Distance Measuring Arrangement Using Phase Modulator
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Solution Overview
Problem
Existing distance measuring arrangements using mechanically moving components face limitations in precision, accuracy, and noise issues due to mechanical constraints and vibrations, which hinder effective measurement of distances and surface topologies.
Innovation Solution
A distance measuring arrangement employing a phase modulator that modulates the phase of a signal beam periodically without mechanically moving components, using a multiplexer to combine multiple monochromatic light beams of different wavelengths, and an electro-optic or acousto-optic phase modulator to enhance precision and accuracy by compensating for external influences and increasing measurement speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanically moving components are used to spatially modulate the measurement beam, then the measurement function can be implemented, but mechanical vibrations are produced leading to noise and measurement problems
Solution Approach 1:
The patent replaces the mechanical piezo actuator with an electro-optic phase modulator that uses electrical signals to modulate the phase of the light beam. This substitution eliminates mechanical moving parts while achieving the same spatial modulation function through electrical-optical interaction, thereby eliminating mechanical vibrations and noise.
Solution Approach 2:
The patent changes the modulation parameter from mechanical displacement to optical phase. By using an electro-optic phase modulator, the system modulates the phase of the light beam according to a sinusoidal function without any mechanical movement, transforming the control parameter from mechanical domain to optical domain.
2Ease of operation
If mechanically moving components are used for spatial modulation, then beam modulation is achieved, but measurement precision is limited due to mechanical constraints
Solution Approach 1:
The patent replaces the mechanical piezo actuator with an electro-optic phase modulator that uses electrical signals to modulate the phase of the light beam. This substitution eliminates mechanical moving parts while achieving the same spatial modulation function through electrical-optical interaction, thereby eliminating mechanical vibrations and noise.
Solution Approach 2:
The patent changes the modulation parameter from mechanical displacement to optical phase. By using an electro-optic phase modulator, the system modulates the phase of the light beam according to a sinusoidal function without any mechanical movement, transforming the control parameter from mechanical domain to optical domain.
3Measurement precision
If multiple monochromatic light beams of different wavelengths are combined, then measurement accuracy is improved through compensation of external influences, but device complexity increases
Solution Approach 1:
The patent combines multiple monochromatic light beams of different wavelengths (e.g., two wavelengths in the C-band or L-band) into a single measurement beam using optical coupling. This merging allows the system to perform multi-wavelength interferometry for improved measurement accuracy and compensation of environmental influences while maintaining a relatively simple optical architecture.
Solution Approach 2:
The patent uses a single phase modulator to modulate the phase of multiple wavelengths simultaneously, and a single detector to capture the interference signal from all wavelengths. This multi-functional approach enables the system to achieve enhanced measurement capabilities without proportionally increasing device complexity.
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 achieves improved precision and accuracy in distance measurement by compensating for external disturbances and allowing high-frequency phase modulation, reducing noise, and enabling faster measurement speeds without mechanical vibrations.
Implementation Method 1
A phase modulator that modulates the phase of the signal beam periodically in time... an electro-optic or acousto-optic phase modulator to enhance precision and accuracy
Implementation Method 2
an electro-optic or acousto-optic phase modulator to enhance precision and accuracy
Implementation Method 3
a multiplexer for coupling or combining or superposing the at least first light beam and the at least second light beam in a common measurement beam
Implementation Method 4
at least one first light source for producing at least one first monochromatic light beam, capable of interference, with a first wavelength
Data Source
AI summary
A distance measuring arrangement for determining a distance from an object includes at least one light source for producing at least one first monochromatic and interference-capable light beam with a first wavelength and at least one second monochromatic and interference-capable light beam with a second wavelength, a multiplexer for coupling or combining the at least one first light beam and the at least one second light beam into a common measurement beam, an output coupling element for splitting the measurement beam into a reference beam and a signal beam, wherein the reference beam propagates along a reference path and wherein the signal beam propagates along a signal path, and a phase modulator that is arranged in the signal path and configured to modulate the phase of the signal beam periodically in time.