8 May 2014 Time-stretched spectrally encoded angular light scattering for high-throughput real-time diagnostics
Author Affiliations +
The angular light scattering profile of microscopic particles significantly depends on their morphological parameters, such as size and shape. This dependency is widely used in state-of-the-art flow cytometry methods for particle classification. We recently introduced the spectrally encoded angular light scattering (SEALS) method, with potential application in scanning flow cytometry (SFC). We show that a one-to-one wavelength-to-angle mapping enables the measurement of the angular dependence of scattered light from microscopic particles over a wide dynamic range. Improvement in dynamic range is obtained by equalizing the angular scattering dependence via spectral equalization. The resulting continuous angular spectrum is obtained without mechanical scanning, enabling single-shot measurement. Using this information, particle morphology can be determined with improved accuracy. We derive and experimentally verify an analytic wavelength-to-angle mapping model, facilitating rapid data processing. As a proof of concept, we demonstrate the method’s capability of distinguishing differently sized polystyrene beads. The combination of SEALS with time-stretch dispersive Fourier transform (TS-DFT) offers real-time and high-throughput (high frame rate) measurements and renders the method suitable for integration in standard flow cytometers: By transforming the spectrum into time and slowing the time scale, using group velocity dispersion (GVD), single-shot spectra can be obtained at high throughput, using a photodiode and a real-time digitizer. The amount of group velocity dispersion is chosen to time-stretch the optical pulses, that is, to slow them down, such that they do not overlap and may be digitized in real-time.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jost Adam, Jost Adam, Ata Mahjoubfar, Ata Mahjoubfar, Eric D. Diebold, Eric D. Diebold, Brandon W. Buckley, Brandon W. Buckley, Bahram Jalali, Bahram Jalali, "Time-stretched spectrally encoded angular light scattering for high-throughput real-time diagnostics", Proc. SPIE 9129, Biophotonics: Photonic Solutions for Better Health Care IV, 91291A (8 May 2014); doi: 10.1117/12.2052463; https://doi.org/10.1117/12.2052463

Back to Top