Laser interferometry

Fizeau laser interferometry is a highly precise and powerful measurement technique used in a variety of fields such as metrology, engineering, and materials science. It is named after Armand Fizeau, a French physicist who first developed the principle of interference in the 19th century.

In Fizeau laser interferometry, a laser beam is split into two parts. One part is directed towards the object being measured, while the other part is directed towards a reference mirror. The light waves from both paths are then recombined and interference patterns are observed and analyzed to determine the surface profile of the object.

The process of recombining the light waves results in either constructive or destructive interference, depending on the path length difference between the two beams. By measuring the intensity of the resulting interference pattern, it is possible to determine the surface profile of the object being measured.

Fizeau laser interferometry has a number of advantages over other measurement techniques. For example, it is non-contact, which means that the object being measured is not touched or disturbed in any way during the measurement process. In addition, Fizeau laser interferometry is extremely precise, capable of measuring surface profiles to within a few nanometers. This level of accuracy makes it an essential tool in many industries, including semiconductor manufacturing, aerospace engineering, and optics production.

Fizeau laser interferometry is also highly adaptable and can be used to measure a variety of surface profiles. For example, it can be used to measure the flatness of semiconductor wafers, the surface roughness of metal components, and the curvature of lenses and mirrors.

Ametek-Zygo Fizeau interferometers

At our laboraoty we are proud users of a Zygo HDX interferometer. Among the most common applications of this tool it is worth to recall:

1. The measurement of surface profile and roughness. Optical components such as lenses, mirrors, and prisms must meet strict surface quality requirements to ensure optimal performance in our experiments. Laser interferometry allows us to precisely measure the surface profile and roughness of these components, enabling them to ensure that they meet our requirements.

2. Another important application of laser interferometry is in the measurement of form errors. Optical components must have precise shapes to function correctly, and form errors can lead to poor performance. Laser interferometry can be used to measure form errors, i.e. the difference between the expected shape of a surface and the real shape wish sub-nm accuracy.

3. Laser interferometry is also used in the measurement of surface defects. Even small defects such as scratches, pits, and bubbles can affect the performance of optical components. Laser interferometry allows us to precisely measure the size and location of these defects, enabling to take corrective action or reject defective samples.

4. One key application of laser interferometry is in the measurement of mechanical components. This includes the measurement of shape and deformation, which are critical parameters in the design and testing of crystals and other mechanical systems. Laser interferometry is used to precisely measure these parameters and provide detailed information about the behavior and performance of mechanical components under different operating conditions.

Conclusion

We have explored the basics of laser interferometry for precision engineering, showing how this method utilizes interference patterns to measure objects accurately. This cutting-edge technology is being used by engineers and manufacturers around the world to create more complex parts with greater accuracy than ever before. With its ability to produce accurate measurements quickly, laser interferometry has become an invaluable tool in modern manufacturing processes - allowing businesses and research to reach cutting-edge results.