Optically-induced charge separation and induced magnetism in dielectrics for optical energy conversion and intense magnetic field generation

Patent metadata

Field	Value
Publication number	US-10038300-B2
Application number	US-201615019611-A
Country	US
Kind code	B2
Filing date	Feb 9, 2016
Priority date	May 14, 2010
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

Schemes are described to produce quasi-static charge separation, Terahertz radiation, and programmable magnetic field generation using linearly-polarized light in unbiased, transparent insulators. The methods exploit a recently-observed magneto-electric optical nonlinearity that produces intense magnetization in undoped, homogeneous dielectrics. Analysis reveals that strong magnetic effects can be induced at modest optical intensities even with incoherent light. Consequently, efficient solar power conversion is feasible without the semiconductor processing or electron-hole pair generation that is required in conventional photovoltaic cells. Additionally, conditions and techniques are described to generate intense THz radiation in unbiased substrates and large magnetic fields orientated transverse to the direction of propagation of light, without the need for any external permanent magnetic or electromagnetic apparatus.

First claim

What is claimed:

1. A reconfigurable magnetic field generator comprising:
an unbiased, non-conducting transparent substrate;
a laser source coupled to pump laser output into the substrate, the laser output having an intensity above a threshold for inducing saturated dipole magnetization in the substrate;
an optical modulator to control the pump laser output distribution in space, time, and frequency to effect a desired variation of an induced B field amplitude in the substrate; and
a programmable controller to control the modulator to control the distribution of the laser output and to produce a desired modulation of laser output cross-sectional and temporal intensity.

2. The magnetic field generator of claim 1 , wherein the substrate is a semiconductor and the laser output has a carrier wavelength selected to lie within the forbidden energy gap of the semiconductor.

3. The magnetic field generator of claim 1 , wherein the substrate is a dielectric material.

4. The magnetic field generator of claim 3 , wherein the dielectric material is transparent at optical wavelengths.

5. The magnetic field generator of claim 3 , wherein the dielectric material is non-transparent at optical wavelengths.

6. The magnetic field generator of claim 1 , wherein the substrate is a magnetic material that contains a static magnetization prior to pumping the laser output into the substrate.

7. The magnetic field generator of claim 1 , wherein the substrate is a magnetic material that does not contain a static magnetization prior to pumping the laser output into the substrate.

8. The magnetic field generator of claim 1 , wherein the programmable controller is configured to impart information on the laser output through control of the modulator, and wherein the information is stored as magnetic domain structures in the substrate.

9. The magnetic field generator of claim 8 , wherein a size and/or geometry of the magnetic domain structures in the substrate varies with the imparted information.

10. The magnetic field generator of claim 1 , wherein the programmable controller is configured to impart information on the laser output through control of the modulator, and wherein a size and/or geometry of a spatial distribution of the magnetic field in the substrate varies with the imparted information.

Assignees

• Univ Michigan Regents

Inventors

• Rand Stephen C
• Fisher William M

Classifications

• H02M7/06 Primary

  using discharge tubes without control electrode or semiconductor devices without control electrode · CPC title

• H02M7/003

  Constructional details, e.g. physical layout, assembly, wiring or busbar connections · CPC title

• Y02E10/56

  Power conversion systems, e.g. maximum power point trackers · CPC title

• G02F1/09

  based on magneto-optical elements, e.g. exhibiting Faraday effect · CPC title

• G02F1/3534

  Three-wave interaction, e.g. sum-difference frequency generation (G02F1/3532 takes precedence) · CPC title