A micro structure folded cladding porous shaped with circular air hole photonic crystal fiber (FP-PCF) is proposed and numerically investigated in a broader wavelength range from 1.4 µm to 1.64 µm (E+S+C+L+U) for chemical sensing purposes. Employing finite element method (FEM) with anisotropic perfectly matched layer (PML) various properties of the proposed FP-PCF are numerically inquired. Filling the hole of core with aqueous analyte ethanol (n = 1.354) and tuning different geometric parameters of the fiber, the sensitivity order of 64.19% and the confinement loss of 2.07 × 10- 5 dB/m are attained at 1.48 µm wavelength in S band. The investigated numerical simulation result strongly focuses on sensing purposes; because this fiber attained higher sensitivity with lower confinement loss over the operating wavelength. Measuring time of sensitivity, simultaneously confinement loss also inquired. It reflects that confinement loss is highly dependable on PML depth but not for sensitivity. Beside above properties numerical aperture (NA), nonlinearity, and effective area are also computed. This FP-PCF also performed as sensor for other alcohol series (methanol, propanol, butanol, pentanol). Optimized FP-PCF shows higher sensitivity and low confinement loss carrying high impact in the area of chemical as well as gas sensing purposes. Surely it is clear that install such type of sensor will flourish technology massively.

https://cyberleninka.org/article/n/1462119.pdf

Folded cladding porous shaped photonic crystal fiber with high sensitivity in optical sensing applications: Design and analysis

In this paper, a slotted core photonic crystal fiber (PCF) has been designed. A rigorous numerical investigation has been done over the wider range of the wavelength from 1.30 µm to 2.0 µm near inferred region (IR). By employing full vectorial finite element method (FV-FEM) having completely circular anisotropic perfectly matched layer (C-PML) different optical parameter such as nonlinearity, confinement loss, sensitivity, beat length, V-parameter and splice loss of the modeled PCF have been uncovered. The investigated upshot testifies that the birefringence gained at the order of 10−2. Nevertheless, the proposed fiber experienced with the lower order (1.26 × 10−5 dB/m) of confinement loss with a higher order of nonlinearity 54.33 W−1 km−1 at simultaneously at the operating optical wavelength λ = 1.33 µm. Moreover, the impacts of the geometric parameters have been turned on birefringence, nonlinearity and confinement losses which are also analyzed in detail. The proposed PCF model with investigated results provides stronger evidence that, the structure will play a substantial role in the area of optical waveguides as well as optical devices or instrumentations.

Design and analysis of slotted core photonic crystal fiber for gas sensing application

A compact polarization beam splitter based on a gold-filled photonic crystal fiber with a square lattice is proposed. The full vector finite element method is used to design and characterize the proposed ultra-compact and ultra-broadband polarization splitter. The plasmonic plays an important role in order to achieve an ultra-short length of 56.33 µm with a high extinction ratio of 132.92 dB at the wavelength of 1.55 µm. It can ensure an ultra-broad bandwidth of 530 nm, from 1225 to 1755 nm, covering all the communication bands with an extinction ratio better than 20 dB. The proposed polarization splitter may be a promising candidate in communication due to its ultra-short length and ultra-broad bandwidth.

Ultra-short polarization splitter based on a plasmonic dual-core photonic crystal fiber with an ultra-broad bandwidth

The thermal phase noise in giant interferometric fiber optic gyroscopes (fiber length L > 10 km) and its impact on the detection sensitivity are theoretically derived and experimentally verified. It is confirmed that thermal phase noise cannot be overlooked for the giant IFOGs. Utilizing high order eigen frequency modulation can effectively suppress the walk-off component of thermal phase noise, but the residual part contributes to high-frequency range thus limits the detection bandwidth of giant IFOGs. The self-noise is experimentally demonstrated as 3.5 nrad/s/Hz at low frequencies and 5.2 nrad/s/Hz at 100 Hz in the IFOG with a 30-km single mode fiber coil. Discussions about the fiber characteristics on thermal phase noise are presented, which paves the way to the design of giant IFOGs.

Thermal phase noise in giant interferometric fiber optic gyroscopes.

