A novel single-mode single-polarization （SMSP） photonic crystal fibre has been proposed and analysed based on the polarization-dependent coupling and absorption effect via a full-vector finite element method with pe...A novel single-mode single-polarization （SMSP） photonic crystal fibre has been proposed and analysed based on the polarization-dependent coupling and absorption effect via a full-vector finite element method with perfectly matched layers. The numerical results predict that very efficient SMSP operation can be achieved with both high bandwidth and high extinction ratio at low loss penalty. Effects of the fibre structural parameters on the SMSP bandwidth and extinction ratio have been explored, which will provide useful guide for the design and fabrication of the fibre. The results obtained will be instructive for the realization of new SMSP fibres with high performance.展开更多
A type of photonic crystal fiber based on Kagome lattice cladding and slot air holes in a rectangular core is investigated. Full vector finite element method is used to evaluate the modal and propagation properties of...A type of photonic crystal fiber based on Kagome lattice cladding and slot air holes in a rectangular core is investigated. Full vector finite element method is used to evaluate the modal and propagation properties of the designed fiber.High birefringence of 0.089 and low effective material loss of 0.055 cm^-1 are obtained at 1 THz. The y-polarized fundamental mode of the designed fiber shows a flattened and near-zero dispersion of 0±0.45 ps · THz^-1· cm^-1 within a broad frequency range(0.5 THz–1.5 THz). Our results provide the theory basis for applications of the designed fiber in terahertz polarization maintaining systems.展开更多
Tuberculosis is one of the most contagious and lethal illnesses in the world,according to the World Health Organization.Tuberculosis had the leading mortality rate as a result of a single infection,ranking above HIV/A...Tuberculosis is one of the most contagious and lethal illnesses in the world,according to the World Health Organization.Tuberculosis had the leading mortality rate as a result of a single infection,ranking above HIV/AIDS.Early detection is an essential factor in patient treatment and can improve the survival rate.Detection methods should have high mobility,high accuracy,fast detection,and low losses.This work presents a novel biomedical photonic crystal fiber sensor,which can accurately detect and distinguish between the different types of tuberculosis bacteria.The designed sensor detects these types with high relative sensitivity and negligible losses compared to other photonic crystal fiber-based biomedical sensors.The proposed sensor exhibits a relative sensitivity of 90.6%,an effective area of 4.342×10^(-8)m^(2),with a negligible confinement loss of 3.13×10^(-9)cm^(-1),a remarkably low effective material loss of 0.0132cm-f,and a numerical aperture of 0.3462.The proposed sensor is capable of operating in the terahertz regimes over a wide range(1 THz-2.4 THz).An abbreviated review of non-optical detection techniques is also presented.An in-depth comparison between this work and recent related photonic crystal fiber-based literature is drawn to validate the efficacy and authenticity of the proposed design.展开更多
We present a review of the development of a compact and high-power broadband terahertz （THz） source optically excited by a femtosecond photonic crystal fiber （PCF） amplifier.The large mode area of the PCF and the ...We present a review of the development of a compact and high-power broadband terahertz （THz） source optically excited by a femtosecond photonic crystal fiber （PCF） amplifier.The large mode area of the PCF and the stretcher-free configuration make the pump source compact and very efficient.Broadband THz pulses of 150 μW extending from 0.1 to 3.5 THz are generated from a 3-mm-thick GaP crystal through optical rectification of 12-W pump pulses with duration of 66 fs and a repetition rate of 52 MHz.A strong saturation effect is observed,which is attributed to pump pulse absorption;a Z-scan measurement shows that three-photon absorption dominates the nonlinear absorption when the crystal is pumped by femtosecond pulses at 1 040 nm.A further scale-up of the THz source power is expected to find important applications in THz nonlinear optics and nonlinear THz spectroscopy.展开更多
This paper summarizes the recent progress in Terahertz(THz) waveguides. Many THz waveguides of various sorts have been presented and examined, including dielectric THz waveguides, metal THz waveguides, THz fiber and p...This paper summarizes the recent progress in Terahertz(THz) waveguides. Many THz waveguides of various sorts have been presented and examined, including dielectric THz waveguides, metal THz waveguides, THz fiber and photonic crystal THz waveguides. Their advantages and limitations are stated, and the perspective of research on Terahertz waveguides is discussed.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60372100 and 60507007）, and the State Key Development Program for Basic Research of China （Grant No 2003CB314906）.Acknowledgment The first author Liu Xiao-Yi would like to thank professor Yu Chong-Xiu for her constant encouragement and kind support.
