Component for light isolator, its mfg. method and light isolator using such component for light isolator

Abstract

An optical isolator (1) is constructed such that an optical isolator element (5) in which at least one flat Faraday rotator (2) and at least two flat polarizers (3,4) are bonded to each other into an integral unit by van der Waals forces or hydrogen-bonding forces acting between bonding surfaces of the Faraday rotator (2) and the polarizers (3,4) is accommodated in a tubular magnetic element (6).

Description

technical field [0001] The present invention relates to an optical isolator element used to remove return light generated when light emitted from a light source is introduced into various optical elements or optical fibers, a manufacturing method thereof, and an optical isolator using the optical isolator element. Background technique [0002] In an optical communication module, etc., light emitted from a light source such as a laser light source is incident on various optical elements or optical fibers, but a part of the incident light is reflected or scattered on the end surface or inside of various optical elements or optical fibers. . Part of the reflected or scattered light is returned to the light source as return light as it is. Therefore, an optical isolator is used to prevent the return light from returning to the light source. [0003] Conventionally, such an optical isolator is constructed by disposing a flat-plate Faraday rotator between two polarizers, and acc...

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Problems solved by technology

Furthermore, the gas emitted from the organic adhesive 19 adheres to the surface of optical components such as laser chips or lenses, and there is a risk of deteriorating optical properties.

[0016] In addition, in the optical isolator element 20 in which the plate-shaped polarizers 17 and 18 are bonded on both sides of the Faraday rotator 16 with low-melting-point glass 19, the glass transition temperature of the low-melting-point glass 19 is as high as several hundred degrees. Therefore, after melting and fixing each member, thermal stress increases when cooling to room temperature, and there is a risk of cracks occurring in each member or the low-melting glass 19

In addition, if thermal stress is applied to the Faraday rotator 16, the extinction ratio of the light passing through the Faraday rotator 16 deteriorates, and various characteristics of the optical isolator 15, especially the reverse direction attenuation characteristics deteriorate.

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