Stepped Optical Filter With Monolithic Spacer for Wavelength Flexibility

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Solution Overview

Problem

Existing binary multispectral filters face issues with excessive size, cost, and reduced optical performance due to imperfections caused by multiple layers of spacer material deposition, limiting flexibility in capturing desired wavelengths.

Innovation Solution

A multispectral filter design featuring a stepped medium with a monolithic spacer and a translatable second mirror, allowing for a variable gap between mirrors, which reduces imperfections and enables dynamic reconfiguration of wavelength channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple layers of spacer material are deposited to form a binary multispectral filter, then the filter can capture multiple wavelengths, but the filter size increases and manufacturing complexity increases

Engineering Contradiction:

Improvewavelength capture capabilityVSAvoidfilter structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The filter structure is segmented into distinct functional layers: a substrate, a stepped medium with multiple height levels corresponding to different wavelength channels, and a monolithic spacer layer. This segmentation allows each layer to perform a specific function independently, reducing overall complexity while maintaining multi-wavelength capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent merges the spacer function into a single monolithic layer that spans across all wavelength channels simultaneously. Instead of having separate spacer layers for each wavelength channel, one monolithic spacer layer serves all channels, reducing the total number of layers and simplifying the manufacturing process.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If multiple layers of spacer material are deposited, then the filter can be configured for multiple wavelengths, but surface oxidation imperfections increase and optical performance decreases

Engineering Contradiction:

Improvewavelength channel configurationVSAvoidoptical performance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts the spacer material from multiple separate deposited layers and consolidates it into a single monolithic spacer layer. This extraction of the spacer function into one layer eliminates the repeated deposition processes that cause surface oxidation, thereby improving optical performance while maintaining multi-wavelength configuration capability.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If a fixed binary multispectral filter is used, then the structure is simple, but the flexibility to capture desired wavelengths is limited

Engineering Contradiction:

Improvefilter structure simplicityVSAvoidwavelength selection flexibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic adjustability by making the second mirror translatable relative to the first mirror along the optical axis. This allows the gap between mirrors to be dynamically changed, which in turn adjusts the resonant wavelengths of the filter. This dynamic capability provides flexibility in wavelength selection while maintaining a relatively simple overall structure.

Inventive Principle:

Principle #15Dynamics

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 improves optical performance by minimizing surface oxidation and reducing size and cost while enhancing the flexibility to capture multiple spectral bands.

Implementation Method 1

A stepped structure optical filter may be provided. The stepped structure optical filter may include a substrate. The stepped structure optical filter may include a stepped medium disposed on the substrate. The stepped structure optical filter may include a first mirror disposed on the stepped medium.

Methodology Applied

Scientific EffectOptical interference: Interference

Implementation Method 2

The filter may include a first mirror disposed on the stepped medium. The first mirror may form a stepped mirror surface. Each step, of the stepped mirror surface may correspond to a channel, of a set of channels, of the filter.

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 3

The variable spacer filter may include a second mirror disposed on a second substrate and alignable to the first mirror. A cavity may separate the first mirror and the second mirror. The second mirror may be translatable with respect to the first mirror such that a spacing between the first mirror and the second mirror is variable.

Methodology Applied

Scientific EffectOptical path difference:

Data Source

PatentUS12436328B2Stepped structure optical filter

Publication Date: 2025.10.07 VIAVI SOLUTIONS INC(US)

AI summary

A filter may include a substrate. The filter may include a stepped medium disposed on the substrate. The filter may include a first mirror disposed on the stepped medium. The first mirror may form a stepped mirror surface. Each step, of the stepped mirror surface may correspond to a channel, of a set of channels, of the filter. The filter may include a spacer disposed on the stepped mirror surface. The filter may include a second mirror disposed on another surface of the spacer.