Optical Wavelength Selective Switches Guard Band Crosstalk

Solution Overview

Problem

Current optical wavelength selective switches face challenges in minimizing crosstalk and optical diffractive losses due to varying refractive index modulation periods across neighboring pixel regions, leading to light misdirection and attenuation issues.

Innovation Solution

Incorporating a guard band of pixel regions with a uniform voltage applied across them, positioned between neighboring pixel regions, to reduce crosstalk and modulate refractive indexes in a controlled manner, thereby directing light to specific output ports effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If refractive index modulation is applied across neighboring pixel regions to direct light to different output ports, then light routing capability is improved, but crosstalk and optical diffractive losses increase due to varying modulation periods at boundaries

Engineering Contradiction:

Improvelight routing capabilityVSAvoidoptical diffractive losses

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The liquid crystal layer is divided into discrete pixel regions with independent voltage control. By segmenting the modulation function across separate pixel regions, the patent enables precise control of refractive index at different locations while isolating the modulation effects to minimize boundary interference and crosstalk.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate pixel regions between high and low modulation zones to transition the refractive index gradually. These intermediary regions reduce abrupt changes at boundaries, minimizing optical diffractive losses and crosstalk while maintaining the ability to route light to different output ports.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If refractive index modulation is applied across neighboring pixel regions to direct light to different output ports, then light routing capability is improved, but crosstalk increases due to varying modulation periods at boundaries

Engineering Contradiction:

Improvelight routing capabilityVSAvoidcrosstalk

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The liquid crystal layer is divided into discrete pixel regions with independent voltage control. By segmenting the modulation function across separate pixel regions, the patent enables precise control of refractive index at different locations while isolating the modulation effects to minimize boundary interference and crosstalk.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate pixel regions between high and low modulation zones to transition the refractive index gradually. These intermediary regions reduce abrupt changes at boundaries, minimizing optical diffractive losses and crosstalk while maintaining the ability to route light to different output ports.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The solution effectively reduces crosstalk and optical diffractive losses, enhancing the accuracy and efficiency of light routing in optical wavelength selective switches by maintaining a consistent voltage across the guard band, which is set near the average of the maximum and minimum voltages applied to neighboring pixel regions.

Implementation Method 1

an optical wavelength separator configured to substantially direct individual wavelength ranges of light received at an input optical port to separate lateral areas of the layer of liquid crystal

Methodology Applied

Scientific EffectWavelength separation: Dispersion (of waves)

Implementation Method 2

a layer of liquid crystal having a two-dimensional array of electrically operable pixel regions... the electronic controller is configured to apply the voltages such that at least one neighboring pair of the lateral areas have refractive indexes modulated along a first direction

Methodology Applied

Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentUS10505656B2Optical wavelength selective switches with guard bands

Publication Date: 2019.12.10 NOKIA SOLUTIONS & NETWORKS OY

AI summary

An apparatus includes an optical wavelength selective switch that includes an optical wavelength separator, a layer of liquid crystal having a two-dimensional array of s electrically operable pixel regions, and an electronic controller connected to individual apply voltages across the pixel regions. The optical wavelength separator is configured to substantially direct individual wavelength ranges of light received at an input optical port to separate lateral areas of said layer of liquid crystal. The electronic controller is configured to apply the voltages such that at least one neighboring pair of the lateral areas have refractive indexes modulated along a first direction and are separated by a guard band of the pixel regions along a different second direction.