Ta2O5 | Optical characterization of thin films

Ta2O5(Tantalum pentoxide) is a high-index material (nearly 2.16 at 550 nm), with a transmittance range from below 0.3 μm to nearly 10 μm. The high durability and stability to heat allows this material to be use in telecommunication components such as those for dense wave division multiplexing (DWDM), which usually have more than 100 layers.

Ta2O5 is also known to have a high laser-induced damaged threshold (LIDT) toward ND:YAG and other near-IR lasers. Research has revealed that AR coatings deposited using ion-assisted deposition (IAD) have good environmental stability and no spectral shift, even at high temperature and humidity, given that the exposure of Ta2O5 to high temperatures converts it into its crystalline form. Ta2O5 is one of the most suitable materials for IAD, producing thin films with no shifting in their optical constants. This is why Ta2O plays an important role as an alternative to TiO2 thin films. When using IAD, the film structure of Ta2O5 tends to be amorphous.

In addition, Ta2O5 is of particular interest because of its excellent UV and VIS transparency, as well as its superior durability and resistance to chemical attack.