Time-domain optical sensing

Abstract

was recorded over 180" using a hemicylindrical screen of photosensitive paper (Kodak Panalure) with the capillary at the centre. (i) and (ii) in Fig. 3 show the response of a water-filled, uncoated capillary under TE and TM illumination, adjusted to strike a broad range of angles and to highhght the region of the capillary response corresponding to reflections from the internal surface

Hybrid Dispersion Laser Scanner

“…First, the broadband spectrum of an optical pulse is mapped into a temporal waveform by temporal dispersion. This step is known as wavelength-to-time mapping222324 or dispersive Fourier transformation2526272829 and is performed using large group-velocity dispersion (GVD) in dispersive fibers or chirped fiber Bragg gratings. Second, the temporal waveform is converted by spatial dispersion into a 1D rainbow pulse in space.…”

“…For this purpose, we perform dispersive Fourier transformation in the 800 nm spectral band for the first time. Previously, dispersive Fourier transformation has been restricted to the fiber-optic communication band centered at ∼1550 nm due to the commercial unavailability of dispersive fibers with high dispersion-to-loss ratio outside the ∼1550 nm band22232425272829. On the contrary, shorter wavelengths are desirable since the spectral resolution limited by diffractive elements (or equivalently the HDLS's number of resolvable points) improves with shorter wavelengths (See Methods).…”

Correction: Corrigendum: Parametric spectro-temporal analyzer (PASTA) for real-time optical spectrum observation

“…The authors neglected to cite some of the previous studies related to Fourier Transformation in the Introduction section of this Article1234. These additional references are listed below as references 1,2,3,4, and should appear in the text as below.…”

“…These additional references are listed below as references 1,2,3,4, and should appear in the text as below.…”

“…After wavelength-to-time mapping, the spectrum can be captured by a single-pixel detector and a real-time oscilloscope. Its first demonstration in applying DFT spectroscopy3 was not as practical until the introduction of optical amplification as in ADFT4.”…”