A high performance Doppler interferometer for advanced optical storage systems

The design thinking implementation, and testing results of a newly developed Doppler interferometer is described. The three built-in measuring modes including (1) single-beam mode for measuring absolute vibration. (2) dual-beam for measuring differential vibration, and (3) distance measuring, are all presented. To facilitate the application of this interferometer for advanced optical storage applications, a circular polarization interferometer configuration was adopted to arrive at a compact size and to enable the adoption of a built-in microscopic imaging system that can be used both as an alignment aid and as a sample imaging system. The configuration of the inherent dynamic system analysis capabilities that can be used to investigate the Bode plot of optical storage systems is also examined in detail. The nanometer resolution and megahertz bandwidth capabilities of this interferometer were verified in various advanced optical storage systems related experiments.