Optical encoder devices and systems

Patent metadata

Field	Value
Publication number	US-11575438-B2
Application number	US-202117500777-A
Country	US
Kind code	B2
Filing date	Oct 13, 2021
Priority date	Aug 8, 2019
Publication date	Feb 7, 2023
Grant date	Feb 7, 2023

Abstract

Devices, systems and methods for encoding information using optical components are described. Information associated with a first optical signal (e.g., an optical pump) is encoded onto the phase of a second optical signal (e.g., an optical probe) using cross phase modulation (XPM) in a non-linear optical medium. The optical signals are multiplexed together into the nonlinear optical medium. The probe experiences a modified index of refraction as it propagates through the medium and thus accumulates a phase change proportional to the intensity of the pump. The disclosed devices can be incorporated into larger components and systems for various applications such as scientific diagnostics, radar, remote sensing, wireless communications, and quantum computing that can benefit from encoding and generation of low noise, high resolution signals. Examples of the encoded information includes intrinsic noise from the optical source, or others signals of interest, such as electrical, optical, X-ray, or high-energy particle signals.

First claim

What is claimed is:

1. An optical encoder, comprising:
an optical multiplexer to receive an optical pump signal and an optical probe signal;
a non-linear optical medium coupled to an output of the optical multiplexer and configured to effect phase modulation onto the optical probe signal in accordance with the optical pump signal, wherein a timing of the optical pump signal and the optical probe signal is engineered such that one of the optical pump signal or optical probe signal trails the other of the optical pump signal or the optical probe signal upon entry into the non-linear optical medium, the non-linear optical medium further configured to effectuate a change in relative timing of the optical pump and the optical probe signals that traverse therethrough to produce an output consisting of modified versions of the optical pump signal and the optical probe signal; and
a demultiplexer coupled to the output of the non-linear optical medium to produce a phase-modulated probe signal.

2. The optical encoder of claim 1 , wherein the change in relative timing of the optical pump and optical probe signals improves a uniformity of phase modulation of the optical probe signal.

3. The optical encoder of claim 1 , wherein the change in relative timing is characterized by one of the following:
each pulse from the optical probe signal upon entry into the non-linear optical medium trails a corresponding pulse of the optical pump signal but leads the corresponding pulse of the optical pump signal upon exit from the non-linear optical medium, or
each pulse from the optical pump signal upon entry into the non-linear optical medium trails a corresponding pulse of the optical probe signal but leads the corresponding pulse of the optical probe signal upon exit from the non-linear optical medium.

4. The optical encoder of claim 1 , wherein the optical probe signal has a first center wavelength and the optical pump signal has a second center wavelength, and wherein an extent or degree of the change in relative timing is effectuated based on:
a value of the first center wavelength of the pump signal,
a value of the second center wavelength of the probe signal,
a wavelength separation between the first center wavelength of the pump signal and the second center wavelength of the probe signal,
a composition of materials of the non-linear optical medium, or
a dimension of the non-linear optical medium.

5. The optical encoder of claim 1 , wherein the change in relative timing is effectuated in-part according to a dispersive characteristic of the non-linear optical medium that corresponds to an optical dispersive element.

6. The optical encoder of claim 1 , configure to allow one of the optical pump signal and the optical probe signal traverse through the non-linear optical medium at a faster speed than the other of the optical pump signal and the optical probe signal, thus producing an overlap between the optical pump signal and the optical probe signal with a continuously changing relative time delay.

7. The optical encoder of claim 1 , wherein increasing a length of the non-linear medium produces an increase in the relative timing.

8. The optical encoder of claim 1 , wherein the non-linear optical medium includes a dispersive optical element as a part thereof.

9. The optical encoder of claim 1 , wherein the non-linear optical medium includes a χ3 non-linear medium as a part thereof.

10. The optical encoder of claim 1 , wherein the non-linear optical medium exhibits Kerr non-linearity.

11. The optical encoder of claim 1 , wherein the non-linear optical medium is configured to impart chromatic dispersion to the optical pump signal and the optical probe signal that propagate therethrough in a controlled way to improve signal to noise ratio.

Assignees

• L Livermore Nat Security Llc

Inventors

• Buckley Brandon Walter
• Perlmutter David Simon
• Setsuda Devore Peter Thomas
• Gowda Apurva Shantharaj
• Chou Jason Thomas

Classifications

• G02F2/004

  Transferring the modulation of modulated light, i.e. transferring the information from one optical carrier of a first wavelength to a second optical carrier of a second wavelength, e.g. all-optical wavelength converter · CPC title

• G02F1/212

  Mach-Zehnder type · CPC title

• G02F1/211

  Sagnac type · CPC title

• H04B10/2557 Primary

  Cross-phase modulation [XPM] · CPC title

• G02F1/225

  in an optical waveguide structure · CPC title