Wavemeter Using Cascaded Interferometer Cavities
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Solution Overview
Problem
High-speed and accurate measurement of light wavelengths is challenging in Fourier Domain Optical Coherence Tomography and swept wavelength distance measuring applications due to wavelength jitter, which affects the vertical resolution of axial-scans and requires precise measurement of interference signals at GHz rates.
Innovation Solution
A wavemeter system using multiple sets of interferometer cavities with different free spectral ranges, where each set provides a more accurate estimate of the light wavelength through cascaded analysis, allowing for concurrent measurement and refinement of wavelength estimates based on interference signals from multiple channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sets of interferometer cavities with different free spectral ranges are used, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The wavemeter system is segmented into multiple independent interferometer cavity sets (first set, second set, etc.), each with different free spectral ranges. Each set independently contributes to the wavelength measurement, allowing the system to achieve high precision through cascaded analysis while maintaining modular architecture that simplifies implementation.
Solution Approach 2:
The system extends the measurement capability by adding another dimension through multiple cavity sets with different free spectral ranges. Instead of relying on a single cavity, the patent uses cascaded analysis across multiple dimensional layers of interference patterns, where each cavity set provides complementary information that refines the wavelength estimate.
2Measurement precision
If multiple channels of light are distributed to multiple cavities, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple optical channels into a unified measurement system where light from the input beam is distributed to multiple interferometer cavities. The interference signals from all cavities are combined through cascaded analysis, allowing the system to extract precise wavelength information from the collective interference patterns while sharing common optical infrastructure.
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
Enables high-speed, precise measurement of light wavelengths with reduced uncertainty, supporting efficient linearization and post-correction of optical coherence tomography analyses by providing accurate wavelength information at high rates.
Implementation Method 1
measuring intensity of light reflected from the first pair of cavities and determining a first estimate of the wavelength or optical frequency based on measurements of interference signals
Implementation Method 2
measuring intensity of light reflected from the first pair of cavities
Data Source
AI summary
Method and apparatus for determining the wavelength of a light beam are provided. An input light beam is received, and light from the input light beam is distributed to multiple channels. At a first pair of interferometer cavities that has a first free spectral range, two of the multiple channels of light are received. The intensity of light reflected from the first pair of cavities is measured, and a first estimate of the wavelength or optical frequency of the input light beam is determined based on measurements of interference signals from the first pair of cavities and an initial estimate of the wavelength or optical frequency. At a second pair of cavities that has a second free spectral range smaller than the first free spectral range, another two of the multiple channels of light are received. The intensity of light from the second pair of cavities is measured, and a second estimate of the wavelength or optical frequency of the input light beam is determined based on the first estimate and measurements of interference signals from the second pair of cavities, in which the second estimate is more accurate than the first estimate.