Integrated magneto-optic modulator/compensator system, methods of making, and methods of using the same

Patent metadata

Field	Value
Publication number	US-9668678-B2
Application number	US-201615213571-A
Country	US
Kind code	B2
Filing date	Jul 19, 2016
Priority date	Jan 31, 2014
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

Described herein is an integrated Faraday modulator and Faraday compensator (IFMC) system. Further described are methods of making an IFMC system, methods of customizing an IFMC system for a specific application, and methods of optimizing an IFMC system for a specific application. Further described is a robust 3D Finite Element Model (FEM) for designing and optimizing an IFMC system. Further described are optical instruments comprising an integrated Faraday modulator and Faraday compensator requiring only one optical crystal.

First claim

What is claimed is:

1. A method of conducting integrated Faraday modulation and Faraday compensation comprising:
generating a first magnetic field from an AC current;
generating a second magnetic field from a DC current; the second magnetic field being different from the first magnetic field, but existing in the same time and space as the first magnetic field; and
combining and superimposing the first magnetic field and the second magnetic field onto a single optical material.

2. A method of claim 1 , wherein the sample comprises a material having surface variations.

3. A method of claim 2 , wherein the material having surface variations comprises a thin film material.

4. A method of claim 1 wherein a component apparatus is adjustable to allow for an operational range for modulation between 0° and 2°.

5. A method of claim 1 , wherein a component apparatus is adjustable to allow for an operational range for compensation between 0° and 0.5° with sub-millidegree rotational sensitivity.

6. A method of claim 1 , wherein the method comprises achieving a modulation depth of about 1° and a maximum compensation depth of about 0.0632°, which is measured by the amount of compensation required to return an electric field back to a null position.

7. A method of claim 1 , wherein an AC power supply to the AC magnetic field source sustains a desired modulation depth to the magnetic fields being supplied to the optical material; and, wherein a DC power supply to the DC magnetic field source supplies a sub-millidegree rotational sensitivity to the magnetic fields being supplied to the optical material.

8. A method of measuring changes in a state of polarization of a beam of light, comprising:
generating a first magnetic field from an AC current;
generating a second magnetic field from a DC current; the second magnetic field being different from the first magnetic field, but existing in the same time and space as the first magnetic field; and
combining and superimposing the first magnetic field and the second magnetic field onto a single optical material.

9. A method of measuring changes in a state of polarization in a sample, comprising:
a) passing polarized light through a sample or reflected from a surface of the sample such that the state of polarization of the light is changed;
b) allowing the changed polarized light of step a) to pass through an optical material having a desired Verdet constant;
c) providing separate AC and DC magnetic field sources to the optical material; the AC magnetic source producing a first magnetic field for fast polarization modulation; and, the DC magnetic source producing a second magnetic field for polarization feedback compensation;
d) superimposing the separate first and second magnetic fields within the optical material as the polarized light of step b) passes through the optical material of step c);
e) passing the polarized light of step d) through an analyzer;
f) allowing the light of step e) to impinge onto a detector;
g) providing a feedback signal to at least one DC magnetic field source;
h) measuring changes in a state of polarization in the sample; and, optionally
i) adjusting at least one DC magnetic field source based on the feedback signal of step g).

10. A method of claim 9 , wherein changes in the state of polarization are calibrated, based on the feedback signal of step g), to one or more of: concentration of an analyte in the sample, layer thickness of the sample, surface characteristics of the sample, and material comprising the analyte and/or sample.

11. A method of claim 9 , wherein step h) includes varying ranges of modulation depths and/or varying ranges of compensation depths of one or more of the magnetic fields.

12. A method of claim 9 , further including step j) controlling modulation and compensation depth by varying one or more of parameters selected from:
coil permeability, conductivity, wire radius, or number of turns, in the AC and/or DC magnetic field sources;
location of the AC and/or DC magnetic field sources with respect to each other and/or to the optical material;
orientation of the AC and/or DC magnetic field sources with respect to each other and/or to the optical material; and,
current drive within the AC and/or DC magnetic field sources.

13. A method of claim 9 , wherein the sample is an optically active material.

14. A method of claim 13 , wherein the optically active material comprises glucose.

15. A method of claim 14 , wherein the glucose is present in aqueous humor of an eye, and the method comprises detection of glucose concentrations through the aqueous humor of the eye.

Assignees

• Univ Toledo

Inventors

• Cameron Brent D
• Clarke Brandon W

Classifications

• G02F1/09 Primary

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

• G01N2201/067

  Electro-optic, magneto-optic, acousto-optic elements · CPC title

• G02F1/092

  Operation of the cell; Circuit arrangements · CPC title

• G01N21/21

  Polarisation-affecting properties (G01N21/19 takes precedence) · CPC title

• G02F1/0136

  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