Optical Waveguide Interferometer for Nanometer Displacement Measurement
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Solution Overview
Problem
Current interferometers face issues with large volume, poor detection quality, low accuracy, and limited application scope due to light spot separation and susceptibility to environmental disturbances, especially in long-distance measurements.
Innovation Solution
An interferometer displacement measurement system utilizing a first and second laser light source, polarization splitting prisms, ¼ wave plates, splitting prisms, and optical waveguide components with plano-convex lenses and reflective films to process measurement and reference light, ensuring no light spot separation and reducing light spot size, thereby enhancing measurement accuracy and adaptability to environmental disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical components are used to convert angled light beams into parallel light beams, then stripe interference is eliminated, but light spot separation occurs and device volume increases
Solution Approach 1:
Instead of converting angled beams to parallel beams using additional optical components, the invention inverts the approach by directly detecting the angled interference spot pattern with a photoelectric detector array, accepting and measuring the angle-induced spatial distribution rather than eliminating it
Solution Approach 2:
The invention extracts only the necessary functional components for angle measurement, removing unnecessary optical conversion elements (lenses, mirrors) that were traditionally used to eliminate stripes, thereby reducing device volume while maintaining measurement capability
2Reliability
If light spot size is increased to prevent separation in long-distance measurement, then light spot separation is avoided, but wavefront quality deteriorates due to environmental factors
Solution Approach 1:
The invention replaces traditional optical-mechanical beam expansion methods with a direct detection approach using photoelectric detectors that can resolve angled interference patterns, eliminating the need to increase light spot size and thereby preserving wavefront quality against environmental disturbances
3Measurement precision
If pyramid prism is used to return light and prevent angle interference, then light parallelism is maintained, but device complexity and volume increase
Solution Approach 1:
The invention removes the pyramid prism and other complex optical return-path components, extracting only the essential laser source and direct detection elements, thereby simplifying the device structure while maintaining measurement precision through alternative optical path design
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
Achieves nanometer-level resolution with improved measurement accuracy and wider angle measurement range, reducing the impact of environmental disturbances and light spot separation, while maintaining high signal quality.
Implementation Method 1
a first polarization splitting prism, a first photoeletric detector, a first 1⁄4 wave plate, a first splitting prism
Implementation Method 2
a first 1⁄4 wave plate, a first splitting prism, an optical waveguide component
Implementation Method 3
an optical waveguide component and a reflector, disposed on one side of the first laser light source sequentially
Implementation Method 4
a first photoeletric detector generates a measurement signal according to the processed measurement light and the processed reference light
Implementation Method 5
a first laser light source for emitting measurement light; a second laser light source for emitting reference light
Data Source
AI summary
Interferometer displacement measurement system and method are disclosed, wherein, a measurement light is processed by a first polarization splitting prism, a first ¼ wave plate, a first splitting prism, an optical waveguide component and a reflector, and then is returned to a first photoeletric detector and a second photoeletric detector. The reference light is processed by a second polarization splitting prism, a second ¼ wave plate, a second splitting prism and a reflecting mirror, and then is returned to the first photoeletric detector and the second photoeletric detector. The first photoeletric detector forms a measurement signal according to the processed measurement light and the processed reference light, and the second photoeletric detector forms a reference signal according to the processed measurement light and the processed reference light. Displacement information of the object to be detected is determined according to the measurement signal and the reference signal.