Arbitrary two-dimensional spectrally encoded pattern generation—a new strategy for high-speed patterned illumination imaging

Abstract

Patterned illumination is now a proven technique in optical metrology and imaging, and is widely employed in both industrial and biological applications. However, existing techniques are unable to meet the pressing need for higher imaging rates. To address this challenge, we propose and demonstrate two-dimensional (2D) mechanical-scan-free arbitrary patterned illumination by 2D spectral encoding. The illumination pattern is flexibly generated at high speed by spectral shaping together with wavelength-to-2D space mapping. Performance optimization of this new patterned illumination scheme (e.g., pattern distortion and resolution) is generally an ill-defined problem involving multiple interrelated parameters. We demonstrate proof-of-principle experiments based on a multiobjective optimization routine using a genetic algorithm to validate our optimization model as well as to show the feasibility of patterned illumination by use of spectral interferometry. Adopting the wisdom of high-speed arbitrary waveform generation routinely practiced in telecommunications as well as ultrafast wavelength-sweep mechanisms, the proposed method could have an impact on advanced imaging modalities, particularly when speed is of a critical concern.