Si Phase Retarders
Phase retarder components are used in laser systems to convert a linearly polarized beam into a
circularly polarized beam.
In order to convert linear into circular polarization a total of one-quarter wave, or λ/4 retardation
(90°) is required. This may be achieved using a single λ/4 retarder, or by a combination of two λ/8
Si phase retarders are available in both λ/4 and λ/8 types, see tables 12.101 and 12.102.
Diameter : +0 / -0.1mm
Thickness: : ± 0.1mm
Flatness : λ/40 over any 25mm dia test area
Reflectivity : > 98.5%
Wavelength range : 10.6μm only
Phase retardation (a) λ/8 type .. 45° +/- 4°
(b) λ/4 type .. 90° +/- 6°
LIDT (normal inc.) : > 250W/mm