Tech FAQ

Frequently Asked Questions

The polarization direction is marked on all mounted and unmounted polarizers we sell. For a more precise determination, use a laser line beamsplitting polarizer. The transmitted linear polarization direction lies precisely in the plane defined by the incident and reflected laser beams.

Dual wavelength retarders are primarily for use at two different wavelengths separated by 20% apart. If the wavelengths are both covered by one of our standard achromatic retarder wavelength ranges, we recommend purchasing a Precision Achromatic Retarder. We can also do custom achromatic retarder wavelength ranges. Please contact your Meadowlark Optics sales engineer for assistance and a custom quote.

If the wavelength difference between the two is greater than 30 to 35% of the lower wavelength, then we recommend a Dual Wavelength Retarder. Please contact your Meadowlark Optics sales engineer for assistance so that we can design for you the required Dual Wavelength Retarder or if you need any help at all.

While not all retardance and wavelength combinations are available, we can manufacture tens of thousands of different combinations for our Dual Wavelength Retarders. Please contact your Meadowlark Optics sales engineer for assistance and a custom quote.
This is a common misconception. In fact, compound zero-order retarders are twice as bad as the multi-order retarders they are made from! If you need a good field of view, you must use a true zero-order retarder. See our Application Note.
0.5 nanometers exceeds even our tight tolerance on retardance! Try angle tuning your retarder. A 10° tilt can change the retardance by about 1.25 nm or 0.002 waves of retardance at 632.8. Remember to tilt about the fast or slow axis of your retarder, likely at ±45° to your optical bench. See our Application Note about retarders. Another solution is to use a liquid crystal variable retarder,