Waveguide Materials

Plasma Quest Ltd can deposit high-quality planar optical waveguide materials utilising our proprietary thin film sputter deposition equipment.  Planar waveguides are often fabricated in the form of a central core sandwiched between two layers that possess a refractive index lower than the core.  The two outer layers need not be identical and therefore air can sometimes be utilised as the top layer.

A wide range of dielectric films can be reactively sputtered at high rates for use as a waveguide material.  Imperfections in the thin film waveguide material can cause absorption, radiation and scattering resulting in beam propagation loss.  PQL’s differentiator is the independent control of the plasma ion density and the ion energy enabling an unparalleled range of deposition variables.  This enables the deposition of high-quality thin films which are

  • smooth
  • uniform
  • stress controlled
  • have very little argon inclusion (<1%)
  • refractive indices close to bulk

In addition the HiTUS technology also has the ability to control the growth mechanism of the material, ranging from amorphous to crystalline and also directing the preferred crystalline direction.

Dielectric waveguide materials include Ta2O5, Al2O3 and Y2O3.  PQL has deposited high-quality waveguiding alumina layers that appeared to be unaffected by ultraviolet irradiation – a requirement for the “next generation” of upconversion lasers using thulium as the active laser ion.

If a material can be sputter deposited, it can be coated using the Plasma Quest approach. Please Contact Us for a discussion about how our coating service can solve your problems. We look forward to speaking with you.


If you would like to discuss your trial requirements, obtain costing, turnaround times, or for any other questions, we would love to hear from you.