Thin film polarizers (TFP)
Sizes up to Ø200 mm | Extinction ratio >1000:1
Thin film polarizers (TFP) can be a solution for many applications in optical devices and systems. For example, it can serve as an alternative for Glan type polarizers in laser systems, when a filtering of light source is needed.
Polarizers are used to efficiently separate s- and p- polarization beams. Due to interference, s- and p- polarizations are separated by 90 degrees, where p- polarization is almost fully transmitted through the optical element while s- polarization is reflected, hence the name polarizing beamsplitter.
3photon offers high contrast TFP plates: glass plates (usually high quality UVFS Corning 7980 0F substrates) with dielectric polarizing coating.
TFP plates are often designed to perform best at Brewster‘s angle. At this angle, the s- polarization beam is almost fully reflected from the surface while p- polarization travels through the element. This way the reflection losses are avoided for the transmitted polarization and does not require to have an anti-reflection (AR) backside coating for the p-polarization on the back surface. However, polarizer coating can be designed to perform on other angle of incidences as well.
- Typical specifications
Applications depends on what angle of incidence the TFP plate is being used:
- At AOI=45°, TFP plates are used as a polarizing beam-splitter which separates p- and s- polarizations by 90° or a beam combiner for different polarizations at the same wavelengths.
- At AOI=56.6° (Brewster ‘s angle), TFP plates are used as an alternative to Glan laser polarizing prisms or polarizing cube beam-splitters in Nd:YAG and Nd:YVO4 or other laser systems;
- At AOI=72°, TFP plates are used as broadband polarization separators that achieve low dispersion in femtosecond laser systems and other high power laser applications.
Other applications include:
- SHG generation.
- Laser materials processing.
- Highly efficient at Brewster ‘s angle.
- Less expensive to manufacture when compared to the polarizing cubes & larger variation of sizes and apertures.
- Typically, higher laser damage threshold than PBS cubes.
- Low wavefront distortion.
- Standard wavelengths:
- 532 nm Tp > 99%, Rs > 99.8%, AOI = Brewsters;
- 633 nm Tp > 99.3%, Rs > 99.8%, AOI = Brewsters;
- 1064 nm Tp > 99.6%, Rs > 99.9%, AOI = Brewsters;
- Extinction ratio Tp/Ts > 1000:1;
- Custom coating for a variety of angle of incidences and wavelengths is available.