Related Experiment Video
Updated: Jun 13, 2026

Implementation of a Reference Interferometer for Nanodetection
Published on: April 26, 2014
Absolute distance measurement by wavelength shift interferometry with a laser diode: some systematic error sources
Abstract:
A method for measuring absolute distance by the wavelength shift of laser diode light has previously been proposed. In this work three serious systematic error sources for the method are discussed and some of the discussion is confirmed by experiment. The error sources are optical feedback effect, longitudinal mode distribution of laser light, and unwanted light reflected from optical devices (coherent noise). The optical feedback effect influences the wavelength shift of the emitted light. The mode distribution causes the periodic error dependent on the measured distance, and the maximum error is determined by the change in the intensity ratio of the submodes to the main mode. Coherent noise causes the periodic error also dependent on the distance, and the maximum error is determined by the amplitude ratio of the measuring lightwave to the noise. These systematic errors are observed in some demonstrative experiments.
Related Concept Videos
Electronic Distance Measuring Instruments
Distance Corrections
Uncertainty in Measurement: Reading Instruments
Atomic Absorption Spectroscopy: Interference
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
Random and Systematic Errors
Uncertainty in Measurement: Accuracy and Precision

