K. Hiramatsu 교수

Effects of reactor pressure on the epitaxial lateral overgrowth (ELO) via low pressure MOVPE have been studied in relation to the growth temperature. For the ELO GaN on SiO2 stripes along the 〈11-00〉 direction of the underlying GaN, by decreasing reactor pressures from 500 to 40 Torr or by increasing growth temperatures from 950 to 1050 °C, the (0001) surfaces become broad and the side walls are varied from inclined {112-2} surfaces to vertical {112-0} surfaces. For stripes along the 〈112-0〉 dir

Flow cytometry is an indispensable tool in biology for counting and analyzing single cells in large heterogeneous populations. However, it predominantly relies on fluorescent labeling to differentiate cells and, hence, comes with several fundamental drawbacks. Here, we present a high-throughput Raman flow cytometer on a microfluidic chip that chemically probes single live cells in a label-free manner. It is based on a rapid-scan Fourier-transform coherent anti-Stokes Raman scattering spectromete

We report the first observation of Raman optical activity (ROA) by coherent anti-Stokes Raman scattering. Thanks to the more freedom of polarization configurations in coherent anti-Stokes Raman scattering than in spontaneous Raman spectroscopy, the contrast ratio of the chiral signal to the achiral background has been improved markedly. For (-)-β-pinene, it is 2 orders of magnitude better than that in the reported spontaneous ROA measurement. This is also the first measurement of ROA signal usin

We report the development of broadband and sensitive time-resolved circular dichroism (TRCD) spectroscopy by exploiting optical heterodyne detection. Using this method, transient CD signals of submillidegree level can be detected over the spectral range of 415-730 nm. We also demonstrate that the broadband measurement with the aid of singular value decomposition enables the discrimination of genuine TRCD signals from artificial optical-anisotropy, such as linear birefringence and linear dichrois

Dual-comb coherent Raman spectroscopy is a powerful tool for rapidly probing vibrational signatures of molecules in the fingerprint region. However, >99% of its incident laser energy is unused and wasted since the duty cycle of its spectral acquisition is only less than 1% due to the mismatch between the interval of the laser pulses (>1 ns) and the coherence lifetime of molecular vibrations (∼3 ps). Here we demonstrate ∼100% duty-cycle dual-comb coherent Raman spectroscopy with a “quasi”-dual-co

Abstract Cell sorting is the workhorse of biological research and medicine. Cell sorters are commonly used to sort heterogeneous cell populations based on their intrinsic features. Raman‐activated cell sorting (RACS) has recently received considerable interest by virtue of its ability to discriminate cells by their intracellular chemical content, in a label‐free manner. However, the broad deployment of RACS beyond lab‐based demonstrations is hindered by a fundamental trade‐off between throughput

Abstract We demonstrate broadband Fourier‐transform coherent anti‐Stokes Raman scattering (FT‐CARS) spectral microscopy with a pixel dwell time of 42 μs, which is ~50 times shorter than the shortest‐to‐date pixel dwell time for CARS spectral microscopy. Our broadband FT‐CARS spectral microscope is composed of an FT‐CARS spectrometer, a rapid galvanometric scanner, and a high‐speed image acquisition circuit, enabling a frame rate of 2.4 fps with a pixel resolution of 100 × 100 pixels, a bandwidth