Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Common Leveling Mistakes and Errors

Common Leveling Mistakes and Errors

A survey team is tasked with determining the elevation difference between points Point A and Point B, separated by uneven terrain. They use a leveling instrument and a leveling rod.Common MistakesMisreading the Rod: During a backsight reading at Point A, the instrumentman observes the rod partially obscured by tall grass. Instead of reading 1.135 m, they mistakenly record 1.735 m due to the misalignment of the crosshair with the wrong graduation. This error adds 0.600 m to all subsequent...

Errors in Global Positioning System

Errors in Global Positioning System

Global Positioning System (GPS) technology has revolutionized navigation and positioning, but its accuracy is often compromised by various errors. These errors, stemming from environmental, satellite, and receiver-related factors, require careful mitigation to ensure reliable performance across applications.Atmospheric ErrorsGPS signals travel through the Earth’s ionosphere and troposphere, introducing delays which affect accuracy. The ionosphere is strongly influenced by charged particles,...

Uncertainty in Measurement: Accuracy and Precision

Uncertainty in Measurement: Accuracy and Precision

Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.

$Influence of Earth's Curvature and Atmospheric Refraction on Leveling$ 01:26

Influence of Earth's Curvature and Atmospheric Refraction on Leveling

During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...

Random and Systematic Errors

Random and Systematic Errors

Scientists always try their best to record measurements with the utmost accuracy and precision. However, sometimes errors do occur. These errors can be random or systematic. Random errors are observed due to the inconsistency or fluctuation in the measurement process, or variations in the quantity itself that is being measured. Such errors fluctuate from being greater than or less than the true value in repeated measurements. Consider a scientist measuring the length of an earthworm using a...

Random and Systematic Errors

Random and Systematic Errors

Scientists always try their best to record measurements with the utmost accuracy and precision. However, sometimes errors do occur. These errors can be random or systematic. Random errors are observed due to the inconsistency or fluctuation in the measurement process, or variations in the quantity itself that is being measured. Such errors fluctuate from being greater than or less than the true value in repeated measurements. Consider a scientist measuring the length of an earthworm using a...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Scanning differential interferometer to measure index heterogeneity.

Applied optics·2010

Same author

Evaluation of highly corrected optics by measurement of the Strehl ratio.

Applied optics·2010

See all related articles

Search research articles

Related Experiment Video

Updated: Jun 12, 2026

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

Published on: August 12, 2013

Residual errors in laser interferometry from air turbulence and nonlinearity.

|May 22, 2010

Summary

Airflow in semiconductor manufacturing can degrade laser displacement interferometry accuracy through optical path length fluctuations. However, periodic nonlinearity in the beamsplitter presents a more fundamental limit to heterodyne interferometer precision.

Area of Science:

Metrology
Optical Engineering
Semiconductor Manufacturing

Background:

Laser displacement interferometry is crucial for precision semiconductor manufacturing.
High-velocity airflow is used to reduce airborne contaminants but can degrade interferometer performance.
Fluctuations in the refractive index caused by airflow impact measurement accuracy.

Purpose of the Study:

To quantify optical path length (OPL) fluctuations due to airflow in interferometric systems.
To assess the impact of these fluctuations on measurement accuracy.
To investigate a fundamental nonlinearity limit in heterodyne interferometers.

Main Methods:

Measurement of OPL fluctuation magnitude, correlation length, and probability distribution under various airflow conditions.

More Related Videos

Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

Published on: February 27, 2013

Bringing the Visible Universe into Focus with Robo-AO

Bringing the Visible Universe into Focus with Robo-AO

Published on: February 12, 2013

Related Experiment Videos

Last Updated: Jun 12, 2026

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

Published on: August 12, 2013

Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

Published on: February 27, 2013

Bringing the Visible Universe into Focus with Robo-AO

Bringing the Visible Universe into Focus with Robo-AO

Published on: February 12, 2013

Analysis of path length errors for common interferometric configurations.

Detailed investigation and direct observation of beamsplitter nonlinearity in heterodyne Michelson interferometers.

Main Results:

OPL fluctuations caused by airflow are generally less significant than other systematic errors.
A periodic nonlinearity in the beamsplitter was identified as a fundamental accuracy limitation.
The observed nonlinearity magnitude was approximately lambda/64 for the tested beam splitters.

Conclusions:

While airflow-induced OPL fluctuations affect precision, they are often secondary to other error sources.
Beamsplitter nonlinearity represents a more critical factor limiting heterodyne interferometer accuracy.
A technique for detecting and quantifying this nonlinearity has been developed.