THz Waveplates

Download THz Waveplates Datasheet (PDF, 106 KB)

Polarimetry technique is very important for analyzing the THz radiations (divergence, spatial or frequency modes, and profiles). The key instrument in polarimetry is polarization modulator which identifies and measures polarized signal.

Plano-plano plates, made of birefringent material, are used for modifying polarization state of radiation. A waveplate works by shifting the phase between two perpendicular polarization components of the wave. The most common types of waveplates are a half-wave plate (λ/2 plate) and a quarter-wave plate (λ/4 plate). λ/2 plate gives phase delay π and λ/4 plate — π/2. A half-wave plate changes the polarization direction of linear polarized light. A quarter-wave plate changes linearly polarized light to circular and vice versa. Waveplate will not change the polarization of linearly polarized beam if the polarization direction is along one of waveplate axes.

Operating principle of Half-wave plate

Half-wave plate

Operating principle of Quarter-wave plate

Quarter-wave plate

Tydex offers the THz waveplates for single operation wavelength: 


Common specification:

Retardation type, λ ½, ¼
Operation wavelength range, μm 40-1000
Material THz grade crystalquartz
Orientation X-cut
Orientation tolerance, arc. min. ±10
Standard dimensions, mm 20×20, 50×50
Maximal dimensions, mm 60×60
Dimensions tolerance, mm ±0.25
Thickness tolerance, µm ±5.0
Clear aperture, % ≥90
Parallelism, arc. min. 5
Surface quality, scr/dig 60/40
TWD, λ@633nm ½

Please check our Optics stock.
Alternate sizes and custom design are available upon request. 
For price quotation and delivery please fill in our Request form.

Segmented waveplate consisting of several specially oriented half-wave plates allows getting radiation with radial and azimuthal polarization from linearly polarized one. Operating principle of such waveplates is shown below.

THz Segmented Waveplates
Operating principle of segmented waveplates:

THz Segmented Waveplates

THz Segmented Waveplate Operation Principle

Radial polarization can be changed to azimuthal one by rotating segmented waveplate at 45 degrees. Direction of radial polarization becomes the opposite one by rotating the waveplate at 90 degrees. Combination of segmented waveplate with positive lens gives radiation polarized along to its propagation direction.

Segmented waveplates are manufactured upon request.

For price quotation and delivery please fill in our Request form.