Low Coherence, Spectrally Modulated, Spherical Wavefront Probe for Nanometer Level Free-Form Metrology

To-date free-form optic manufacture is limited due to inadequate metrology to measure surfaces with free-form and conformal shapes, with large surface slopes and to the required measurement uncertainty. In this proposal we describe a new interferometric non-contact probe capable of measuring free-form optics with nanometer sensitivity. The probe has favorable metrology characteristics and uses a new interferometric modality allowing the advantages of low-coherence interferometry in common path interferometer designs. The combination of high acceptance angles and high sensitivity make possible the use of a simple three-orthogonal-axis metrology frame and fulfills the precision requirements demanded by NASA and industry. The projected data acquisition rates in excess of 10?kHz will provide an attractive manufacturing metrology tool.