Optoelectronic chromatic dispersion (OED) is a significant source of effective chromatic dispersion in photodiodes. We present an experimental and theoretical study of OED in PN-type Si photodiodes and photovoltaic cells and report on a very large effective chromatic dispersion in these devices. As measured with the modulation phase-shift technique at a frequency of 4 kHz for these slow devices, the OED spectral sensitivity for a commercial Si photodiode is approx.
View Article and Find Full Text PDFIt is known that PN-type photodiodes possess high optoelectronic chromatic dispersion (OED). Here we present a theoretical and experimental study of OED in PIN-type photodiodes. Applying the modulation phase-shift technique, a Ge PIN photodiode exhibits ∼0.
View Article and Find Full Text PDFWe demonstrate diagnosis of several machine-condition failures using wide-frequency-band interrogation of fiber Bragg grating (FBG) sensors. In collaboration with Israel's national water company Mekorot Ltd., a scaled-down version of a semi-submerged pumping system was constructed.
View Article and Find Full Text PDFOptoelectronic chromatic dispersion (OED) of a PN-type germanium photodiode is used for spectral sensing of ethanol concentration in water. A concentration sensitivity of 70 ppm is achieved. Spectral sensors based on OED in PN-type photodiodes can serve as low-cost on-chip devices for optical spectroscopy.
View Article and Find Full Text PDFThe spectral sensitivity of photodiode-based optoelectronic chromatic dispersion is enhanced by phase-shift amplification using RF interferometry. With phase-shift amplification of =4⋅10, a peak phase-shift sensitivity of Δθ = 27 deg/pm is achieved, corresponding to a spectral resolution of Δλ = 1 fm. This all-electronic solid-state technology can serve as an on-chip inexpensive technique for femtometer-resolved wavelength monitoring.
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