Thin Film Polarizers

Thin film polarizers (TFP) are used to separate the polarization directions of light (s- and p-polarization). If the TFP is installed under the Brewster angle (material-dependent), complete cancellation of the p-polarized component is achieved.

LAYERTEC produces thin film polarizers on flat substrates for wavelengths between 260 nm and 2500 nm. In contrast to polarization beam splitter cubes, they have high laser damage thresholds and are therefore optimally suited for use in high-power lasers.

TFPs are manufactured for angles of incidence > 40°. At the Brewster angle, they have a much wider bandwidth and higher Ts/Tp ratio. Typical polarization ratios are Ts/Tp > 500 for AOI = 45° or 55°. An extended wavelength range with limited polarization ratio can be achieved by choosing incidence angles beyond the Brewster angle.

  Reflection on a plane surface of s- and p-polarized light

  Brewster's angle

  Rs, Rp and Ru for FS with n = 1,45; unpol = unpolarized = (s+p)/2