Variable Bandwidth Optical Filter Using Pivot Mechanisms
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Solution Overview
Problem
Traditional optical bandpass filters face challenges such as high manufacturing costs, fixed bandwidth and center wavelength, absorption issues, and optical misalignment due to complex multi-layer coatings and substrate curvature, which limit their effectiveness and flexibility in optical systems.
Innovation Solution
A variable bandwidth optical bandpass filter design incorporating two edge filters with pivot mechanisms, allowing for adjustable passband width by rotating the filters while maintaining optical alignment, utilizing thin multi-layer coatings on plane-parallel substrates to reflect specific wavelength ranges and reduce absorption and distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional multi-layer coating is used to achieve bandpass filtering, then the filtering performance is improved, but the manufacturing cost and complexity increase significantly
Solution Approach 1:
The patent divides the traditional single complex multi-layer bandpass filter into two separate edge filters, each with a simpler coating structure. One edge filter transmits wavelengths above a first cutoff wavelength, while the other transmits wavelengths below a second cutoff wavelength. This segmentation reduces the complexity of individual filter coatings while maintaining the overall bandpass filtering performance.
Solution Approach 2:
The patent combines two relatively simple edge filters to achieve the functionality of a complex multi-layer bandpass filter. By positioning these edge filters in series within the optical path, the system achieves bandpass filtering with reduced manufacturing complexity compared to a single traditional multi-layer filter.
2Adaptability or versatility
If the bandwidth of a traditional optical bandpass filter is adjusted, then the filtering selectivity is improved, but optical misalignment occurs due to beam deviation
Solution Approach 1:
The patent introduces a movable support structure that allows dynamic adjustment of the relative positioning between the two edge filters. By moving one edge filter relative to the other along the optical path, the overlapping region of their transmission bands can be adjusted, thereby controlling the passband width dynamically without causing optical misalignment.
Solution Approach 2:
The patent uses a movable support as an intermediary mechanism between the two edge filters. This support enables precise control of the filters' relative positions, allowing bandwidth adjustment while maintaining proper optical alignment and preventing beam deviation issues.
3Adaptability or versatility
If gradient-thickness coatings are used to create variable bandwidth filters, then the bandwidth flexibility is improved, but manufacturing complexity and cost increase
Solution Approach 1:
Instead of using complex gradient-thickness coatings on single filters, the patent segments the filtering function into two edge filters with relatively simpler coatings. The bandwidth variability is achieved through mechanical positioning rather than complex coating structures, reducing manufacturing complexity.
Solution Approach 2:
The patent achieves bandwidth variability by changing the positional parameter of the edge filters relative to each other, rather than changing the physical structure of the coatings themselves. This approach simplifies manufacturing while maintaining the ability to vary the passband width.
4Device complexity
If transmissive filters are used for bandpass filtering, then the filter design is simplified, but absorption and beam deviation problems worsen
Solution Approach 1:
The patent inverts the traditional transmissive filter approach by using reflective edge filters. Instead of transmitting the desired band and blocking others, the edge filters reflect unwanted wavelengths while transmitting the passband. This inversion reduces absorption losses and beam deviation issues associated with thick transmissive coatings.
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 solution enables flexible adjustment of bandwidth without requiring optical realignment, reduces manufacturing complexity and costs, and minimizes beam deviation and absorption, maintaining sharp passband edges and reducing stress-related distortions.
Implementation Method 1
The filter coating 42 and the filter coating 52 may each be a multi-layer coating... the multi-layer filter coating 42 provided on the surface 40... the multi-layer filter coating 52 provided on the surface 50
Implementation Method 2
a coating containing multiple layers of optical materials... each layer progressively increases or decreases in thickness along the substrate
Implementation Method 3
The pivot mechanism 14 supports the member 12 for limited pivotal movement about a pivot axis 16... The pivot mechanism 14 can selectively pivot the member 12 a few degrees away from the illustrated center position
Implementation Method 4
Each of these filters has a gradient-thickness coating provided on a plane-parallel substrate... As a result of this relative movement, the width of the passband increases or decreases
Implementation Method 5
the substrate and/or coating materials may tend to absorb radiation in the ultra violet range
Data Source
AI summary
A path of travel for radiation extends to one optical element, then to another optical element, and then away from the latter. One of the optical elements is respectively reflective and non-reflective to radiation above and below a first wavelength, and the other is respectively reflective and non-reflective to radiation below and above a second wavelength. According to a different aspect, a path of travel for radiation extends to one of first and second optical elements, then to the other optical element, and then away from the latter. The first optical element is reflective and non-reflective to radiation on respective sides of a first wavelength, and the second optical element is reflective and non-reflective to radiation on respective sides of a second wavelength. The first optical element can tilt in relation to the path of travel to change the first wavelength.