We demonstrate spatially resolved sensing by a novel approach that combines an infrared camera and a simplified dual-comb illumination arrangement. Specifically, our scheme employs a continuous-wave laser and only one electro-optic modulator to simultaneously create a pair of mutually coherent optical frequency combs, each one with a slightly different line spacing. The system operates by measuring this dual-comb spectrum from a sequence of acquired images, in order to recover the spectral response of every spatial point of a sample.
View Article and Find Full Text PDFFlap procedures are complex surgical tools widely used in reconstructive surgery. Flap ischemia is one of the most dangerous complications, both during the surgical procedure and during the patient's recovery, which can quickly lead to tissue necrosis (flap loss) with serious medical and psychological consequences. Today, bedside clinical assessment remains the gold standard for flap monitoring, but timely detection of flap ischemia is a difficult and challenging task, so auxiliary techniques are needed to support flap monitoring.
View Article and Find Full Text PDFA sensitive optical microphone for photoacoustic spectroscopy based on the common path topology of a fibre laser Doppler vibrometer (FLDV) using phase-generated carrier demodulation and a slim diaphragm as an acoustic wave transducer was demonstrated. A resonant gas cell was adapted to enhance gas-detection performance and simultaneously provide efficient cancellation of the window background acoustic signal. Ammonia (NH) was selected as the target gas.
View Article and Find Full Text PDFA novel method is proposed for improving the performance of traditional laser heterodyne radiometry. The technique, which is based on the use of a wavelength modulated local oscillator laser, provides baseline-free spectra, lower limits of detection, and better precision and consistency than the conventional approach. This tool could, therefore, boost the accuracy of current terrestrial and planetary atmospheric studies.
View Article and Find Full Text PDFThe pathological skin phenotype caused by hyperglycemia is an important indicator for the progress of diabetes mellitus. An early detection of diabetes assures an early intervention to regulate the carbohydrate metabolism. In this publication a non-invasive detection principle based on the measurement of complex scattering parameters in the millimeter-wave frequency range is presented.
View Article and Find Full Text PDFChronic or sustained hyperglycemia associated to diabetes mellitus leads to many medical complications, thus, it is necessary to track the evolution of patients for providing the adequate management of the disease that is required for the restoration of the carbohydrate metabolism to a normal state. In this paper, a novel monitoring approach based on mm-wave spectroscopy is comprehensively described and experimentally validated using living animal models as target. The measurement method has proved the possibility of non-invasive, in-vivo, detection of hyperglycemia-associated conditions in different mouse models, making possible to clearly differentiate between several hyperglycemic states.
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