Start typing and press Enter to search

This website does not support Internet Explorer. For a correct visualization we recommend to use Microsoft Edge or Google Chrome.

logo_i

Sensofar Interferometry

Interferometry has been developed to measure the surface height of very smooth to moderately rough surfaces, achieving same system noise at any magnification. For PSI, it can achieve system noise better than 0.01 nm.

BACKGROUND

Interferometry working principle

The working principle of Interferometry technology consists on a splitting of the light into two beams that travel different optical paths and are then combined to produce interference. Interferometric objectives allow the microscope to operate as interferometer; fringes are observed in the sample when it is in focus.

Background Interferometry
Background Interferometry
Background Interferometry
PSI measurement

PHASE SHIFTING INTERFEROMETRY (PSI)
Uses narrowband light source (red, green, or blue) to measure the phase of the interferogram. It can achieve better than 0.01 nm system noise.

PHASE SHIFTING INTERFEROMETRY (PSI)
Uses narrowband light source (red, green, or blue) to measure the phase of the interferogram. It can achieve better than 0.01 nm system noise.

CSI measurement

COHERENCE SCANNING INTERFEROMETRY (CSI)
Uses broadband light source (white light) to get a narrow interferogram. Height is determined by the location of the maximum signal of the envelope of the interference signal.

COHERENCE SCANNING INTERFEROMETRY (CSI)
Uses broadband light source (white light) to get a narrow interferogram. Height is determined by the location of the maximum signal of the envelope of the interference signal.

OPTICAL SCHEME

The optical scheme for PSI is the same configuration than FV but now using an interferometric objective instead of bright field. To obtain a topography the sensorhead is scanned along the Z direction. For PSI, few microns are scanned and the phase is retrieved. For CSI, as many microns are scanned as required to scan the full surface.

PSI
PSI Optical Scheme

Phase Shift Interferometry (PSI) has been developed to measure the surface height of very smooth and continuous surfaces with sub-Angstrom resolution, for all numerical apertures (NA). Very low magnifications (2.5X) can be employed to measure large fields of view with the same height resolution.

S neox PSI Configuration
CSI
CSI Optical Scheme

Coherence Scanning Interferometry (CSI) uses white light to scan the surface height of smooth to moderately rough surfaces, achieving 1 nm height resolution at any magnification.
Read one of our related papers

S neox CSI Configuration

PROPRIETARY ALGORITHMS

With Interferometry, the 3D measurement is performed with the maximum accuracy. It is possible to scan along the z axis to obtain fringes on the complete sample, obtaining height information from the intensity or the phase of the interferogram for PSI or CSI, respectively and reconstruct the 3D image with the obtained heights for the different pixels.

Interferometry Topography
Banner Webinar Interferometry
k.features_i

KEY FEATURES

  Large FOVs with nanometer system noise no matter the objective  

  PSI: 0.01 nm system noise 

  Thickness measurements from 1.5 μm to 100 μm 

logo_i

Interferometry systems

portfolio_sneox
portfolio_fiveaxis
portfolio_slynx
Sensors and integrable solutions