Speaker
Description
Detection of single photon or small number of photons is a key technology to bring about a breakthrough to optical probes for delicate biological samples, in the bio-research and the bio-industry alike. Optical transition edge sensor (optical TES) is one of the most promising single photon detectors for such applications, with its array of features including; broadband sensitivity which ranges from visible to infrared, energy resolution, virtually zero dark count, high temporal resolution and potential extremely high detection efficiency. Here we developed a single-photon spectral imaging system, where fibre-coupled optical TES constitutes a confocal fluorescent microscope. Owing to the high quantum efficiency and virtually zero dark count of the optical TES, our imaging setup allowed using extremely faint focused laser beam to excite a fluorescent specimen, emission from which are led to the TES through an optical fibre. The energy resolution of TES allowed us to reconstruct a spectral microscopy image of the specimen without any dispersion elements (e.g. diffraction gratings). The figure shows a spectral image of a fluorescent-dye labelled mammalian cell specimen, taken with 488 nm excitation wavelength (Output under the object ~ 120 nW). The optical TES enabled to reconstruct the clear spectral image with extremely small photon count (photon count for each pixel in the figure is merely <100). These results demonstrate that the optical TES based micro spectral imaging system is capable of high-sensitivity photon spectral imaging at an extremely photon-starved regions. Taken together, our results present a blue print for a virtually non-invasive “probe without trace” optical cell analysis method, that is particularly ideal for highly demanding application such as quality control for cells used in regenerative medicines.
Student (Ph.D., M.Sc. or B.Sc.) | N |
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Less than 5 years of experience since completion of Ph.D | N |