UFI white light interferometer
White light interferometer --- second-order dispersion measurement
Ultrafast laser requires good control of the dispersion introduced by the coating for its optical components, especially reflective optical components. However, in practical applications, due to inevitable manufacturing errors, the actual results will definitely deviate from the theoretical design. GD and GDD are very sensitive to the thickness of the coating, even if the most advanced coating is used Technology and errors cannot be completely eliminated, so the accurate measurement of GD and GDD of optical components plays a vital role. The GOBI series white light interferometer from Ultrafast Innovations in Germany uses spectral resolution interferometry for precise measurement to help users obtain accurate second-order dispersion curves.
Technical features:
▪ Optional bands: 400-1060nm, 250-1060nm and 900-2400nm;
▪ No reference laser and specified reflectivity required
▪ Both S and P polarization can be measured separately
▪ Powerful data processing software
▪ Measurement results are highly consistent with theoretical calculations ▪ Fast and simple working process
Comparison of GDD measured by GOBI and theoretical design. (a) Unique dual-angle design ultra-wideband PC70 (chirped mirror produced by UFI), measurement of 5° and 19° normal incident angles, and average results. (b) Test results of infrared pulse compression mirror PC1921. (c) Results for high dispersion HD73 mirror (-3000 fs2 change at 1030 nm).
Compared with other devices, GOBI white light interferometer is able to measure strong GDD oscillations. It is worth noting that the difference between the measured curve and the theoretical curve in the example image reflects the tolerances in the manufacturing process of the optical element film layer.
GD(a) and GDD(b) are a comparison of the actual measured reflectance of the UV beam on the mirror (green curve) and the corresponding theoretical prediction (red line).
Comparison of actual measurement (green) and theoretical data (red) of GD (c) and GDD (d) of an ultra-broadband 96-layer dispersion compensation mirror.