High-speed optical imaging is an essential tool for studying fast dynamics in plasma physics, microfluidics, phononics, and photochemistry. Unfortunately, conventional cameras based on CCD and CMOS image sensors are not fast enough to capture such events with high sensitivity. This is due to the fundamental trade-off between sensitivity and speed – at high frame rate, fewer photons are detected during each frame. In this talk, I introduce unconventional approaches to high-speed optical imaging that overcome the trade-off in the traditional image sensors and offer a record high frame rate and shutter speed without sacrificing sensitivity. I also present a new class of biomedical applications enabled by the technology such as high-throughput screening for cancer detection and drug discovery.

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The interaction of light with metal nanostructures gives rise to the collective oscillation of electrons, which can be engineered to resonate at different wavelengths by tuning the size and geometry of the structures. This phenomenon can be used to create high-resolution color prints. While the resolution of inkbased color printers is limited to ~1,000 dots-per-inch (dpi) due to the intermixing and the size of the ink drops, nanostructured metal can achieve prints at ~100,000 dpi1. At this resolution, different color pixels with dimensions of ~ 250 nm can be juxtaposed without registration errors, and color prints can be achieved at the optical diffraction limit.

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We used a spatial light modulator to project optical micropatterns with an intensity gradient on lung cancer cell A549. We observed that the amounts of reactive oxygen species (ROS) in cells were in proportion to the optical intensity, and the optical intensity gradients could drive directional cell migration.

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Human blood coagulation is investigated by instant and temporal THz spectra measurement of 56 ex-vivo human blood samples either with or without adding anticoagulant. Our result indicates a high sensitivity of THz wave to the first-stage platelet aggregation and amplification process, but not the later stage blood clotting process.

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