A new single-polarization wavelength splitter based on the photonic crystal fiber (PCF) has been proposed. The full-vector finite-element method (FEM) is applied to analyze single-mode guiding properties. Splitting of two different wavelengths realized by adjusting structural parameters. semi-vector three-dimensional beam propagation employed confirm splitting characteristics PCF. Numerical simulations show that 1.3 μm and 1.55 are split for a length 10.7 mm with in each core. crosstalk...

A cost-efficient all fiber temperature sensor based on a Sagnac interferometer is proposed and experimentally demonstrated. The comprises section of thin core (TCF) in combination with Panda type polarization maintaining (PMF). key point that the TCF intentionally aligned to one two stress areas PMF order change mode transmission. Then prepared TCF-PMF structure built into loop. well-defined spectrum obtained fringe contrast reaches up 28 dB. dip wavelengths are employed demonstrate...

A novel photonic crystal fiber (PCF) with a single core, rather than two cores, for wavelength splitting application has been proposed through the full-vector finite-element method. The light located in 1.31- and 1.55- μm bands propagates orthogonal polarization states fiber. For propagation distance of 20 mm, 20-dB bandwidth same x- or y-polarized modes within could, respectively, reach 20.5 45.3 nm, which is much wider that two-core PCF.

Abstract A fiber optical curvature sensor comprising a concave‐heterotypic cascaded structure built into Sagnac loop is demonstrated experimentally. section of multimode sandwiched between the single mode and polarization maintaining in order to construct structure. The concave presented used effectively excite guided modes. spectra proposed bending will shift toward long wavelength with curvature. measured sensitivity 11.6 nm/m −1 has been achieved. characterizes cost‐efficient, simple...

Temperature and twist characteristics of cascaded long period fiber gratings (LPFGs) written in PANDA polarization-maintaining fibers have been experimentally investigated. The temperature sensitivity the proposed structure reaches 102.6 pm °C−1. amplitude peak decreases as is rotated clockwise, whereas it increases counterclockwise. resonance wavelength responds linearly to ratio with a 0.072 nm (rad m−1)−1 for range ±21 rad m−1. could be employed sensing applications.

A novel, cost-efficient all-fiber temperature sensor is proposed and demonstrated experimentally. The consists of single-mode-multimode-polarization-maintaining-multimode-single-mode fiber structure reeled into a circle based on Sagnac loop. Its characteristic investigated sensitivity reaches up to 1.476 nm/°C for the radius 7 cm. Experimental results show that has significant influence theoretical analysis expressed.

A temperature- and strain-insensitive torsion sensor is proposed demonstrated by utilising a phase-shifted ultra-long-period grating. Experimental results demonstrate that the separation of phase shift resonant peaks changes with twist rate, but remains invariant temperature or strain changes. In addition, it was found influence twisting to fibre grating non-uniform along axis.

A new type broadband single-polarization single-mode photonic crystal fiber based on index-matching coupling is proposed by using the full vector finite-element method. Polarization-dependent loss of larger than 24.08 dB/m within a wavelength range from 1.25 to 1.65 , and operation bandwidth reaches 400 nm.

We experimentally demonstrated a simple and effective method to write long period fiber gratings (LPFGs) with low grating birefringence using high frequency CO2 laser pulses. Such LPFGs were fabricated by introducing twist strains the then exposing laser. theoretically analyzed influence of on spectra LPFGs, examined bend characteristics twisted (T-LPFGs). Experimental results showed that T-LPFGs exhibited clear spectra, insertion loss, polarization-dependent loss (PDL) compared conventional...

A high sensitivity, simple fabrication all-fibre strain sensor is proposed and demonstrated experimentally. The consists of a section Panda-type polarization maintaining fibre (PMF) built into Sagnac interferometer. PMF intentionally spliced to the single-mode through enhanced fusion splicing excite high-order polarized modes. characterizes large magnitude overlap. measured sensitivity reaches up 32 pm/με resolution 0.63 με has been achieved. characterizing easy can be good candidate in...

A surface plasmon resonance photonic crystal fiber-based highly sensitive temperature sensor is proposed. The induced by injecting toluene into the central hole and ethanol side holes coated with gold film. Optimal sensitivity optimizing size position of air holes. coupling mechanism sensing performance proposed are analyzed. results indicate that in range 0 °C−70 °C, highest figure merit (FOM) 0.1169/°C average can reach 7.13 nm/°C. Such exhibits tremendous potential domain detection.

A novel tunable comb filter composed of a single-mode/multimode/polarization-maintaining-fiber-based Sagnac fiber loop is proposed and experimentally demonstrated. The tunability achieved by rotating the polarization controller. spectral shift dependent on rotation direction position In addition, adjustable range half-wave-plate controller twice higher than that quarter-wave-plate one.

To analyze the mutations in transcription regulatory sequences (TRSs) of coronaviruss (CoV) to provide basis for exploring patterns SARS-CoV-2 transmission and outbreak.A combined evolutionary molecular functional analysis all sets publicly available genomic data viruses was performed.A leader sequence (TRS-L) usually comprises first 60-70 nts 5' UTR a CoV genome, body (TRS-Bs) are located immediately upstream genes other than ORF1a 1b. In each TRS-L TRS-Bs share specific consensus sequence,...

An interferometric bending sensor based on polarization-maintaining fiber (PMF) in combination with multi-mode (MMF) is proposed and demonstrated experimentally. One end of MMF was fusion spliced to PMF, the other single mode (SMF) pigtail a 3 dB optical coupler core offset. stress zone lead-out Panda type PMF intentionally aligned SMF enhance coupling. A pronounced interference pattern fringe contrast 28.1 obtained, sensitivity 18.66nm/m-1 achieved Such easy fabrication could be potential...