High Birefringence Photonic Crystal Fiber Research Articles

High-birefringence photonic crystal fiber Michelson interferometer with cascaded fiber Bragg grating for pressure and temperature discrimination

A simple and compact interferometer for temperature and pressure discrimination is proposed and demonstrated experimentally. It consists of a short section of high-birefringence photonic crystal fiber (Hi-Bi PCF) and a cascaded fiber Bragg grating (FBG). In the Hi-Bi PCF, two orthogonal polarized modes are employed as optical arms to construct, such as a Michelson interferometer. Combined with a cascaded FBG, pressure and temperature measurements are discriminated by a matrix method, and the pressure sensitivity of Hi-Bi PCF is determined to be around 3.65 nm/MPa. The proposed Michelson interferometer is easy-to-fabricate, flexible, and low-cost, which shows great potential in future applications of remote sensing.

Magnetic Field Measurement Based on the Sagnac Interferometer With a Ferrofluid-Filled High-Birefringence Photonic Crystal Fiber

A compact optical fiber magnetic field sensor based on the principle of the Sagnac interferometer is proposed. Different from the conventional ones, a ferrofluid-filled high-birefringence photonic crystal fiber (HB-PCF) is inserted into the Sagnac as a magnetic field sensing element. The refractive index of the ferrofluid filled in the cladding air holes of the HB-PCF will change with respect to the applied magnetic field, and subsequently, the birefringence of the HB-PCF will change, which will affect the shifts of the output interference spectrum in Sagnac. Experiments are carried out to verify the simulation model and the results indicate that the interference spectrum exhibits a red shift with the increment in the magnetic field intensity. The sensitivity of the proposed sensor is up to 0.073 nm/mT for a magnetic field intensity ranging from 10 to 40 mT, while the resolution is 0.001 mT. The proposed magnetic field sensor is attractive due to its compact size, low cost, and immunity to electromagnetic interference beyond what conventional magnetic field sensors can offer.

Tunable microwave generation method based on birefringence photonic crystal fiber

A new method is proposed to generate tunable microwave by using single-light source and birefringence photonic crystal fiber (PCF), which is based on the interaction and the coupling between the two polarizations of the initial Gaussian optical pulse in PCF. A full vector finite element is used to design a high birefringence PCF. The expressions of the microwave are derived by couple-mode theory. The proof of concept device consists of a light source, a birefringence PCF, a polarizer controller and a photodetector. The frequency of the generated pulses can be controlled by adjusting the parameters of the optical fiber system. The simulation results demonstrate the system can generate the frequency of microwave are 8.03–37.67GHz and 26.82–125.5GHz from two kinds of PCFs, respectively. The system is elastic, stable, brief and highly efficient.

High-birefringence photonic crystal fiber polarization filter based on surface plasmon resonance.

In this paper, we designed a C2v-symmetry-structured photonic crystal fiber with triangular lattice and Au-filled air holes. The finite element method is used to analyze the dispersion and confinement loss characteristics of the core mode and the surface plasmon mode of the metal wire. In this work, we found that the positions of resonance peaks and the resonance strength of core mode and surface plasmon mode can be well adjusted by changing the pitch between the cladding air holes and the diameters of the air holes or metal wires around the core. By optimizing the parameters of the fiber structure, a polarization filter at the communication band is designed. At the wavelength of 1.31 μm, which is located in the communication band, the fundamental mode in X pol can be filtered with the diameter of the metal wire d(m)=1.2 μm. When d(m)=1.4 μm, the fundamental mode in Y pol can be filtered at the wavelength of 1.55 μm, which is also located in the communication band. Compared with the ordinary single-polarization and single-mode photonic crystal fiber, the fiber we proposed in this paper can selectively filter out the polarized light in one direction by adjusting the wire diameter. It is meaningful for the development of the polarization filter in the communication band.

一种高双折射高负平坦色散压缩型光子晶体光纤

一种高双折射高负平坦色散压缩型光子晶体光纤

一种高双折射高负平坦色散压缩型光子晶体光纤

一种高双折射高负平坦色散压缩型光子晶体光纤

一种高双折射高负平坦色散压缩型光子晶体光纤

A squeezed high birefringence Photonic Crystal Fiber (PCF) with high negative flattened dispersion characteristics was proposed. In order to obtain the high birefringence characteristics, the cladding of PCF was made of squeezed triangular lattice and elliptical air holes. In order to improve the flexibility of controlling the dispersion, the core of PCF was added into a small defect air hole. The birefringence and dispersion characteristics were analyzed by super lattice method. The simulation results show that the designed PCF offers ultra flattened negative dispersion (-6677 psnm-1km-1) in a broad range of wavelengths from 1.3 m to 1.8 m, the birefringence can be reached the magnitude of 10-2 and the high birefringence can be reached 2.2110-2 at 1.55 m. Based on the high negative dispersion and high birefringence characteristic, PCF will be widely used in optical transmission system and optical fiber sensing.

