Applied Sciences · 2019 · 61 citations · 31 references
Thz PhotonicsTerahertz TechnologyTerahertz Time-domain SystemEngineeringOptical CharacterizationTerahertz PhotonicsOptical PropertiesInstrumentationOptical SpectroscopyOptical SamplingPhotonicsElectrical EngineeringTerahertz SpectroscopyPhysicsTerahertz ScienceEcops SetupOptical SensorsTerahertz DevicesFastest Thickness MeasurementNatural SciencesSpectroscopyApplied PhysicsTerahertz TechniqueFastest Thickness MeasurementsElectronically Controlled OpticalTerahertz Applications
We apply a fast terahertz time-domain spectroscopy (TDS) system based on electronically controlled optical sampling (ECOPS) to contact-free thickness gauging. Our setup achieves a measurement speed of 1600 terahertz pulse traces per second, which—to our knowledge—represents the fastest thickness measurement performed with any terahertz system to-date. Using a silicon wafer as a test sample, we compare data of the ECOPS experiment to results obtained with a conventional terahertz TDS system and a mechanical micrometer gauge. We show that all systems provide consistent results within the measurement accuracy. Moreover, we perform thickness measurements of a rapidly moving sample and characterize the ECOPS setup with respect to time-domain dynamic range, signal-to-noise ratio, and spectral properties.
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The HITRAN2016 molecular spectroscopic database
Iouli E. Gordon, Laurence S. Rothman, C. Hill et al. · Journal of Quantitative Spectroscopy and Radiative Transfer · 2017 · 7.9K citations · Full text