On-Chip Optical Filter Using Fabry-Perot Resonators

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional spectrometers are heavy and not suitable for miniaturization, particularly for applications in smartphones or wearable devices, as they require a separate optical device and integrated circuit, necessitating research into on-chip spectrometer structures.

Innovation Solution

An on-chip optical filter utilizing a Fabri-Perot resonator structure with sub-wavelength grating (SWG) reflecting layers, where the first and second SWG reflecting layers with different refractive indices and duty cycles operate as Fabri-Perot resonators, transmitting light at a resonance wavelength, and optionally include a polarizing filter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If conventional spectrometer structures are used, then optical performance is maintained, but device weight and size increase

Engineering Contradiction:

Improvespectrometer weightVSAvoidoptical performance

Core Design Contradiction:

Weight of moving objectVSReliability

Solution Approach 1:

The patent merges the optical filter and spectrometer functions into a single integrated on-chip device. The Fabri-Perot resonator structure combines wavelength-selective filtering with spectral measurement capabilities, eliminating the need for separate optical components and reducing overall device weight while maintaining optical performance

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces traditional mechanical spectrometer components with photonic crystal-based optical structures. The Fabri-Perot resonator uses optical interference effects instead of mechanical moving parts, enabling miniaturization while preserving spectral analysis functionality

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Volume of moving object

If conventional spectrometer structures are used, then optical functionality is maintained, but device volume increases

Engineering Contradiction:

Improvespectrometer volumeVSAvoidintegration capability

Core Design Contradiction:

Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent implements a nested structure where the Fabri-Perot resonator is integrated within the on-chip spectrometer platform. The optical filter structure is embedded within the semiconductor chip architecture, allowing compact nesting of multiple functional elements in a hierarchical arrangement that minimizes device volume

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The on-chip Fabri-Perot resonator structure serves multiple functions simultaneously: it acts as both an optical filter for wavelength selection and a spectral analyzer for light detection. This multi-functionality reduces the need for separate components, enhancing integration capability while reducing device volume

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Manufacturing precision

If Fabri-Perot resonator structure is used, then resonance wavelength transmission is achieved, but manufacturing precision requirements increase

Engineering Contradiction:

Improveresonance wavelength controlVSAvoidfabrication complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent controls the resonance wavelength by adjusting geometric parameters of the Fabri-Perot resonator structure, such as cavity length and mirror reflectivity. By changing these physical dimensions during fabrication, precise wavelength control is achieved while using standard semiconductor manufacturing processes, balancing manufacturing precision with ease of fabrication

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

The on-chip optical filter achieves efficient light transmission at specific wavelengths, enhancing the performance of the Fabri-Perot resonator with a narrow bandwidth and controlled resonance wavelength, facilitating miniaturization and integration on a semiconductor chip, thereby addressing the weight and size issues of conventional spectrometers.

Implementation Method 1

The plurality of first sub-wavelength reflecting units and the plurality of second sub-wavelength reflecting units are aligned to face each other and operate as a plurality of Fabri-Perot resonators. Each of the Fabri-Perot resonators transmits light of a resonance wavelength set in advance.

Methodology Applied

Scientific EffectFabri-Perot resonance: Fabry-Perot Interferometer

Implementation Method 2

a first sub-wavelength grating (SWG) reflecting layer including a plurality of first sub-wavelength reflecting units, each of the first sub-wavelength reflecting units including a plurality of first reflectors that are spaced apart from each other at a regular interval

Methodology Applied

Scientific EffectSub-wavelength grating reflection: Diffraction Grating

Data Source

PatentUS9939587B2On-chip optical filter comprising Fabri-Perot resonator structure and spectrometer

Publication Date: 2018.04.10 SAMSUNG ELECTRONICS CO LTD

AI summary

An on-chip optical filter having Fabri-Perot resonators and a spectrometer may include a first sub-wavelength grating (SWG) reflecting layer and a second SWG reflecting layer facing each other. A plurality of Fabri-Perot resonators are formed by the first SWG reflecting layer and the second SWG reflecting layer facing each other. Each of the Fabri-Perot resonators may transmit light corresponding to a resonance wavelength of the Fabri-Perot resonator. The resonance wavelengths of the Fabri-Perot resonators may be determined according to duty cycles of grating patterns.