Humidity sensor based on photonic crystal fibre interferometer

Humidity sensor based on a single-mode hetero-core fiber structure

“…Compared with electronic RH sensors, optical fiber based RH sensors offer numerous advantages, such as immunity to electromagnetic interference, small size, low weight, and remote monitoring. A wide range of RH sensing techniques based on optical fibers has been reported previously, including long period gratings (LPG) [1][2][3], fiber Bragg gratings [4,5], side polished fibers [6], plastic optical fibers [7], surface plasmon resonance [8,9], photonic crystal fiber interferometer [10], and tapered optical fibers [11,12]. Recently Akita proposed to use a heterocore optical fiber as a humidity sensor, which is based on a multimode-singlemode-multimode fiber structure with the benefits of simplicity and low cost [13].…”

Photonic crystal fiber interferometer for dew detection

“…0733-8724/$26.00 © 2011 IEEE where, C and are the so-called Magnus parameters for the temperature range to 60 C. Photonic crystal fiber interferometers have attained great importance in recent times due to the simple fabrication process involved and excellent sensing performance [14]- [22]. In a PCFI the excitation and recombination of modes can be carried out by the hole collapsed region of the PCF [14], [18].…”

“…A regular interference pattern in the reflection spectrum of the PCFI suggests that only two modes are interfering in the device. In our reported work [22] on a PCFI using LMA 10 fiber, based on the fact that higher order modes can exist in the core of a PCF with a short length [23], [24], we considered the interfering modes in the PCF to be two core modes. However in a later experiment, which involved varying the refractive index surrounding the cladding of a PCFI, we have observed good ambient refractive index sensitivity for a PCFI fabricated using the same LMA 10 fiber.…”

“…We have recently reported the relative humidity response of a PCFI [22]. An increase in humidity causes the shift of the interference pattern of a PCFI toward longer wavelengths and the value of this interference peak shift is exponential with respect to relative humidity.…”

Variable Waist-Diameter Mach–Zehnder Tapered-Fiber Interferometer as Humidity and Temperature Sensor

“…Consequently, it affects the transmission and reflection of the guided light that interacts with the surrounding medium. Optical fiber humidity sensors are currently a topic of major research interest [5][6][7][8][9] that mostly utilize the interaction of the evanescent field of the tapered fiber with the surrounding. An optical humidity sensor based on reversible absorption of water from the surrounding medium of tapered fiber in vicinity of spongy thin film interferometer has been reported by Muto et.…”