Technology

The broad-band light received after reflection is first optically encoded by the sensor head according to the distance of the point on the object or the layer thickness. This signal information is fed to the control unit via the same optical fiber light guide as was used to illuminate the object. Here the signal information is combined by means of patented SCI (“Spectral Coherence Interferometry”) technology to signal intensity per distance. After opto-electronic conversion in the DSP (“Digital Signal Processor”) the appropriate information is available for external units. Extremely fast sequential variation of optical filter parameters in the SCI unit thus enables acquisition of a depth scan (tomogram) or layer information or of a surface height profile (topogram) at rates of up to 4 kHz.

The advantage of this technology lies in the straightforward combination of two different optical wavelengths (1300 nm and 830 nm) without requiring more space within the control unit. Up to 4 channels can be operated at 1300 nm or 830 nm or in combination.
 

The broad-band light received after reflection is first optically encoded by the sensor head according to the distance of the point on the object or the layer thickness. This signal information is fed to the control unit via the same optical fiber light guide as was used to illuminate the object. In the control unit the signal information is spectrally resolved scanned in parallel with a multipoint sensor. Subsequent high speed processing in an FPGA (“Field Programmable Gate Array”) enable acquisition of a depth scan (tomogram) or layer information or of a surface height profile (topogram) at rates of up to 16 kHz. The technology is currently limited to use of light of 830 nm wavelength.

The advantage of this technology lies in the combination of extremely high precision and acquisition rate. Here too 4 channels can be operated without loss of speed.