文摘A novel single-mode single-polarization （SMSP） photonic crystal fibre has been proposed and analysed based on the polarization-dependent coupling and absorption effect via a full-vector finite element method with perfectly matched layers. The numerical results predict that very efficient SMSP operation can be achieved with both high bandwidth and high extinction ratio at low loss penalty. Effects of the fibre structural parameters on the SMSP bandwidth and extinction ratio have been explored, which will provide useful guide for the design and fabrication of the fibre. The results obtained will be instructive for the realization of new SMSP fibres with high performance.
基金Project supported by the National Natural Science Foundation of China(Grant No.11604260)the Outstanding Youth Science Fund of Xi’an University of Science and Technology,China(Grant No.2019YQ3-10)
文摘A type of photonic crystal fiber based on Kagome lattice cladding and slot air holes in a rectangular core is investigated. Full vector finite element method is used to evaluate the modal and propagation properties of the designed fiber.High birefringence of 0.089 and low effective material loss of 0.055 cm^-1 are obtained at 1 THz. The y-polarized fundamental mode of the designed fiber shows a flattened and near-zero dispersion of 0±0.45 ps · THz^-1· cm^-1 within a broad frequency range(0.5 THz–1.5 THz). Our results provide the theory basis for applications of the designed fiber in terahertz polarization maintaining systems.
文摘Tuberculosis is one of the most contagious and lethal illnesses in the world,according to the World Health Organization.Tuberculosis had the leading mortality rate as a result of a single infection,ranking above HIV/AIDS.Early detection is an essential factor in patient treatment and can improve the survival rate.Detection methods should have high mobility,high accuracy,fast detection,and low losses.This work presents a novel biomedical photonic crystal fiber sensor,which can accurately detect and distinguish between the different types of tuberculosis bacteria.The designed sensor detects these types with high relative sensitivity and negligible losses compared to other photonic crystal fiber-based biomedical sensors.The proposed sensor exhibits a relative sensitivity of 90.6%,an effective area of 4.342×10^(-8)m^(2),with a negligible confinement loss of 3.13×10^(-9)cm^(-1),a remarkably low effective material loss of 0.0132cm-f,and a numerical aperture of 0.3462.The proposed sensor is capable of operating in the terahertz regimes over a wide range(1 THz-2.4 THz).An abbreviated review of non-optical detection techniques is also presented.An in-depth comparison between this work and recent related photonic crystal fiber-based literature is drawn to validate the efficacy and authenticity of the proposed design.
基金supported partly by the National Natural Science Foundation of China (Nos. 61077083, 61027013,61078028,and 60838004)the National Basic Research Program of China (Nos. 2007CB310408, 2010CB327604,and 2011CB808101)+3 种基金the Research Fund for the Doctoral Program of Higher Education (No. 200800560026)the Foundation for the Author of National Excellent Doctoral Dissertation of China (No. 2007B34)the 111 Project (No. B07014)the Program for New Century Talents in University (No. NCET-07-0597)
文摘We present a review of the development of a compact and high-power broadband terahertz （THz） source optically excited by a femtosecond photonic crystal fiber （PCF） amplifier.The large mode area of the PCF and the stretcher-free configuration make the pump source compact and very efficient.Broadband THz pulses of 150 μW extending from 0.1 to 3.5 THz are generated from a 3-mm-thick GaP crystal through optical rectification of 12-W pump pulses with duration of 66 fs and a repetition rate of 52 MHz.A strong saturation effect is observed,which is attributed to pump pulse absorption;a Z-scan measurement shows that three-photon absorption dominates the nonlinear absorption when the crystal is pumped by femtosecond pulses at 1 040 nm.A further scale-up of the THz source power is expected to find important applications in THz nonlinear optics and nonlinear THz spectroscopy.
文摘This paper summarizes the recent progress in Terahertz(THz) waveguides. Many THz waveguides of various sorts have been presented and examined, including dielectric THz waveguides, metal THz waveguides, THz fiber and photonic crystal THz waveguides. Their advantages and limitations are stated, and the perspective of research on Terahertz waveguides is discussed.