Highly birefringent photonic crystal fiber with hybrid cladding

Novel pentagonal photonic crystal fiber with high birefringence, large flattened negative dispersion, and high nonlinearity is proposed. The dispersion and birefringence properties of this structure are simulated and analyzed numerically based on the full vector finite element method (FEM). Numerical results indicate that the fiber obtains a large average dispersion of -611.9  ps/nm/km over 1,460-1,625 nm and -474  ps/nm/km over 1425-1675 nm wavelength bands for two kinds of optimized designs, respectively. In addition, the proposed PCF shows a high birefringence of 1.67×10-2 and 1.75×10-2 at the operating wavelength of 1550 nm. Moreover, the influence of the possible variation in the parameters during the fabrication process on the dispersion and birefringence properties is studied. The proposed PCF would have important applications in polarization maintaining transmission systems, residual dispersion compensation, supercontinuum generation, and the design of widely tunable wavelength converters based on four-wave mixing.

Design of a pentagonal photonic crystal fiber with high birefringence and large flattened negative dispersion

Thermal effects of fiber sensing coils in different winding pattern considering both thermal gradient and thermal stress

Design of short polarization splitter based on dual-core photonic crystal fiber with ultra-high extinction ratio

The invention discloses an optical fiber gyroscope with an optical fiber ring adopting a double-ring design. The optical fiber gyroscope comprises a light source, a photoelectric detector, an optical fiber coupling device, a signal processor, an optical modulator and an interference part, wherein the interference part comprises two optical fiber rings and a heat insulation device; the heat insulation device comprises an inner cavity and an outer cavity; a hard insulating ring is mounted between the inner cavity and the outer cavity; a heat guide groove is mounted in the inner cavity; the two optical fiber rings are symmetrically mounted on the two sides of the heat guide groove; a small hole is formed in the heat guide groove; corresponding ends of the two optical fiber rings are spliced and a splicing point is located in the small hole of the heat guide groove; leading-out ends of the two optical fiber rings are led out from other small holes of the heat guide groove and penetrate through the inner cavity and the outer cavity respectively; the leading-out end of one optical fiber ring is connected with a first output end of the optical modulator and the leading-out end of the other optical fiber ring is connected with a second output end of the optical modulator; and the small holes on the heat guide groove are sealed, and the inner cavity and the outer cavity are sealed. The optical fiber gyroscope has the advantages of high temperature stability.

Optical fiber gyroscope with optical fiber ring adopting double-ring design

The invention aims at providing a method for testing the property of a high-accuracy fiber-optic gyro on the basis of the dynamic condition of an incremental method. The method comprises the following steps of calibrating the fiber-optic gyro under a static condition, and determining a scale factor, an installation error angle and a zero correction value; installing the fiber-optic gyro on a rotating table, rotating the fiber-optic gyro towards the sky so as to enable the Z shaft of the fiber-optic gyro to be perpendicular to a horizontal surface, recording the output angular speed Ne of the fiber-optic gyro within time t, and calculating the output average value of the fiber-optic gyro; controlling the rotation time T of the rotating table, recording N discrete gyro output values output from the Z shaft of the fiber-optic gyro under the condition of a sampling time interval dt, and recording the rotation angle of the rotating table within time T; determining the rotation angle of the fiber-optic gyro within the time T by adding the N fiber-optic gyro output values and subtracting angular speed caused by the autorotation of the earth within the time, and comparing the rotation angle of the fiber-optic gyro with the rotation angle of the rotating table. The method provided by the invention can effectively reflect the light error of the high-accuracy fiber-optic gyro under the dynamic condition.

Zhang Zhiyong

Papers

Design of a pentagonal photonic crystal fiber with high birefringence and large flattened negative dispersion

Thermal effects of fiber sensing coils in different winding pattern considering both thermal gradient and thermal stress

Design of short polarization splitter based on dual-core photonic crystal fiber with ultra-high extinction ratio

Optical fiber gyroscope with optical fiber ring adopting double-ring design

Method for testing property of high-accuracy fiber-optic gyro on basis of dynamic condition of incremental method