Optical Device Alignment via Coupling Efficiency Derivatives

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for aligning optical devices in free space optical communications are time-consuming and prone to errors, especially when modules move or the propagation medium is turbulent, relying on trial-and-error and feedback-based incremental adjustments.

Innovation Solution

A method and apparatus that determine derivatives of coupling efficiency as a function of beam direction and focus parameters, inducing oscillating components to adjust the beam direction and focus for optimal alignment, using processors and memory to calculate and implement adjustments iteratively until a predefined signal quality is achieved.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If incremental trial-and-error adjustments are used to align optical modules, then alignment can be achieved, but the process becomes time-consuming and lengthy

Engineering Contradiction:
Improvealignment accuracyVSAvoidalignment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies oscillating adjustments to optical parameters (such as beam direction or field of view) to modulate the coupling efficiency signal. By inducing controlled oscillations and detecting the resulting signal variations, the system can determine the direction and magnitude of adjustments needed to maximize alignment, eliminating time-consuming trial-and-error incremental adjustments.

Inventive Principle:
Principle #18Mechanical vibration

2Reliability

If feedback-based incremental adjustments are used for alignment, then alignment can be established, but the number of communication iterations between modules increases

Engineering Contradiction:
Improvealignment accuracyVSAvoidalignment speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent utilizes feedback from the coupling efficiency signal between transmitter and receiver modules. By monitoring how the received signal strength varies in response to oscillating adjustments of optical parameters, the system determines the optimal alignment state and makes direct adjustments to reach maximum coupling efficiency, significantly reducing the number of communication iterations required compared to conventional feedback-based incremental methods.

Inventive Principle:
Principle #23Feedback

3Reliability

If conventional alignment methods are used, then alignment can be achieved under stable conditions, but the system becomes vulnerable to errors when modules move or propagation medium is turbulent

Engineering Contradiction:
Improvealignment stabilityVSAvoidrobustness to environmental changes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent employs dynamic oscillating adjustments of optical parameters rather than static alignment settings. By continuously modulating parameters and responding to real-time coupling efficiency feedback, the system can adapt to moving modules and turbulent propagation conditions, maintaining alignment robustness that conventional static alignment methods cannot provide.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2997675B1Alignment of optical devices
Publication Date: 2022.07.13 NOKIA TECHNOLOGIES OY
  • EP2997675B1 patent drawingFigure 1a~1b
  • EP2997675B1 patent drawingFigure 2~3
  • EP2997675B1 patent drawingFigure 4a~5b

AI summary

Adjustment of an optica! component of a device comprises determining of at least one derivative of coupling efficiency of the optical component as a functson of parameters used for control of a steering function of the optica! component. At least one oscillating component is induced into the parameters for the determining. The adjustment of the optical component is based on the determined at least one derivative.