Interferometer Using Copied Optical Patterns on Plane Plates
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Solution Overview
Problem
Existing interferometers require complex and costly production of polarization beam splitter cubes and triple prisms, with precise alignment and low-drift mounting, and are prone to unwanted interference in distance signals due to the use of optical components.
Innovation Solution
The interferometer design uses transparent plane plates with grating lenses and reflectors, eliminating the need for complex optical components like beam splitter cubes and triple prisms, and incorporating diffractive retroreflectors to reduce interference by separating diffraction orders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If polarization beam splitter cubes and triple prisms are used, then measurement precision is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent replaces complex optical components (beam splitter cubes, triple prisms) with simpler plane plates that have optical patterns copied onto their surfaces. These patterns replicate the functional properties of the complex components but are much easier to manufacture and align, thereby reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The patent substitutes mechanical optical components (physical beam splitter cubes and prisms requiring precise mechanical alignment) with plane plates featuring optical patterns. This replacement eliminates the need for complex mechanical mounting and alignment procedures, significantly simplifying the device while preserving its measurement capabilities.
2Measurement precision
If polarization beam splitter cubes and triple prisms are used, then measurement precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent copies the optical functionality of complex components onto simple plane plates through surface patterns. These patterns can be manufactured using standard lithography or printing techniques, making production significantly easier and more cost-effective while maintaining the precise optical behavior needed for accurate measurements.
Solution Approach 2:
The patent employs inexpensive plane plates with printed or lithographed optical patterns instead of expensive, labor-intensive optical components. These simpler components are easier to replace if needed and reduce overall manufacturing costs while achieving the same measurement precision.
3Device complexity
If beam splitter cube and triple prism are arranged directly on each other, then device complexity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent transfers the optical functionality of multiple aligned components onto single plane plates through copied optical patterns. This eliminates the need for precise physical alignment between separate components, as the optical paths are defined by the patterns themselves, thereby maintaining simplified device structure without demanding extreme manufacturing precision.
4Ease of operation
If large tilting tolerances are required, then ease of operation is improved, but device size increases
Solution Approach 1:
The patent uses optical patterns copied onto plane plates that define beam paths and optical references. These patterns can be designed to be insensitive to tilting within certain ranges, allowing larger operational tolerances without requiring oversized physical components, thus maintaining compact device size while improving ease of operation.
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 simplifies the manufacturing process, reduces production costs, and minimizes unwanted interference in distance signals, enabling more robust and cost-effective high-precision length measurement.
Implementation Method 1
A beam emitted by the light source is split by the beam splitter into at least one measuring beam and at least one reference beam
Implementation Method 2
The measuring beam falls perpendicularly onto the measuring reflector at least twice
Implementation Method 3
The reference arm has at least one reference retroreflector
Implementation Method 4
At least one first distance signal from the interfering measurement and reference beam bundles superimposed at the point of merger can be detected with the aid of the detector arrangement
Data Source
Figure 1a~1b
Figure 1c
Figure 2a~2d
AI summary
The present invention relates to an interferometer comprising a light source, a beam splitter, a measuring reflector, a reference retroreflector, a detector assembly, and two transparent planar plates. The beam splitter splits a first beam emitted by the light source into at least one measuring beam and at least one reference beam, over which a first splitting plane is defined. Until they rejoin at a point of convergence in a first convergence plane, the measuring beam propagates in a measuring arm and the reference beam propagates in a reference arm. The first convergence plane is oriented parallel to the first splitting plane. The measuring reflector, onto which the measuring beam is incident perpendicularly at least twice, is arranged in the measuring arm and connected to a measuring object that is movable along a measuring direction.The reference retroreflector, onto which the reference beam is incident at least once, is arranged in the reference arm. The detector arrangement allows for the detection of at least one first distance signal from the interfering measurement and reference beams superimposed at the point of convergence, with respect to the position of the object being measured. The first transparent planar plate and the second transparent planar plate are arranged parallel to each other in the beam path between the light source and the detector arrangement. The reference retroreflector is formed in the first planar plate, and the beam splitter is arranged on the second planar plate.