF EMBODIMENTS Several examples of preferred embodiments of the present invention will be explained in details with reference to the drawings in the followings. FIG. 2 ...
	Apparatus and method for the handling of banded frame buffer overflows OF THE DISCLOSURE Referring first to FIG. 1, a top level block diagram of a laser printer 10 is depicted. Laser printer 10 includes a print engine 12, an engine ...
	Method and system for the extensibility of objects In accordance with the present invention, a method and system are disclosed for an extensible object data structure for use by computing machines. The data structure ...
	Information packet reception indicator for reducing the utilization of a host system processor unit The present invention enables a reception related interrupt to be issued by a network peripheral at a time that reduces the utilization of a host system's processor unit ...
	12C bus expansion apparatus and method therefor The aforementioned needs are addressed by the present invention. Accordingly, there is provided in a first form, an apparatus for inter-IC (I.sup.2 C) bus expansion. The ...
	Optical transmission systems What I claim as my invention is: 1. For use in an optical transmission system, an optical fibre connector comprising two separately formed bodies, one body of the ...
	Method and apparatus for repairing fiber optic cable Fiber optic cable is being used more and more in today's telecommunications systems. One of the many reasons for this is that optical fibers are small, when compared to ...

0.014
Archive: All patents - Links Copyright (c)2006 Eipa-patents.org - All rights reserved