Apparatus comprising a magneto-optic isolator utilizing a garnet layer
First Claim
1. Apparatus comprising a source of electromagnetic radiation, radiation utilization means, and magneto-optic isolator means between the source and the utilization means, the isolator means comprising polarizing means, magnet means and a magneto-optic member that comprises a single crystal magneto-optic garnet layer on a single crystal substrate;
- CHARACTERIZED IN THATthe garnet layer comprises at least a first and a second stratum of garnet material;
the first stratum having a first composition selected such that the lattice constant of the first stratum is, at a first temperature, substantially equal to the lattice constant of the substrate, and such that the lattice constant of the first stratum is, at a second temperature that is higher than the first temperature, larger than the lattice constant of the substrate;
the second stratum having a second composition selected such that the lattice constant of the second stratum is, at the first temperature, less than the lattice constant of the substrate, and such that the lattice constant of the second stratum is, at the second temperature, less than the lattice constant of the first stratum, wherein the first composition is (Bix B3-x)(Fe5-z Cz)O12 and the second composition is (Bix'"'"' B3-x'"'"')(Fe5-z Cz)O12, B being one or more rare earth elements (atomic number 57-71), optional C is chosen from the group consisting of Ga, Al, and combinations thereof, 1≦
x≦
2.5, 0≦
z≦
1, and 0<
x'"'"'<
x.
0 Assignments
0 Petitions
Accused Products
Abstract
Apparatus according to the invention comprises a magneto-optic isolator. The isolator comprises a magneto-optic member that comprises a single crystal substrate and a single crystal garnet layer on the substrate. The garnet layer comprises a first and a second stratum. The composition of the former is chosen such that the lattice constant of the first stratum material is substantially equal to that of the substrate at a first temperature (e.g., room temperature), and is substantially larger than that of the substrate at a second temperature (e.g., the garnet growth temperature) that is higher than the first temperature. The composition of the second stratum is chosen such that the lattice constant of the second stratum is less than that of the substrate at the first temperature, and is less than that of the first stratum at the second temperature. Wafers according to the invention typically are less subject to fracture than analogous prior art wafers.
20 Citations
8 Claims
-
1. Apparatus comprising a source of electromagnetic radiation, radiation utilization means, and magneto-optic isolator means between the source and the utilization means, the isolator means comprising polarizing means, magnet means and a magneto-optic member that comprises a single crystal magneto-optic garnet layer on a single crystal substrate;
-
CHARACTERIZED IN THAT the garnet layer comprises at least a first and a second stratum of garnet material;
the first stratum having a first composition selected such that the lattice constant of the first stratum is, at a first temperature, substantially equal to the lattice constant of the substrate, and such that the lattice constant of the first stratum is, at a second temperature that is higher than the first temperature, larger than the lattice constant of the substrate;
the second stratum having a second composition selected such that the lattice constant of the second stratum is, at the first temperature, less than the lattice constant of the substrate, and such that the lattice constant of the second stratum is, at the second temperature, less than the lattice constant of the first stratum, wherein the first composition is (Bix B3-x)(Fe5-z Cz)O12 and the second composition is (Bix'"'"' B3-x'"'"')(Fe5-z Cz)O12, B being one or more rare earth elements (atomic number 57-71), optional C is chosen from the group consisting of Ga, Al, and combinations thereof, 1≦
x≦
2.5, 0≦
z≦
1, and 0<
x'"'"'<
x. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
Specification