Numerical analysis of supercontinuum generation in high birefringent solid core photonic crystal fiber

A solid core high birefringent photonic crystal fiber (PCF) is designed for supercontinuum (SC) generation. The effective refractive index, effective area, nonlinear coefficient, birefringence and dispersion characteristics of the PCF are investigated using the finite element method. The birefringence value of this PCF reaches the magnitude of 10−3 which is required for high precision applications in optical systems. In order to study SC generation higher order dispersion terms and nonlinear coefficient of the birefringent PCF are calculated separately for both the orthogonally polarized modes. Numerical simulation of SC generation in the proposed PCF is analyzed using the coupled nonlinear Schrodinger equation and split step Fourier transform method. The results show that the SC generation in PCF is strongly affected by the input polarization angle, pulse duration, peak power and initial frequency chirp.

High birefringence photonic crystal fiber with high nonlinearity and low confinement loss.

A particular photonic crystal fiber (PCF) designed with all circle air holes is proposed. Its characteristics are studied by full-vector finite element method (FEM) with anisotropic perfectly matched layer (PML). The simulation results indicated that the proposed PCF can realize high birefringence (up to 10(-2)), high nonlinearity (50W(-1)·km(-1) and 68W(-1)·km(-1) in X and Y polarizations respectively) and low confinement loss (less than 10(-3)dB/km at 1.55um wavelength).

基于CdSe/ZnS量子点薄膜结构的高双折射光子晶体光纤的色散与损耗控制

基于CdSe/ZnS量子点薄膜结构的高双折射光子晶体光纤的色散与损耗控制

Photonic Crystal Fiber Loop Mirror-Based Chemical Vapor Sensor

A compact chemical vapor sensor based on a fiber loop mirror (FLM) inserted with a high-birefringent photonic crystal fiber (HiBi-PCF) is proposed and experimentally demonstrated. Because the resonant dips of the HiBi-PCF FLM are sensitive to the phase difference between two counter-propagating waves in the FLM, a highly sensitive chemical vapor can be achieved by measuring the resonant dip shifts when chemical vapor diffuses into the air holes of the HiBi-PCF. Experimental results show a high sensitivity of 15.5 pm/ppm for ethanol is obtained when a 5.1 cm long HiBi-PCF is used in the FLM. Three different mechanisms for the high sensitivity of the proposed sensor are discussed. A liquefaction model with a full-vector finite element method is proposed and is regarded as the main contribution.

Broadband optical gain in the normally dispersive region of a high-birefringence photonic crystal fiber

Based on a designed high-birefringence photonic crystal fiber (HB-PCF) with two zero-dispersion wavelengths (ZDWs), the effect of pump parameters and Raman scattering on the modulation instability (MI) gain is comprehensively analyzed in this paper. An interesting result is found, in that only when the pump wavelength lies within an approximately 10 nm range of the zero-dispersion points in the normal dispersion region of the HB-PCF does a broadband gain characteristic appear. The Raman effect results in a combination of the gain spectra from the Stokes and anti-Stokes band, which finally promotes the formation of broadband amplification. Moreover, there exist an optimal pump wavelength and a suitable pump power along the fast axis or the slow axis of the fiber. With these optimal pump parameters, the total MI gain bandwidth finally reaches 159 nm for the fiber fast axis and 162 nm for the fiber slow axis.

Experimental research on FLM temperature sensor with an ethanol-filled photonic crystal fiber

A compact optical fiber temperature sensor based on the principle of fiber loop mirror (FLM) was proposed. Different from the conventional ones, an ethanol-filled high birefringence photonic crystal fiber (HB-PCF) is inserted into the FLM as a temperature sensing element. Two structures based on the FLM were designed, one is to insert a short length of ethanol-filled HB-PCF in the FLM, and the other is to make a reflective probe with the ethanol-filled HB-PCF, since the independent probe is more suitable for practical application. The refractive index of the ethanol filled in the cladding air holes of HB-PCF would change versus the applied temperature, and the birefringence of the HB-PCF would change as well, which would affect the output wavelength shifts of the FLM. Experiments were carried out to verify the sensor principle. Preliminary experimental results indicated that the temperature sensitivity of the two structures were 0.8833nm/°C and 0.7896nm/°C, respectively, for a 10-cm-long HB-PCF.

