Abstract: A hydrogen sensor, useful for trace hydrogen gas detection. The sensor involves providing a gas sample, generating modulated optical excitation sources, bringing the optical excitation source to the side of a metalized thin pyroelectric film, and detecting via a lock-in amplifier circuit the coherent differential signal resulting from thermoreflectance and thermoabsorptance changes in the film when exposed to hydrogen gas.

Abstract: A hydrogen sensor, useful for trace hydrogen gas detection. The sensor involves providing a gas sample, generating modulated optical excitation sources, bringing the optical excitation source to the side of a metalized thin pyroelectric film, and detecting via a lock-in amplifier circuit the coherent differential signal resulting from thermoreflectance and thermoabsorptance changes in the film when exposed to hydrogen gas.

Abstract: There is provided a metrologic methodology and instrument, useful for a high-spatial-resolution dynamic diagnostic metrology and instrument, which can provide simultaneous measurements of laser-induced frequency-domain infrared photothermal radiometry (FD-PTR) and alternating-current (ac) modulated luminescence (FD-LM) signals from defects and caries in teeth intraorally. The combination of the luminescence and radiometric frequency scan techniques for inspection of defects and caries in teeth involves irradiating the tooth with a modulated (direct-current (dc) to 100 kHz) excitation source (laser) emitting in the near-ultraviolet, visible, or near-infrared spectral range, generating blackbody Planck-radiation (infrared radiometry) and ac luminescence, and comparing the obtained (amplitude and phase) luminescence and radiometric signals to those obtained from a well characterized sample (reference) to provide the clinician with numerical information on the status of a tooth.

Abstract: There is provided a metrologic methodology, useful for in-situ, non-destructive monitoring, comprising a combination of novel signal generation and analysis techniques, computational techniques, and laser infrared radiometric instrumental configurations for measuring thermal and electronic properties of industrial semiconductor wafers and non-electronic materials. This methodology includes: the combination of the frequency sweep (Chirp) and conventional frequency scan techniques for rapid measurement of electronic and thermal transport properties of semiconductor and engineering materials/devices. The common-mode rejection demodulation (bi-modal pulse) method for detection of very weak inhomogeneities in materials, based on generating a real time periodic waveform consisting of two incident square-wave pulses.