Wavelength Conversion via Orthogonal Polarization Cross-Phase Modulation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current wavelength conversion techniques in optical communication face challenges such as increased power consumption and signal quality deterioration due to limitations in conversion band and efficiency, particularly when using optical to electrical and electrical to optical signal conversion, and nonlinear optical effects, which also lead to issues like induced Brillouin scattering.

Innovation Solution

A wavelength conversion device utilizing a control-light generator that outputs continuous oscillation lights with orthogonal polarized waves and aligned phase modulation timings to cross-phase modulate input signal light through a nonlinear optical medium, allowing for efficient wavelength conversion without polarization dependency and reduced noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the intensity of control light is increased to improve conversion efficiency, then conversion efficiency is improved, but induced Brillouin scattering occurs causing signal quality deterioration

Engineering Contradiction:

Improveconversion efficiencyVSAvoidsignal quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The control light is divided into two independent continuous oscillation lights with orthogonal polarized waves. Each light independently cross-phase modulates the signal light through the nonlinear optical medium, allowing the system to achieve high conversion efficiency while distributing the optical power to avoid induced Brillouin scattering that would occur with a single high-intensity control light

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses a nonlinear optical medium that exploits the cross-phase modulation effect, combining the properties of optical nonlinearity with polarization orthogonality to achieve efficient wavelength conversion without the harmful effects of single-high-intensity control lights

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If optical to electrical and electrical to optical signal conversion is used to achieve wavelength conversion, then desired wavelength can be generated, but power consumption increases and conversion band is limited

Engineering Contradiction:

Improvewavelength conversion flexibilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The invention replaces the optical-to-electrical-to-optical conversion process with a direct optical-domain wavelength conversion using cross-phase modulation in a nonlinear optical medium. This eliminates the need for electrical circuitry and power-intensive modulators, achieving wavelength conversion with significantly lower power consumption and broader frequency band capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the fundamental parameter of wavelength conversion from electrical signal processing to optical field interaction. By using cross-phase modulation, the system directly manipulates optical parameters (frequency, wavelength) without converting to electrical domain, enabling flexible wavelength conversion across wide frequency bands with low power consumption

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances conversion efficiency while maintaining signal quality, reduces power consumption, and enables wavelength conversion across a wide frequency band without the need for light/electricity/optical signal conversion circuits, minimizing noise components like induced Brillouin scattering.

Implementation Method 1

a nonlinear optical medium that cross-phase modulates the input signal light with the first continuous oscillation light and the second continuous oscillation light and generates the output signal light

Methodology Applied

Scientific EffectCross-phase modulation: Electro-Optic Effects

Data Source

PatentUS10429721B2Wavelength conversion device, control-light generation device, wavelength conversion method, and control-light generation method

Publication Date: 2019.10.01 FUJITSU LTD

AI summary

A wavelength conversion device that converts input signal light having a first frequency into output signal light having a second frequency, includes: a control-light generator that outputs first continuous oscillation light and second continuous oscillation light; and a nonlinear optical medium that cross-phase modulates the input signal light with the first continuous oscillation light and the second continuous oscillation light and generates the output signal light, wherein the control-light generator outputs the first continuous oscillation light and the second continuous oscillation light to have polarized waves in directions orthogonal to each other and have a frequency interval equal to a difference between the first frequency and the second frequency and controls, based on intensity of the output signal light, timings of modulation of phases of the first continuous oscillation light and the second continuous oscillation light to be aligned with each other.