Optical properties of bismuth trifluoride thin films

Area of Science:

• Materials Science
• Optics
• Thin Film Technology

Background:

• Optical thin films are crucial for various photonic applications.
• Bismuth trifluoride (BiF(3)) is explored as a potential material for optical coatings.

Purpose of the Study:

• To investigate the optical properties of BiF(3) thin films.
• To assess the feasibility of BiF(3) as a new optical thin film coating.

Main Methods:

• Deposition of BiF(3) films on KCl substrates up to 2.35 microm thickness.
• Preparation methods included thermal evaporation and reactive sputtering in a Freon atmosphere.
• Optical properties were measured, along with far infrared and Auger spectra.

Main Results:

• Similar optical properties were achieved using both deposition techniques.
• A very broad transmission range from 2600 Angstroms to 20 micrometers was measured for ~1 micrometer thick BiF(3) films.
• Far IR and Auger spectra provided further material characterization.

Conclusions:

• BiF(3) thin films demonstrate a wide transmission spectrum.
• BiF(3) shows potential as an optical thin film coating for applications not requiring high power handling at 10.6 micrometers and longer wavelengths.