Optical Device Notch Filtering for Precise Signal Measurement

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Solution Overview

Problem

Existing optical signal measurement systems face challenges in accurately filtering specific wavelengths and measuring optical properties due to limitations from optical fiber size tolerance, structure errors, and camera resolution, which hinder precise analysis of optical signals.

Innovation Solution

A notch filter with a defect structure is integrated into a distributed Bragg reflector (DBR) stack, allowing for precise wavelength filtering and measurement of optical signals by controlling material and structural properties, including a defect refractive index and specific angles of incidence, enabling direct measurement of optical path angle, intensity, and divergence angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If optical fiber-based measurement systems are used, then signal transmission capability is improved, but measurement precision deteriorates due to optical fiber size tolerance and structure errors

Engineering Contradiction:

Improvesignal transmission capabilityVSAvoidoptical signal measurement precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent extracts the measurement function from the optical fiber transmission system by using the optical fiber itself as the measurement object. The back-reflected light from the optical fiber is analyzed to directly measure its structural properties, eliminating the need for separate measurement instruments that introduce tolerance errors.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The optical fiber performs self-measurement through its own back-reflection characteristics. By analyzing the wavelength-dependent back-reflection from the optical fiber's internal structure (core-cladding interfaces), the system enables the optical fiber to reveal its own geometric properties without external measurement devices, thereby achieving high precision measurement.

Inventive Principle:

Principle #25Self-service

2Device complexity

If conventional optical filtering methods are used, then device complexity is reduced, but measurement precision deteriorates due to camera resolution limitations

Engineering Contradiction:

Improvefiltering system complexityVSAvoidwavelength filtering precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the fundamental parameter from physical optical filtering (using cameras and filters with limited resolution) to wavelength-dependent back-reflection analysis. By exploiting the intrinsic interference patterns generated by the optical fiber's multi-layer structure at different wavelengths, the system achieves precise wavelength discrimination without conventional filtering hardware.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/optical filtering system (cameras, physical filters, lenses) with an analysis method based on back-reflection spectroscopy. Instead of using physical components to filter and measure light, the system uses the optical fiber's own back-reflection characteristics to encode wavelength information, eliminating resolution limitations of camera-based systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If direct optical measurement without wavelength filtering is used, then device complexity is reduced, but measurement precision deteriorates due to inability to filter specific wavelengths

Engineering Contradiction:

Improvemeasurement system complexityVSAvoidoptical property measurement precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent makes the simple back-reflection measurement system multi-functional by demonstrating that the same measurement approach can extract multiple optical properties (geometric parameters, refractive indices, layer thicknesses) from the optical fiber. The wavelength-dependent back-reflection spectrum serves as a comprehensive fingerprint that contains information about various structural parameters simultaneously.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 approach allows for accurate and reliable measurement of optical signals by filtering specific wavelengths and measuring optical properties without limitations from optical fiber size tolerance or camera resolution, enhancing the quality and reliability of optical signal analysis.

Implementation Method 1

a first distributed Bragg reflector (DBR) stack formed over the substrate, the first DBR stack including: a plurality of first layers, wherein at least one layer of the plurality of first layers is in physical contact with the substrate and at least one layer of the plurality of first layers is in physical contact with the defect structure, and a plurality of second layers

Methodology Applied

Scientific EffectBragg reflection: Bragg Diffraction

Implementation Method 2

Methodology Applied

Scientific EffectNotch filter effect: Filter (optical)

Implementation Method 3

an optical signal detector positioned adjacent to the notch filter

Methodology Applied

Scientific EffectOptical detection: Photoelectric Effect

Data Source

PatentUS20250251274A1Optical devices and methods of manufacture

Publication Date: 2025.08.07 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Optical devices and methods of manufacture are presented herein. In an embodiment, an apparatus is provided that includes a notch filter, an optical signal detector positioned adjacent to the notch filter, and a mirror positioned to adjacent to the notch filter.