Spectral sensor of the ethanol concentration in water based on photodiode optoelectronic chromatic dispersion

Abstract

Optoelectronic 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.

Optoelectronic oscillator controlled by photodiode-based optoelectronic chromatic dispersion and FBG integration

“…By integrating a Ge PN photodiode with an FBG interrogation system, a wavelength-shift resolution 𝑜𝑓 𝛥𝜆𝑟𝑒𝑠 = 1.25 𝑝𝑚/√𝐻𝑧 was achieved. Furthermore, the OED sensitivity of the photodetector was enhanced by RF interferometry-based phase-shift amplification of 𝐺 = 4𝑥10 4 , resulting in femtometer-resolution wavelength monitoring [3]. OED was also utilized for high sensitivity spectral sensing of ethanol in water [4].…”