This technique consists of measuring the angles at which a prism will couple light from a laser beam into the sample film. The thickness and refractive index of the film are calculated from the measured angles. This instrument can masure bulk material, as well as single and dual layer films. The prism is in direct contact with the sample.

Available lasers

632.8 nm He-Ne laser.

1550.0 nm laser diode.

Refractive-index range

With a GGG prism (n=1.965 at 632.8 nm) it covers 1.0–1.8.

With a Rutile prism (n=2.865 at 632.8 nm) it covers 1.8–2.45.

Polarization

TE mode.

Film thickness range

0.4 µm–20 µm with ±0.5% accuracy and ±0.01 µm resolution.