A stepped Mach-Zehnder interferometric humidity sensor based on lateral offset fusion splicing

Fiber-Optic Chemical Sensors and Biosensors (2015–2019)

“…151 When operated at 1558 nm, the sensitivity is highest (0.14 dB/% RH), and the sensor has a response time of 1 s. Without the gelatin coating, a similar Mach−Zehnder interferometer based RH sensor only has a sensitivity of −0.0487 dB/% RH. 152 A mesoporous composite film made from poly(allylamine hydrochloride) (PAH) and silica nanoparticles was deposited on an optical fiber and formed a FOCS for humidity. 153 The sensing film behaved like a Fabry−Perot cavity, the absorption of water changed the optical thickness and resulted in changes in reflection.…”

“…A single-mode-side polished multimode/single-mode fiber structure was coated with gelatin and used as a FOCS for RH . When operated at 1558 nm, the sensitivity is highest (0.14 dB/% RH), and the sensor has a response time of 1 s. Without the gelatin coating, a similar Mach–Zehnder interferometer based RH sensor only has a sensitivity of −0.0487 dB/% RH . A mesoporous composite film made from poly­(allylamine hydrochloride) (PAH) and silica nanoparticles was deposited on an optical fiber and formed a FOCS for humidity .…”

Comparative spectral tuning and fluctuation analysis of an all-fiber Mach–Zehnder interferometer and micro Mach–Zehnder interferometer

“…The spectral response of MMZI with variable fringe widths shows higher sensitivity than that of the wavelength spectrum with uniform free spectral range (FSR) [11]. With regard to the tapered fiber, recently, diverse designs of inline MZI have been reported [12] with a wide variety of applications, which include the gain equalization of amplified spontaneous emission (ASE) response of an erbium-doped fiber amplifier (EDFA) [13], multi-wavelength laser [14][15][16][17][18][19][20], all-optical switching [21], wearable respiration monitoring [22], detection of ammonia [23], detection of uric acid [24], hydrogen sulfide gas [25], sensing of refractive index , curvature [52][53][54][55][56][57][58][59], temperature [60][61][62][63][64][65][66][67], strain [68][69][70][71], humidity [72][73][74][75], pressure [76,77], magnetic field [78][79][80], DC…”