Rarely are errors due to the interferometer itself considered when measuring optics with a laser Fizeau interferometer. Piotr gives examples of common and significant errors generated in the interferometer. Click to download his presentation with notes here.
Below is just an example of the error sources explored in Piotr’s presentation
This month (November 2016) Laser Focus World published our paper “Three Simple Tests to Assess Interferometer Performance“. Let us know what you think.
Also get Äpre’s test target that is required to assess the imaging performance of your interferometer.
Shown here is a Generation II interferometer (ground glass disk with continuous zoom system) that exhibits significant retrace error with tilt.
ÄPRE is offering a free interferometer image resolution test target. The target is simple to use without requiring complicated and expensive phase stepped optics. Simply place the 1-cycle/mm test target in front of your interferometer and look at its image on your camera. If you cannot see these lines, you cannot measure surfaces to these fine of details. Also if a zoom system is present you can zoom in and see if the resolution improves, stays the same or degrades.
Send us your contact information including your email address and mail delivery address and we will mail you a target.
Here is shown a Generation II interferometer (Ground Glass with Continuous Zoom Imaging System) demonstrating lost resolution at the edges of the field.
