Testing Capabilities

Optical Interferometry / Profilometry

Optical Interferometry is a technique of combining light from multiple sources in an optical instrument in order to make various precise measurements.  This technique has been applied to characterize surface topography, surface profile, and surface roughness.

ITL offers accurate surface texture characterization with the WYKO RST Plus surface profiling system.  The RST Plus is a non-contact optical profiler that uses two technologies to measure a wide range of surface parameters.  Phase-shifting interferometry (PSI) mode allows to measure smooth surfaces at the Angstrom level, while vertical-scaning interferometry (VSI) mode allows to measure rough surfaces and steps at the nanometer level up to the micrometer level.  The RST Plus yields 3D and 2D surface profiles over an area as opposed to the stylus type profilers that only gives roughness over a single line. 


The optical interferometer is an excellent metrology instrument for obtaining surface roughness and texture data on:

• Precision machined surfaces
• Integrated optical circuits
• Waveguides
• Optics and fibers
• Ceramics
• Thin-films
• MEMS devices
• And numerous other industrial measurements

Surface Measurement Parameters offered by the optical profiler:

Ra – Roughness Average
Rq - Root Mean Square (rms) Roughness
Rp,Rv – Maximum profile peak height, Maximum profile valley depth
Rz – Average maximum height of the profile
Rt, Rsk, Rku, Pc, and more