Chromatic Interferometric Probe

The OptiPro Nanometric Probe is a spectral chromatic interferometer that can measure the displacement to a surface, such as an astronomical telescope mirror, with outstanding performance.nbsp; Indeed, in Phase I we designed and built a Probe that demonstrated 0.48nm repeatability (one sigma).nbsp; When scanned across the surface of the mirror a full topographical map of the surface ndash; and its surface errors ndash; can be produced.While the Phase I probe could only operate at rates of 10 measurements/second, we have developed optical power budget spreadsheets that model how 10,000 measurement can eventually be reached with currently available off-the-shelf components.nbsp; Furthermore, the Probe is generally not light-limited, and we believe that it can function with the weak back-scattered (non-specular) light from highly-polished highly-tilted surfaces, although this assertion will be tested in Phase II.Other work proposed in Phase II for the Nanometric Probe is directed at improving the current performance of the Probe to a level consistent with its full performance expectations.nbsp; In particular, the Probersquo;s light throughput and align-ability will be improved substantially.nbsp; With light throughput improvement we also expect to see a corresponding improvement in the Probersquo;s signal-to-noise ratio, which we are hopeful will reduce the Probersquo;s measurement uncertainty five-fold to less than 100 picometers (one sigma).Also, other factors limiting the measurement rate of the Probe, such as the capture rate of the spectrometer and the processing speed of the digital hardware, will be upgraded so that a rate of 1000 measurements/second can be achieved by the end of Phase II.nbsp; Finally, infrastructure will be procured and installed so that the Probersquo;s displacement measurements can be calibrated, and the Probersquo;s performance over its full operational envelope can be characterized.