Optical Module Offset Lens Astigmatism Compensation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional communication optical transceiver modules experience degradation in coupling efficiency due to astigmatism caused by the wavelength separating filter, especially when an aspheric lens is used, leading to inefficient signal transmission and reception.

Innovation Solution

The optical module design includes a light emitting element offset from the central axis of a lens, with a wavelength separating filter arranged at a predetermined angle relative to the optical fiber, which cancels astigmatism by adjusting the light emitting element's position to optimize coupling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a wavelength separating filter is arranged at a 45-degree angle to separate transmission and reception optical signals, then wavelength separation is achieved, but astigmatism is generated causing degradation of coupling efficiency to the optical fiber

Engineering Contradiction:

Improvesignal separation reliabilityVSAvoidcoupling efficiency

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by intentionally offsetting the light emitting element from the optical axis of the lens. This asymmetric positioning compensates for the astigmatism introduced by the 45-degree angled wavelength separating filter, thereby maintaining high coupling efficiency while preserving the filter's wavelength separation function

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent changes the positional parameter of the light emitting element relative to the lens optical axis. By adjusting this offset distance, the system compensates for astigmatism and optimizes coupling efficiency, transforming a fixed-axis configuration into an adjustable parameter that counteracts the filter-induced aberration

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 design effectively suppresses astigmatism-induced degradation, achieving higher coupling efficiency by compensating for aberrations generated by the wavelength separating filter, thereby enhancing signal transmission and reception performance.

Implementation Method 1

a lens for focusing light emitted from the light emitting element on the optical fiber via the wavelength separating filter

Methodology Applied

Scientific EffectLight: Light

Implementation Method 2

a lens for focusing light emitted from the light emitting element on the optical fiber

Methodology Applied

Scientific EffectFocusing: Focusing

Implementation Method 3

a wavelength separating filter for separating wavelengths of the transmission signal light and reception signal light

Methodology Applied

Scientific EffectWavelength separation: Filter (optical)

Implementation Method 4

downstream signal light output from the optical fiber is reflected at the wavelength separating filter

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS9341788B2Optical module

Publication Date: 2016.05.17 MITSUBISHI ELECTRIC CORP

AI summary

An optical module includes a light emitting element, an optical fiber, a wavelength separating filter that is arranged at a predetermined angle with respect to a longitudinal direction of the optical fiber on a plane including the longitudinal direction of the optical fiber, and a lens for focusing light emitted from the light emitting element on the optical fiber via the wavelength separating filter. The light emitting element is arranged while being offset in a direction perpendicular to a central axis of the lens on a plane where the wavelength separating filter has the predetermined angle with respect to the central axis of the lens.