Wave guide path type liquid crystal light switch

Abstract

The invention provides a waveguide type liquid crystal optical switch that includes first and second cores so as to form a space therebetween, in which an optical path is switched between the first and second cores; a third core provided apart from the first and second cores, into which nematic liquid crystal orientated by an orientation film along a predetermined direction is filled, the third core overlapping to the space formed between the first and second cores; a first electrode arranged on an opposite side of the first and second cores with respect to the third core so as to overlap to the space between the first and second cores, second and third electrodes arranged on both sides of the first electrode, for orienting liquid crystal molecules along a direction perpendicular to the orientation direction of the orientation film; and a cladding for incorporating the cores and the electrodes.

Description

technical field [0001] The invention relates to an optical switch used in an optical communication system, in particular to a waveguide type liquid crystal optical switch which uses liquid crystal to control optical path switching between waveguides. Background technique [0002] Since optical communication can receive and send a large amount of information at high speed, it has become popular in ordinary households in recent years. Optical communication is a transmission system of optical fibers. In order to distribute optical signals to various terminals, fiber-type optical couplers, optical waveguide-type optical splitters, optical splitters, and optical switches have been developed. device. [0003] Among these devices, an optical switch has a function of switching an optical line, and is very important as a switch for optical communication. Various products of optical switches used in optical communication are well known in the past. Among them, optical waveguides are...

AI Technical Summary

Problems solved by technology

[0005] However, in this waveguide type liquid crystal optical switch, the formed liquid crystal and electrodes basically cover the entire lower metal cladding layer, so the refractive index changes in a wide range of the metal cladding layer, and the waveguide method is disturbed. A level of intermodulation distortion considered fatal will occur

Furthermore, since the coupling part of the waveguide core is connected to the liquid crystal on three sides, if there are liquid crystal molecules that are not aligned in the specified direction, the resulting scattering loss will also increase.

In addition, since the lower electrode is very close to the coupling part of the waveguide, the loss of the lower electrode becomes very large.

Furthermore, since the electrodes can only be configured as a pair of upper and lower pairs, there is a problem of strong dependence on polarized waves.

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