Magneto-optical material, method for producing same and magneto-optical device

Patent metadata

Field	Value
Publication number	US-2016209683-A1
Application number	US-201414904504-A
Country	US
Kind code	A1
Filing date	Jun 5, 2014
Priority date	Jul 19, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

Provided is a magneto-optical material which does not absorb fiber laser light in a wavelength range of 0.9-1.1 μm and does not cause a thermal lens, while having a larger Verdet constant than TGG crystals, and which is suitable for constituting a magneto-optical device such as an optical isolator. This magneto-optical material is formed of a single crystal of a rare earth oxysulfide that is represented by formula (1) or a transparent ceramic which contains, as a main component, a rare earth oxysulfide that is represented by formula (1), and this magneto-optical material has a Verdet constant of 0.14 min/(Oe·cm) or more at the wavelength of 1,064 nm.
(Tb x R 1-x ) 2 O 2 S  (1)

(In the formula, x is 0.3 or more but less than 1; and R represents at least one rare earth element that is selected from the group consisting of yttrium, lutetium, gadolinium, holmium, scandium, ytterbium, europium and dysprosium.)

First claim

1 . A magneto-optical material which is characterized by comprising either a transparent ceramic containing as a primary component a rare-earth oxysulfide of formula (1) below or a single-crystal of a rare-earth oxysulfide of formula (1)
(Tb x R 1-x ) 2 O 2 S  (1)

(wherein x is 0.3 or more but less than 1, and R is at least one rare-earth element selected from the group consisting of yttrium, lutetium, gadolinium, holmium, scandium, ytterbium, europium and dysprosium), and having a Verdet constant at a wavelength of 1064 nm that is at least 0.14 min/(Oe·cm).

2 . The magneto-optical material of claim 1 which is characterized in that when laser light having a wavelength of 1064 nm is input thereto at a beam diameter of 1.6 mm, for an optical path length of 10 mm, the maximum input power of laser light which does not generate a thermal lens is 40 W or more.

3 . The magneto-optical material of claim 1 which, for an optical path length of 10 mm, has an in-line transmittance of light at a wavelength of 1064 nm that is at least 60%.

4 . A method for producing a magneto-optical material, comprising the steps of firing in a crucible terbium oxide powder, a rare-earth oxide powder of at least one rare-earth element selected from the group consisting of yttrium, lutetium, gadolinium, holmium, scandium, ytterbium, europium and dysprosium, and sulfur powder; grinding the fired powders to form a rare-earth oxysulfide material powder; pressing the rare-earth oxysulfide material powder into a predetermined shape; and then sintering and hot isostatic pressing the shaped powder to form a transparent ceramic sintered compact containing as a primary component a rare-earth oxysulfide of formula (1) below
(Tb x R 1-x ) 2 O 2 S  (1)

(wherein x is 0.3 or more but less than 1, and R is at least one rare-earth element selected from the group consisting of yttrium, lutetium, gadolinium, holmium, scandium, ytterbium, europium and dysprosium).

5 . A magneto-optical device which is constructed using the magneto-optical material of claim 1 .

6 . The magneto-optical device of claim 5 which is an optical isolator that comprises the magneto-optical material as a Faraday rotator and a polarizing material at front and back sides of the Faraday rotator on an optical axis thereof, and that can be used in a wavelength range of at least 0.9 μm and not more than 1.1 μm.

7 . The magneto-optical device of claim 6 , wherein the Faraday rotator has an antireflective coating on an optical face thereof.

Assignees

• Shinetsu Chemical Co

Inventors

• Ikari Masanori

Classifications

• C01F17/294

  Oxysulfides · CPC title

• C04B35/547

  based on sulfides or selenides {or tellurides} · CPC title

• C04B2235/3225

  Yttrium oxide or oxide-forming salts thereof · CPC title

• C30B29/46

  Sulfur-, selenium- or tellurium-containing compounds · CPC title

• C04B2235/608

  Green bodies or pre-forms with well-defined density · CPC title