Method for an optical modulator using the spin hall effect in metals

Patent metadata

Field	Value
Publication number	US-10139655-B2
Application number	US-201615140191-A
Country	US
Kind code	B2
Filing date	Apr 27, 2016
Priority date	Apr 30, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

The spin-Hall effect can be used to modulate the linear polarization of light via the magneto-optical Kerr effect. A material is illuminated while simultaneously passing a modulated electric current through the material, so that reflected light has a new linear polarization that differs from the initial linear polarization to a degree depending on the amplitude of the modulated electric current.

First claim

What is claimed is:

1. A method of modulating the linear polarization of a light source, comprising:
illuminating a central area of a spin Hall material with a light source to produce light arriving at the spin Hall material from a propagation direction that is not orthogonal to a plane of the spin Hall material and having an initial linear polarization, such that reflected light is cast from an outer surface of the spin Hall material, while simultaneously passing a modulated electric current through the spin Hall material in a direction perpendicular to the propagation direction, and
receiving the reflected light to assess its linear polarization,
wherein the reflected light has a new linear polarization that differs from the initial linear polarization to a degree depending on the amplitude of the modulated electric current, and
wherein the spin Hall material is selected from the group consisting of W film, Ta film, Pt film, Bi doped Cu film, IrMn film, Hf doped Pt film, and multiple layers of these films.

2. The method of claim 1 , wherein said receiving comprises receiving through a linear polarizer followed by a silicon photodiode having an output operably connected to a lock-in amplifier.

3. The method of claim 1 , wherein said spin Hall material comprises the W film, and more particularly comprises a β-phase tungsten film.

4. The method of claim 1 , wherein said spin Hall material has a spin Hall angle of at least 0.01.

5. The method of claim 1 , further comprising causing the reflected light to arrive at a surface of at least a second spin Hall material and to reflect therefrom prior to said receiving.

6. The method of claim 5 , further comprising causing the reflected light to arrive at a surface of at least a third spin Hall material and to reflect therefrom prior to said receiving.

7. The method of claim 1 , wherein the amplitude of the modulated electric current is within +/−100 mA.

Assignees

• Us Navy

Inventors

• Van'T Erve Olaf M J
• Li Connie H
• Jonker Berend T
• Hanbicki Aubrey T
• Mccreary Kathleen M

Classifications

• G02F1/0353

  involving an electro-optic TE-TM mode conversion · CPC title

• G02F1/0136 Primary

  for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation (G02F1/0353 takes precedence) · CPC title