Ultrafast and scan-less three-dimensional imaging using all-optical information conversion with chirped optical frequency comb

Fully scan-less three-dimensional imaging method was developed by use of an optical frequency comb. Interferometric measurement between chirped pulse train realized ultrafast information conversion between space, time, and color. Three-dimensional shape information of an object is thus obtained by two-dimensional spectral interference fringe image in a single pulse. With precisely controlled optical frequency combs, precise phase control of optical waves in a pulse train is utilized for all-optical Hilbert tansform to extract amplitude and phase of the obtained interference fringe image, thus two-dimensional spectroscopy is realized. With a monochromatic camera, three-dimensional image is obtained without any scanning. The developed method was applied to shape measurements of various targets with micrometer to nanometer resolution. Since pulse-to-pulse interferometer is utilized, a large object can be measured without losing high accuracy. Scan-less method can be applied to capturing moving target and ultrafast phenomena.