Liquid Crystal Fiber Optic Assembly for Waveguide Coupling

Solution Overview

Problem

Current methods for aligning fiber optics in waveguide couples are either time-consuming and impractical for high-volume manufacturing (active alignment) or result in high light loss (passive alignment), which negatively impacts data transfer efficiency in data centers.

Innovation Solution

A fiber optic assembly that includes a transparent layer, a metal layer, a conductive electrode layer, and a liquid crystal layer, which is positioned between the conductive electrode layers to control the mode field diameter (MFD) and optimize light coupling into a waveguide.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If active alignment is used for fiber optic alignment, then light coupling efficiency is improved, but manufacturing time and complexity increase

Engineering Contradiction:

Improvelight lossVSAvoidalignment time

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-aligning the fiber optic core with the waveguide during the assembly manufacturing process, before the actual data center deployment. The fiber optic assembly is manufactured with predetermined alignment features that ensure proper positioning when installed, eliminating the need for time-consuming active alignment procedures at the installation site.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical active alignment system with a standardized mechanical interface system. The fiber optic assembly includes predefined mechanical features such as alignment pins, grooves, or indexed positioning structures that mechanically ensure proper alignment when the assembly is installed in the waveguide couple, substituting the need for manual mechanical adjustment procedures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If passive alignment is used for fiber optic alignment, then manufacturing speed is improved, but light coupling efficiency deteriorates

Engineering Contradiction:

Improvemanufacturing speedVSAvoidlight loss

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by pre-aligning the fiber optic core with the waveguide during the assembly manufacturing process, before the actual data center deployment. The fiber optic assembly is manufactured with predetermined alignment features that ensure proper positioning when installed, eliminating the need for time-consuming active alignment procedures at the installation site.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical active alignment system with a standardized mechanical interface system. The fiber optic assembly includes predefined mechanical features such as alignment pins, grooves, or indexed positioning structures that mechanically ensure proper alignment when the assembly is installed in the waveguide couple, substituting the need for manual mechanical adjustment procedures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If complex alignment procedures are used, then light coupling precision is improved, but device complexity increases

Engineering Contradiction:

Improvealignment precisionVSAvoidassembly complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the fiber optic assembly into distinct functional components with standardized interfaces. The assembly includes separate elements such as the fiber optic core, alignment features, protective layers, and coupling mechanisms that can be independently manufactured and assembled, simplifying the overall device complexity while maintaining alignment precision through standardized connection protocols.

Inventive Principle:

Principle #1Segmentation

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 fiber optic assembly effectively reduces light loss by optimizing the MFD and improving light coupling into the waveguide, thereby enhancing data transfer efficiency in data centers.

Implementation Method 1

adjusting, based on the potential difference, a position or an orientation of a molecule of the liquid crystal layer to direct light to a waveguide

Methodology Applied

Scientific EffectLiquid crystal molecular reorientation: Liquid Crystals

Data Source

PatentUS20250123509A1Liquid crystal based mode field diameter optimization

Publication Date: 2025.04.17 META PLATFORMS INC

AI summary

Methods and systems for a fiber optic assembly to propagate light into a waveguide associated with a photonic integrated circuit are provided. The system may include a fiber optic, and a fiber optic core for directing light into the fiber optic assembly. The fiber optic assembly may include at least one transparent layer, metal layer, electrode layer, or a liquid crystal layer. The fiber optic may be aligned in a photonic integrated circuit, where an active feedback loop may be configured to control regions of the fiber optic assembly individually based on the potential difference at both sides of the liquid crystal layer, via electrode layers. The molecules of the liquid crystal layer may be configured to move, change, or be reoriented to direct light into the waveguide based on the potential difference.