Cascade-Linked Multiple-Synthetic-Wavelength Digital Holography Using Optical Frequency Synthesizer

Abstract

We present multiple-synthetic-wavelength digital holography using an optical frequency synthesizer (OFS) phaselocked to an optical frequency comb. The cascaded links of multiple synthetic wavelengths and a single optical wavelength generated by an OFS enable 3D shape measurements with a wide axial dynamic range and high-axial resolution. We demonstrate the shape measurements of a 1-mm step surface with an axial precision of a few tens of nm by cascading five synthesized wavelengths and a single optical wavelength.