Optical Interference Measurement with Shared Paths and Frequency Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-channel optical interference measurement apparatuses face challenges such as increased size, complexity, and cost due to the need for multiple components per channel, making them impractical for simultaneous measurement of multiple objects.
Innovation Solution
A multi-channel optical interference measurement apparatus is designed with a shared configuration of light source, detector, and processing unit, utilizing a fiber coupler to branch measurement light to multiple heads, with carefully set optical path lengths to ensure separate frequency ranges for each head, allowing for robust and accurate multi-channel measurement without increasing apparatus size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If optical components for providing reference light, detector, and processing unit are provided for each channel, then multi-channel measurement capability is achieved, but the number of components increases N-fold causing increase in apparatus size, structural complexity, and cost
Solution Approach 1:
The patent merges the reference light sources and signal processing systems into a shared configuration that serves multiple measurement heads simultaneously. Specifically, a single reference light source provides reference light to multiple interferometers, and a single detector with frequency analysis capability processes signals from all channels, thereby achieving multi-channel measurement without proportionally increasing the number of components
Solution Approach 2:
The reference light source and processing unit are designed to serve multiple functions across different measurement channels. The reference light source generates reference light that is distributed to multiple interferometric measurement paths, and the processing unit performs frequency analysis for all channels, making these components universal rather than channel-specific
2Adaptability or versatility
If optical path lengths of multiple measurement heads are set independently, then each head can measure its own range, but frequency ranges overlap making it difficult to extract individual ranging results
Solution Approach 1:
The patent applies local quality by assigning distinct optical path length characteristics to each measurement head's reference light path. Specifically, each measurement head is configured with a different optical path length for its reference light (S1, S2, ..., Sn), which creates locally differentiated frequency ranges in the spectrum that correspond to each head's measurement capability
Solution Approach 2:
The patent changes the optical path length parameter for each measurement head's reference light to achieve frequency separation. By setting different optical path lengths S1, S2, ..., Sn for the reference lights of different measurement heads, the resulting interference signals occupy different frequency ranges in the spectrum, enabling clear distinction and extraction of individual measurement results
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 configuration enables compact and cost-effective multi-channel measurement by simplifying signal processing and reducing noise, while improving measurement accuracy and robustness against temperature changes and oscillations.
Implementation Method 1
optical interference measurement apparatus... interference signals of the return light and reference light
Implementation Method 2
detector that is configured to receive an interference signal of the return light and reference light and to convert the interference signal into an electric signal
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
A multi-channel optical interference measurement apparatus is provided at low cost without incurring an increase in size of the apparatus. A first return light that is received by a first measurement head is guided to a detector via a first optical path and a fiber coupler, and a second return light that is received by a second measurement head is guided to the detector via a second optical path and the fiber coupler. An optical path length D1 from the fiber coupler to the leading end of the first measurement head, an optical path length D2 from the fiber coupler to the leading end of the second measurement head, a maximum optical path length Rlmax of the measurement range of the first measurement head, an optical path length S1 of the first reference light that interferes with the first return light, and an optical path length S2 of the second reference light that interferes with the second return light are set such that the relation D1+R1max−S1<D2−S2 is satisfied.