We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Wavemeter?

By Angie Bates
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A wavemeter is a device used in fiber optics to measure the wavelength of laser beams. Also called a wavelength meter, a wavemeter tests the optical elements of products as they are being manufactured. Wavemeters are used when extremely precise measurements are necessary.

Wavemeters are interferometers used only for measuring wavelengths. Interferometers measure light waves by using interference, usually provided by mirrors, to split a light beam in two and then recombine it. By studying the resulting shape, measurements of the beam can be taken.

There are two main types of wavemeters: scanning and static. The first type is usually based on the Scanning Michelson Interferometer. These types of wavemeters consist of three mirrors, a light source, and a detector. Resembling a cross-shape, each piece of the Michelson Interferometer is located on one corner of the cross. The light source is positioned opposite one of the mirrors, and a second mirror and the detector are placed perpendicular to them. The third mirror, half-silvered, is positioned at an angle in the center. This is the mirror that actually splits the beam.

When the light source is activated, the laser will hit the half-silvered mirror and split, one half of the beam going straight through, and the other half moving perpendicular to the first. Both halves will hit the positioned mirrors behind and above the center mirror, rebound, and be recombined by the half-silvered mirror. The recombined beam will then move straight down into the detector, which will analyze the results.

The distance between the mirrors, or arms, can be changed to scan a range of lengths. The accuracy of these wavemeters can be as great as 0.01 nm. Several issues, however, such as imperfections in the beam, length drifts, and fluctuations in input power, could give less accurate results.

Most static wavemeters are based on the Static Fizeau Interferometer. These wavemeters do not have moving parts, but use the same principle of mirrored reflection. Less common static wavemeters are based on Fabry-Pérot interferometers, which are linear. These are more often used as optical spectrometers than wavemeters, however.

High accuracy for any type of wavemeter depends on the stability of the setup and the resolution of the display. A reference laser, whose wavelength is known, working in tandem with the laser being tested will also help to increase accuracy. In cases where extreme accuracy is vital, calibrating the machine as much as once a minute may be necessary.

Wavelengths can also be measured with spectrometers, but although spectrometers give more information about the components of the light beam, precision is sacrificed. Some types of wavemeters can also function as spectrometers, thus giving additional information without sacrificing accuracy.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By anon168679 — On Apr 18, 2011

how much are these worth?

By anon167050 — On Apr 11, 2011

General Radio manufactured the 754-A Wavemeter in the 1940's with a frequency range of 220MHz to 1000MHz.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.