Plane polarized beam is not welcomed in some circumstances such as reflecting spectrometer. A depolarizer will change the plane polarization into a mix of polarization states by scrambling up the polarization, the result is to change plane polarized beam into pseudo-depolarized beam and produce depolarization. Depolarizer is widely used in polarization sensitive instrument.
Farview Optics' quartz wedge depolarizer consists of two 3deg wedges of crystal quartz. Usual wedge depolarizer consists of one crystal quartz wedge and a compensation fused silica to avoid big beam deviation, but the deviation is also very big for some precise instruments. Farview Optics does not use fused silica plate to compensate the beam deviation, we use a crystal quartz plate with its optical axis along the propagation direction. Because the depolarizer is constructed by same material, so the beam deviation can be much better. The usual depolarizer can only be used at narrow band wavelength to avoid the big beam deviation. With our special design, our depolarizer can be used in a wide range of wavelength and keep the beam deviation in an acceptable range.
When a beam hits on the depolarizer, there is a variable phase shift across the beam aperture on the wedge, so a polarized beam can be effectively depolarized. Quartz wedge depolarizer can work well with monochromatic and broadband light source.Usually we can get better result if we orient the input polarization state 45deg to the optical axis of the depolarizer. And also the effectiveness of the depolarizer increases with the size of the beam cross-section.
Better At 45deg Optical Axis Alignment
Ideal for >6mm Diameter Monochromatic Light & Broadband Light
Epoxy Cemented or Optically Contacted Available
Dimension Tolerance +0/-0.2mm
Thickness Tolerance ±0.2mm
Surface Quality 60/40
Parallelism <1 arc minute
Beam Deviation <3 arc minutes
Retardation 0.5λ/mm at 1064nm
Clear Aperture >90% central
Damage Threshold Cemented: >500mJ/cm2, 20ns, 20Hz @1064nm
Optically contacted: >5J/cm2, 20ns, 20Hz @1064nm