Intensity-modulated optical fiber sensors based on chirped-fiber Bragg gratings

Abstract

Intensity-modulated fiber Bragg grating (FBG) sensors, compared with normal wavelength-encoding FBG sensors, can reduce the cost of sensor system significantly by using cost-efficient optical power detection devices, instead of expensive wavelength measurement instruments. Chirped-FBG (CFBG) based intensity-modulated sensors show potential applications in various sensing areas due to their many advantages, including inherent independence of temperature, high measurement speed, and low cost, in addition to the merits of all fiber-optic sensors. This paper theoretically studies the sensing principle of CFBG-based intensity-modulated sensors and briefly reviews their recent progress in measurement of displacement, acceleration, and tilt angle.

Design in line LMA-10 Photonic Crystal Fiber MZI for Detection and investigation of Beta Thalassemia

“…Intensity modulation was used in early optical sensor development due to its low cost, simplicity, and reliability (13,14) . This intensity modulated signal comes from Fiber Bragg grating as a sensing head that may be used as optical band pass or notch filters (15,17) .The traditional tests of beta thalassemia trait is by hemoglobinopathy analysis and complete genotype which identified the beta thalassemia trait .Beta thalassemia trait also is an important manner for decreasing the expression of HbA2 with level as low as 3.6% on high performance liquid chromatography (HPLC).This type of anemia needs regular blood transfusions and special medical care through their life.…”

All-fiber acceleration sensor with temperature self-compensation

“…For instance, the fiber Bragg gratings were attached on the surface of the beam to detect the vibration because the vibration of the beam induces the strain change of the grating [1][2][3], and the typical temperature sensitivity is ~4~10pm/℃. And the standard deviation of temperature is ~4pm after the special multi-core fiber is used [4].…”