一种基于肖特玻璃的新型高双折射光子晶体光纤

A novel design of high birefringent photonic crystal fiber based on schott glass with elliptical air holes in the core and cladding is proposed,and two circular air holes are introduced in the innermost layer of the cladding.Using the finite element method,its birefringence,confinement loss and dispersion characteristics are investigated simultaneously by changing the pitch of air holes and ellipticity of elliptic air holes.Numerical results show that the value of birefringence can be improved by introducing a small elliptical air hole in the core,the birefringence and confinement loss are respectively about 5.22×10-2 and8.82×10-10 dB/m at 1.55μm with the cladding air holes pitch size of 1.6μm and the ellipticity ratio of0.5.In addition,the fiber keeps normal dispersion in a wavelength range from 1.0μm to 2.2μm.In conclusion,this proposed photonic crystal fiber are significant for the further research on the new background material photonic crystal fiber.

Research on terahertz photonic crystal fiber characteristics with high birefringence

A new high birefringence photonic crystal fiber is proposed within the terahertz frequency region. It has two types of claddings, the inner is composed of six ellipse air holes arranged in a honeycomb array and the outer surrounded by circle holes. By using the full vector finite element method with anisotropic perfectly matched layers absorption boundary condition, the birefringence, chromatic dispersion and confinement loss of the fundamental mode are evaluated. The results show that the birefringence can achieve 10−3 when the wavelength increases from 600μm to 900μm. This structure will provide some reference value for the designing of high birefringence terahertz photonic crystal fiber.

A Novel High-Birefringent Photonic Crystal Fiber and its Polarization Maintaining Properties

A novel high-birefringent photonic crystal fiber (PCF) was proposed and analyzed by full-vector finite element method (FEM). The modal field and birefringence properties were investigated. All of air holes in proposed PCF are round, and their diameters are the same. It is greatly reduce the difficulty of fabrication. According to the results of numerical analysis, it can be observed that the mode birefringence of this novel PCF can be easily achieve the order of 10-3 at 1.55μm. This research provides effective theoretical method for the fabrication, development and construction of high-birefringence photonic crystal fiber.

Analysis of high birefringence photonic crystal fiber with octagonal and squarely lattice

Aiming at the requirement of high birefringence, a new kind of photonic crystal fiber (PCF) with octagonal and squarely lattice is proposed. In this structure, squarely lattices are added in the inner layer to obtain high birefringence. Birefringence and dispersion as a function of wavelength and size of PCF are analyzed by using Finite Element Method (FEM). Simulation results show that this kind of PCF exhibits high birefringence with a magnitude of 10−3, and one zero dispersion point is obtained simultaneously. In addition, the characteristics of PCF can be tuned by changing the size of fiber.

Broadband tunable optical amplification based on modulation instability characteristic of high-birefringence photonic crystal fibers

A novel high-birefringence photonic crystal fiber (HB-PCF) with two zero-dispersion wavelengths (ZDWs) is designed, and an extraordinarily high modal birefringence of 1.56×10−2 is obtained at pump wavelength λp = 1850 nm. With the designed HB-PCF, the effect of the pump parameters on the modulation instability (MI) in the anomalous dispersion region close to the second ZDWs of the HB-PCF is comprehensively studied in this work. A broadband and tunable optical amplification is achieved by controlling the pump power and the pump wavelength based on the combined operation of Raman effect and cross phase modulation. By optimizing the pump parameters, the amplification bandwidth along the fiber slow axis reaches 152 nm for the pump power Pp = 280 W and the pump wavelength λp=1675 nm, while the gain bandwidth along the fiber fast axis is 165 nm for the pump power Pp = 600 W and the pump wavelength λp = 1818 nm.

Broadband modulation instability gain in a high-birefringence photonic crystal fiber with two zero-dispersion wavelengths

Based on a designed high-birefringence photonic crystal fiber with two zero-dispersion wavelengths (ZDWs), the effect of fiber dispersion, pump power and pump wavelength on the modulation instability (MI) gain in the anomalous dispersion region is comprehensively analyzed in this paper. An asymmetric and broadband MI gain spectrum appears at the anti-Stokes band due to the different ZDWs along the fiber slow- and fast-axes. An optimal MI gain can be obtained when the pump wavelength (1675 nm) is slightly shorter than the second ZDW (1683 nm) and the pump power is 280 W. The optimal MI gain bandwidth finally reaches 152 nm and the gain profile is smoother.

Multi-wavelength fiber laser in single-longitudinal mode operation using a photonic crystal fiber Sagnac interferometer

In this paper, we report a new configuration of a tunable multi-wavelength erbium-doped fiber laser based on the commercial optical multiplexers and a Sagnac interferometer which includes a section of a high-birefringent photonic crystal fiber. Four-wavelength laser emission lines were obtained simultaneously in single-longitudinal mode operation showing a power instability lower than 1 dB, and an optical signal-to-noise ratio higher than 65 dB for all the emitted wavelengths. This proposed configuration allows the individual control of the loss of each channel of the laser and because of it is based on the commercial ITU-grid multiplexers, the laser is adapted to the telecommunications channel’s normative.