A Faraday rotator and an optical isolator having a high transmittance and a high Verdet constant are provided. The optical isolator includes at least a Faraday rotator that rotates a polarization plane of incident light in a non-reciprocal manner, a polarizer disposed on a light incident side of the Faraday rotator, and an analyzer disposed on a light exit side of the Faraday rotator. The Faraday rotator is made of an oxide containing ytterbium oxide (Yb.sub.2O.sub.3), and is manufactured by a ceramic manufacturing process, wherein the oxide is allowed to contain an oxide of a metal other than ytterbium, and the proportion of ytterbium in all metal atoms in the oxide is 80% or more.

A starting material powder, which contains a rare earth oxide that is composed of terbium oxide and at least one other rare earth oxide selected from among yttrium oxide, scandium oxide and oxides of lanthanide rare earth elements (excluding terbium) and a sintering assistant that is formed of an oxide of at least one element selected from among group 2 elements and group 4 elements, is produced by having (a) terbium ions, (b) ions of at least one other rare earth element selected from among yttrium ions, scandium ions and lanthanide rare earth ions (excluding terbium ions) and (c) ions of at least one element selected from among group 2 elements and group 4 elements coprecipitate in an aqueous solution containing the components (a)-(c), then filtering and separating the coprecipitate, and subjecting the separated coprecipitate to thermal dehydration.

A magnetochromatic display including a first substrate, first magnetic field modulating devices, a second substrate, and a magnetochromatic layer is provided. The first substrate has first pixel regions. The first magnetic field modulating devices are respectively disposed on the first pixel regions. The second substrate is disposed opposite to the first substrate. The magnetochromatic layer is disposed between the first substrate and the second substrate.

A paramagnetic garnet-type transparent ceramic characterized by being a sintered body of a terbium-containing composite oxide represented by formula (1) in which the linear transmittance at a wavelength of 1,064 nm at an optical path length of 15 mm is 83% or higher.

(Tb.sub.1-x-ySc.sub.xCe.sub.y).sub.3(Al.sub.1-zSc.sub.z).sub.5O.sub.12(1)

(In the formula, 0<x<0.08, 0y0.01, 0.004<z<0.16.)

A collimation lens and an optical module of the collimation lens. The collimation lens includes a front convex aspheric lens, a first polarizing filter, a Faraday rotation (FR) crystal, a second polarizing filter, and a rear convex aspheric lens. The front convex aspheric lens is coupled to a first end face of the collimation lens, and the rear convex aspheric lens is coupled to a second end face of the collimation lens. The first polarizing filter is coupled between the front convex aspheric lens and the FR crystal, and the second polarizing filter is coupled between the FR crystal and the rear convex aspheric lens.

An array substrate and a magneto-optical switch display. The array substrate includes: a thin film transistor T, a coil connected with the thin film transistor, and a magneto-optic crystal interposed in the coil, the coil and the magneto-optic crystal constituting a magneto-optical switch structure, and the magneto-optical switch structure can change a transmission rate of emergent light transmitting through the array substrate.

A small, low-cost 1.5-stage optical isolator has, in a forward direction, incoming light and outgoing light polarization directions that are parallel. The isolator includes a first Faraday rotator, a first polarizer, a second Faraday rotator and a second polarizer arranged in order on a light transmission path, and a magnet arranged so as to apply a same-direction magnetic field to the first Faraday rotator and the second Faraday rotator. Faraday rotation in the first Faraday rotator and Faraday rotation in the second Faraday rotator occur in opposite directions.

This invention provides a transparent magnetooptical material that is suitable for use in a magnetooptical device such as an optical isolator. Said magnetooptical material comprises either a transparent ceramic consisting primarily of a complex oxide that can be represented by formula (1) or a single crystal of such a complex oxide. Said magnetooptical material does not absorb fiber-laser light in the 0.9-1.1 m wavelength range, does not cause heat lensing, and has a higher Verdet constant than TGG crystals, with a Verdet constant of at least 0.14 min/(Oe.Math.cm) at a wavelength of 1,064 nm.
Tb.sub.2R.sub.2O.sub.7(1)
(In formula (1), R represents one or more elements selected from among the group consisting of silicon, germanium, titanium, tantalum, tin, hafnium, and zirconium (but not silicon only, germanium only, or tantalum only)).

An article includes a reflector having a first surface, a second surface opposite the first surface, and a third surface; and a first selective light modulator layer external to the first surface of the reflector; wherein the third surface of the reflector is open. A method of making an article is also disclosed.

In an embodiment, an arc light sensor includes: a first polarizer, a second polarizer, a magneto-optical material, a first light filter and a processing unit. The first polarizer is used for polarizing incident first target light, to form first polarized light in a first polarization direction. The second polarizer is used for polarizing incident second target light, to form second polarized light in the first polarization direction. The magneto-optical material, in a current magnetic field, uses the current magnetic field to rotate a polarization direction of the first polarized light, to form third polarized light. The first light filter is used for filtering the third polarized light, to form fourth polarized light capable of passing in a second polarization direction. The processing unit is used for determining whether the second target light is arc light according to intensity of the second polarized light and intensity of the fourth polarized light.