In this paper, a micro-opto-mechanical polymeric cantilever based Fabry Perot Interferometer(CFPI) is reported as an optical fiber sensor. To be able to fabricate the sensor, a mold for the polymeric cantilever was fabricated using poly methyl methacrylate (PMMA) and with which a polydimethylsiloxane (PDMS) cantilever was constructed. After releasing the cantilever from the mold, cantilever and SMF were integrated together. As a result, a cavity was formed between SMF cleaved end and cantilever surface. When vibration is applied, the distance between the cantilever free end and cleaved end SMF changes, consequently the optical patch length of the sensor structure altered dynamically. Here, the effect of different frequencies and their amplitudes on the sensor spectrum is studied by using FFT and STFT analysis method.
In this paper, we investigate the effect of acetone gas concentration on the transmission spectrum of a micro polymeric tapered optical fiber sensor. To study the effect of acetone concentration, the swelling effect of polydimethylsiloxane (PDMS) is studied. Presented sensor demonstrates acetone concentration sensitivity of ~4.1×10-4 nm/ppm in the range of 0 and 17600 ppm. Considering our interrogation unit resolution, minimum detectable concentration around ~4.8 ppm can be achieved.
Measurement of small force in biological applications could be helpful especially in the field of diagnostic and
prognostic procedure. For this purpose, a Hybrid Fabry Perot fiber optic Micro Cavity is proposed based on Micro Silica
Sphere Cavity integrated on the capillary tube, and is bound to the single mode fiber with PDMS layer. Since PDMS acts
as an elastic material, under small loads the cavity length was affected. To study this mechanical behavior, the sensor
structure was simulated with Finite element method. The force measurement was studied experimentally with analyzing
wavelength shifts of sensor. Consequently, the force sensitivity was equal to -3pm/mN. The force resolution of our
sensor was equal to 340 μN in the range of 0 to 950 mN.
In this article, an Adiabatic Tapered Optical Fiber -- Fabry Perot (ATOF-FP) Sensor is introduced as a simple refractive index sensor. This FP Cavity relies upon reflection from two cleave ends of ATOF sensor’s arms. Its spectrum was investigated with Distributed Feedback (DFB) tunable laser and photo detector. With analyzing the change in Optical Transmission Power (OTP) versus refractive index changes, the sensitivity of ATOF was -66.21 dB/RIU. In addition, the visibility of FP was studied. Its RI sensitivity was -0.975 1/RIU. The sensor resolution was 2.3 × 10-5 RIU with consideration of minimum detectable signal of acquisition system.
In this article, a novel Micro Silica Sphere Cavity Hybrid Fabry Perot optical fiber sensor is reported where refractive index (RI) and temperature can be simultaneously measured. The sensor is based on Micro Silica Sphere that was fabricated using a capillary tube. The micro silica sphere and optical fiber form a Hybrid Fabry Perot cavity. The temperature cross sensitivity of this sensor is small enough to be used for accurate RI measurement. The temperature sensitivity and RI sensitivity are -0.0028 dBm/ºC, -0.0044 dBm/ºC , -24.09 dBm/RIU and -20.6 dBm/RIU respectively, using two selected resonances.