Fiber Optical Package Interconnect Using Polarization Transformer

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Solution Overview

Problem

Conventional optical fiber interconnects require manual adjustment and are complex to align, especially when connecting multiple fibers with different polarization states, due to their sensitivity to rotational alignment and birefringence, which increases manufacturing costs and time.

Innovation Solution

The use of low-birefringence optical fibers, also known as spun fibers, which maintain polarization states regardless of orientation, combined with polarization transformers to convert between circularly and linearly polarized light, allowing for automatic alignment and simplified connection of optical fibers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional optical fiber interconnects are used, then polarization maintaining capability is achieved, but manual adjustment and complex alignment are required

Engineering Contradiction:

Improvepolarization maintaining capabilityVSAvoidalignment complexity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the polarization state parameter from linear to circular by introducing a polarization transformer (quarter-wave plate). This parameter change eliminates the sensitivity to rotational alignment, allowing the fiber to maintain polarization capability without requiring precise manual alignment during connection.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If conventional optical fiber interconnects are used, then polarization maintaining capability is achieved, but manufacturing time and costs increase

Engineering Contradiction:

Improvepolarization maintaining capabilityVSAvoidmanufacturing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The polarization transformer is pre-integrated into the fiber optic connector assembly during manufacturing. This preliminary action converts linearly polarized light to circularly polarized light before the fiber connection is made, eliminating the need for time-consuming manual alignment procedures during actual fiber optic system assembly and deployment.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If conventional optical fiber interconnects are used, then polarization maintaining capability is achieved, but device complexity increases

Engineering Contradiction:

Improvepolarization maintaining capabilityVSAvoidalignment mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a polarization transformer (quarter-wave plate) as an intermediary component between the light source and the optical fiber. This intermediary converts the polarization state of light from linear to circular, thereby mediating the interaction between light and fiber to eliminate sensitivity to rotational misalignment without requiring complex alignment mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Measurement precision

If manual rotational alignment is required, then polarization accuracy is maintained, but ease of connection decreases

Engineering Contradiction:

Improvepolarization accuracyVSAvoidease of connection

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent changes the polarization parameter from linear to circular using a quarter-wave plate. Circularly polarized light has rotational symmetry, which means its polarization characteristics remain consistent regardless of the fiber's rotational orientation. This parameter change maintains polarization accuracy while dramatically simplifying the connection process by eliminating the need for manual rotational alignment.

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 solution simplifies the connection of multiple optical fibers by eliminating the need for manual rotational alignment, reducing manufacturing time and costs, and enabling high integration and low power consumption in optoelectronic modules while maintaining polarization accuracy.

Implementation Method 1

a polarization transformer coupled between the optical component and the optical fiber, wherein the polarization transformer is configured to transform between a substantially circularly-polarized light at the low-birefringence optical fiber and a substantially linearly-polarized light at the optical component

Methodology Applied

Scientific EffectPolarization transformation: Polarisation

Implementation Method 2

a low-birefringence optical fiber; and a polarization transformer coupled between the optical component and the optical fiber, wherein the polarization transformer is configured to transform between a substantially circularly-polarized light at the low-birefringence optical fiber

Methodology Applied

Scientific EffectLow-birefringence propagation: Birefringence

Data Source

PatentUS9207461B2Fiber optical package interconnect

Publication Date: 2015.12.08 CIENA CORP

AI summary

Optical devices and systems including a polarization maintaining interconnect are disclosed. An optical assembly can include an optical component, a low-birefringence optical fiber and a polarization transformer. The polarization transformer is coupled between the optical component and the optical fiber. The polarization transformer is configured to transform between a substantially circularly-polarized light at the low-birefringence optical fiber and a substantially linearly-polarized light at the optical component.