Magneto-optical propagation mode converter

• US 3,995,936 A
• Filed: 08/05/1975
• Issued: 12/07/1976
• Est. Priority Date: 08/09/1974
• Status: Expired due to Term

• Current Assignee: Thomson-CSF
• Original Assignee: Thomson-CSF
• Inventors: Desormiere, Bernard, Hepner, Georges
• Primary Examiner(s): Nelms, David C.
• Application Number:
  US05/602,009
• Time in Patent Office: 490 Days
• Field of Search: 250/227, 350/96 R, 350/96 B, 350/96 WG, 350/160, 350/151, 350/157, 307/88.3
• US Class Current: 385/6
• CPC Class Codes: G02F 1/0955 used as non-reciprocal devices, e.g. optical isolators, circulators

Abstract

A device for converting the propagation mode of radiated energy, ulitizing the Cotton-Mouton effect. It is constituted by a substrate upon which there is deposited an epitaxially produced film of yttrium-iron garnet, magnetized in a direction having at least one component normal to the direction of energy propagation, and with a thickness such that the propagation velocities of the two modes, initial and final, are identical to one another.

Claims

1. A device for at least partially converting the propagation mode of radiated energy, utilising magneto-optical effects, from a first mode to a second mode, said device comprising a layer of a ferrimagnetic material in which the radiated energy is guided in accordance with the first mode, the magnetisation of said layer exhibiting at least one component in a direction normal to the propagation direction of said radiated energy, the thickness of said layer being such that the propagation velocities of the radiated energy, in first of second modes, are substantially equal.

2. A device as claimed in claim 1, wherein said ferrimagnetic material is a ferrimagnetic garnet.

3. A device as claimed in claim 2, wherein said ferrimagnetic garnet is a yttrium-iron garnet.

4. A device as claimed in claim 1, further comprising a substrate for said layer of ferrimagnetic material, said substrate being constituted by a gadolinium and gallium garnet.

5. A device as claimed in claim 4, wherein said ferrimagnetic material layer is an anisotropic epitaxial layer.

6. A device as claimed in claim 1, wherein said magnetisation is orientated in a direction substantially parallel to the plane of said layer.

7. A device as claimed in claim 1, wherein the direction of said magnetisation is substantially contained in a plane normal to said radiated energy propagation direction.

8. A device as claimed in claim 7, wherein the direction of said magnetisation makes an angle of substantially 45°

with the plane of layer.