Faraday rotator and optical isolator based on this faraday rotator

Patent metadata

Field	Value
Publication number	US-10168556-B2
Application number	US-201615354552-A
Country	US
Kind code	B2
Filing date	Nov 17, 2016
Priority date	Apr 1, 2013
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

To provide a faraday rotator using a TGG ceramic sintered compact and a light isolator using the faraday rotator such that the influence of scattered light can be relatively reduced and overall characteristics degradation for the entire light isolator is minimized so that a high extinction ratio of at least 38 dB or greater is achieved.
[Solution] The faraday rotator according to the present invention uses a TGG ceramic sintered compact having an average particle diameter of 0.2 to 5.0 μm, and has a transmission beam diameter of 0.3 mm or more, the TGG ceramic sintered compact being preferably annealed.

First claim

The invention claimed is:

1. A method of making a Faraday rotator, the method comprising:
providing a ceramics sintered compact represented by Tb 3 Ga 5 O 12 having a mean grain diameter of 0.2-5.0 micrometers;
polishing or grinding the ceramics sintered compact; and
annealing the ceramics sintered compact at a temperature in a range of 1400-1700° C. after the polishing or grinding of the ceramics sintered compact
wherein the Faraday rotator has an extinction ratio of 38 dB or higher with respect to a transmitted light beam of a wavelength of 1064 nm and a beam diameter of 0.3 mm or greater.

2. The method of making a Faraday rotator according to claim 1 , wherein the mean grain diameter is in a range of 0.3-3.0 micrometers.

3. A method of making an optical isolator comprising the method of making a Faraday rotator according to claim 1 .

Assignees

• Shinetsu Chemical Co

Inventors

• Watanabe Toshiaki

Classifications

• G02B5/3025

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• B28B11/0872

  Non-mechanical reshaping of the surface, e.g. by burning, acids, radiation energy, air flow, etc. · CPC title

• G02F1/093 Primary

  used as non-reciprocal devices, e.g. optical isolators, circulators (G02F1/0955 takes precedence) · CPC title

• B28B3/003

  Pressing by means acting upon the material via flexible mould wall parts, e.g. by means of inflatable cores, isostatic presses (isostatic presses in general B30B5/02) · CPC title

• C04B35/50

  based on rare-earth compounds {(non-oxide rare earth compounds C04B35/5156)} · CPC title