Fabry–Perot Interferometer-Based Absolute Pressure Sensor With Stainless Steel Diaphragm

A Dual-Cavity Fabry–Perot Interferometric Fiber-Optic Sensor for the Simultaneous Measurement of High-Temperature and High-Gas-Pressure

“…The most common type of such a sensor is a DFPI, which is a temperature-pressure composite sensor [9], [10]. Generally, there are two ways for EFPIs to measure pressure, including the diaphragm type [11], and diaphragm-free type [12]. A femtosecond laser was employed to ablate a film at the end of a fiber and form a pressure sensor with a measurement range of 0-0.7 MPa, and a cascaded IFPI achieved a large temperature measurement range of 20-700 • C [13].…”

“…A DFPI fiber sensor, which achieves a wide range of simultaneous temperature and pressure measurements with a measurement range of 0-10 MPa at 40-1100 • C, was demonstrated in a previous study [14]. In addition, in terms of the fabrication process, the previously reported DFPI hybrid structures, which use either chemical etching [15] or laser micromachining [11], require a complicated series of steps or expensive equipment.…”

Design and Implementation of a Novel Measuring Scheme for Fiber Interferometer Based Sensors

“…In the literature, the development of all-fiber interferometers with different configurations has yielded considerable results, such as fiber-optic Michelson interferometers (FMI) [1,2,3,4], fiber-optic Mach–Zehnder interferometers (FMZI) [5,6,7,8], fiber-optic Fabry–Perot interferometers (FFPI) [9,10,11,12,13,14,15,16,17], and fiber-optic Fizeau interferometers (FFI) [18,19]. Typical FI based sensing systems and application examples have been categorized into 13 types, according to the measured parameters, i.e., temperature [20,21], mechanical vibration [22,23], acoustic wave [22,24], ultrasound [25,26], voltage [27,28], magnetic field [29,30], pressure [20,31], strain [21,32], flow velocity [33,34], humidity [35,36], gas [37,38], liquid level [39,40], and the refractive index (RI) [41,42]. Li et al [20] proposed a cascaded-cavity FFPI to simultaneously sense air pressure and temperature.…”

“…A compact magnetic field sensor was designed based on a S-taper and an up-fusion-taper multimodal interference [30]. An absolute pressure sensor was designed based on an external FFPI enclosed in a vacuum cell [31]. Tang et al [32] designed a dual-tapered photonic crystal fiber (PCF) based FMZI for strain sensing.…”

“…In the above reviewed FI based sensing systems, the design of hardware systems and measuring mechanisms for achieving the desired sensing purposes can be summarized into three combinations: (1) the integration of broadband light source (BLS), optical spectral analyzer (OSA), circulators or power splitters and personal computer (PC) [20,21,30,31,33,35,36,37,40,41]; (2) the integration of an amplified spontaneous emission (ASE) or ASE with tunable optical filter (TOF), photodiode module (PM), data acquisition module (DAQM), circulators or optical couplers (OC) and PC [22,27,38]; (3) the integration of distributed feedback laser (DFBL) or DFBL with the erbium doped fiber amplifier (EDFA), PM or OSA, OC with wavelength-division multiplexer (WDM) module and PC with DAQM [24,25,26,28,29,32,34,39]. The common disadvantage of the existing systems and sensing methods mentioned above include high-cost, as well as being bulky and relatively slow in measuring speed if OSA is used.…”