Abstract: Described are various technologies pertaining to identifying a dominant frequency in an acquired signal, such as a frequency corresponding to a human heartbeat in an acquired video signal. In connection with identifying the dominant frequency, a sub-signal of the acquired signal is extracted from the acquired signal, where the sub-signal includes Nsamples number of samples (frames). A looped signal is generated by looping the sub-signal. Nsamples is incremented, and the process is repeated until Nsamples is equivalent to a predefined threshold; accordingly, numerous looped signals are formed. The dominant frequency is identified based upon the looped signal and presented with the corresponding uncertainty based on harmonic analysis.

Abstract: A hyperspectral stimulated emission depletion (“STED”) microscope system for high-resolution imaging of samples labeled with multiple fluorophores (e.g., two to ten fluorophores). The hyperspectral STED microscope includes a light source, optical systems configured for generating an excitation light beam and a depletion light beam, optical systems configured for focusing the excitation and depletion light beams on a sample, and systems for collecting and processing data generated by interaction of the excitation and depletion light beams with the sample. Hyperspectral STED data may be analyzed using multivariate curve resolution analysis techniques to deconvolute emission from the multiple fluorophores. The hyperspectral STED microscope described herein can be used for multi-color, subdiffraction imaging of samples (e.g., materials and biological materials) and for analyzing a tissue by Förster Resonance Energy Transfer (“FRET”).