Laser Interferometer Disturbance Correction Using a Vibration Element
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser vibrometers face challenges in reducing the influence of disturbances from building or facility vibrations while maintaining a small size, as attaching a contact type vibrometer increases the overall size and compromises measurement accuracy.
Innovation Solution
A laser interferometer design incorporating a vibration element in the optical modulator to modulate laser light, a light receiving element to detect reflected signals, a demodulation circuit to process these signals, and a correction circuit to account for disturbances, using a compact laser light source and vibration element to enhance measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a contact type vibrometer is attached to measure structure vibration, then measurement accuracy of object vibration is improved, but device size increases
Solution Approach 1:
The patent combines the vibration measurement function and the disturbance measurement function into a single laser interferometer device. The optical modulator with vibration element serves dual purposes: modulating the reference light and detecting structure vibrations through frequency shifts, eliminating the need for separate contact and non-contact vibrometers
Solution Approach 2:
The laser interferometer is designed to perform multiple functions: measuring object vibration speed non-contactly and simultaneously measuring structure vibration for disturbance compensation. The vibration element in the optical modulator acts as both a modulation component and a disturbance sensor
2Device complexity
If building or facility vibration disturbance is not corrected, then device complexity is reduced, but measurement precision of object vibration deteriorates
Solution Approach 1:
The patent implements feedback by using the measured structure vibration to correct the object vibration measurement. The correction circuit uses the frequency shift information from the vibration element to compensate for disturbance effects on the measurement results
Solution Approach 2:
The vibration element in the optical modulator serves as an intermediary that detects structure vibrations and provides correction information. By measuring the frequency shift of the reference light caused by structure vibration, the system obtains disturbance information needed for correction
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 design allows for accurate measurement of object displacement and speed by minimizing disturbance influence, achieving high measurement accuracy and reducing the size of the laser interferometer.
Implementation Method 1
an optical modulator including a vibration element and configured to modulate the first laser light using the vibration element and generate second laser light including a modulation signal
Implementation Method 2
a light receiving element configured to receive third laser light including a sample signal generated by the first laser light being reflected by an object
Implementation Method 3
a correction circuit configured to detect a force acting on the vibration element from a change in vibration of the vibration element
Data Source
AI summary
A laser interferometer includes: a laser light source configured to emit first laser light; an optical modulator including a vibration element and configured to modulate the first laser light using the vibration element and generate second laser light including a modulation signal; a light receiving element configured to receive third laser light including a sample signal generated by the first laser light being reflected by an object and the second laser light, and output a light reception signal; a demodulation circuit configured to demodulate the sample signal from the light reception signal; and a correction circuit configured to detect a force acting on the vibration element from a change in vibration of the vibration element and correct the light reception signal based on the force.