Meaning
Optical surface profiling techniques that introduce a high-density tilt fringe pattern across an interference field extract three-dimensional surface height maps from a single camera frame. Applying spatial carrier interferometry allows high-speed non-contact topography measurement of moving polymer films, optical lenses, or vibration-sensitive injection mould inserts. Fourier transform algorithms process spatial carrier frequency shifts caused by surface height variations without requiring temporal phase shifting.
Single-exposure capture eliminates measurement sensitivity to environmental shop-floor vibrations.
Fourier Transform
Frequency-domain signal processing isolates spatial carrier frequencies from low-frequency intensity variations and high-frequency optical noise. Utilizing spatial carrier interferometry enables automated digital filtering of phase maps in spatial frequency space. Inverse Fourier transforms reconstruct continuous three-dimensional surface profiles from bandpass filtered spectra.
Digital filtering yields clean surface height topographies.
Single Frame
Rapid image capture records complete optical phase information within a single camera exposure time. Systems employing spatial carrier interferometry capture high-speed surface topographies on fast-moving continuous polymer extrusions. Short exposure times freeze mechanical vibration during part movement.
High-speed cameras enable in-line automated quality inspection.
Carrier Frequency
Tilting reference mirrors introduces a dense pattern of straight parallel interference fringes across the field of view. Optimizing carrier frequency settings in spatial carrier interferometry balances spatial height resolution against maximum measurable surface slope limits. Insufficient carrier tilt causes frequency overlap in spatial spectra.
High carrier frequencies maximize surface feature resolution.
