Chromatically dispersed interferometry with wavelet analysis.
A new white-light interferometry point sensor utilizing a chromatically dispersed depth detection field is addressed. Monitoring the interference in the optical frequency domain allows for microscopic height detection without the necessity of a mechanical axial scan. The problem of limited dynamic range in previously reported spectral interferometric schemes is solved by forming a high-contrast interference window due to the chromatically dispersed focusing of the detection field. In a proof-of-principle experiment, the position of a reflecting object could be retrieved with a focus of 0.8 NA over an axial range of 30 microm by analyzing the phase of the emerging interference wavelets.
Papastathopoulos
Evangelos
E
Institut für Technische Optik, Universität Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany. papastav@ito-uni-stuttgart.de
Körner
Klaus
K
Osten
Wolfgang
W