We propose a novel waveguide design of polarization-maintaining few mode fiber(PM-FMF) supporting ≥10non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure ...We propose a novel waveguide design of polarization-maintaining few mode fiber(PM-FMF) supporting ≥10non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure endows a new degree of freedom to adjust the birefringence of all the guided modes, including the fundamental polarization mode. Numerical simulations demonstrate that, by optimizing the air hole and elliptical-ring core,a PM-FMF supporting 10 distinctive polarization modes has been achieved, and the effective index difference Δn_(eff) between the adjacent guided modes could be kept larger than 1.32 × 10^(-4) over the whole C +L band. The proposed fiber structure can flexibly tailored to support an even larger number of modes in PM-FMF(14-mode PM-FMF has been demonstrated as an example), which can be readily applicable to a scalable mode division multiplexing system.展开更多
A high-sensitivity all-fiber temperature sensor based on a Sagnac interferometer is demonstrated by splicing a section of polarization maintaining fiber(PMF)between two sections of standard single mode fibers(SMFs).In...A high-sensitivity all-fiber temperature sensor based on a Sagnac interferometer is demonstrated by splicing a section of polarization maintaining fiber(PMF)between two sections of standard single mode fibers(SMFs).In this sensor,the SMF-PMF-SMF structure in the Sagnac loop is bent into a circle to enhance the sensitivity.The length and curvature of the PMF in the loop are investigated and can be optimized to further increase the temperature sensitivity of the sensor. Results show that the radius of the circle has an important effect upon temperature sensitivity due to the bend-induced birefringence variation of the PMF.The SMF-PMF-SMF structure bent into a circle with a radius of 30mm exhibits a high-sensitivity temperature of 1.73nm/℃.The sensor is provided with the advantages of easy fabrication,low-insertion loss,and high sensitivity,which may find potential applications in the field of high precision temperature measurement.展开更多
We present a polarization-maintaining PANDA ring-core fiber(PM-PRCF) characterized by the combination of a ring-core structure with two stress-applying rods. This special fiber design separates the adjacent modes and ...We present a polarization-maintaining PANDA ring-core fiber(PM-PRCF) characterized by the combination of a ring-core structure with two stress-applying rods. This special fiber design separates the adjacent modes and avoids the cutoff of the higher-order modes, which is a common problem in elliptical core polarization-maintaining few-mode fibers. Using a high-contrast index ring and stress-induced birefringence, the PM-PRCF features support for 10 vector modes, with effective refractive index separations from their adjacent modes >10^(-4).Broadband performance is investigated subsequently over a wide wavelength range from 1500 to 1630 nm.The proposed fiber is targeted at applications in space-division multiplexing while eliminating the complex multiple-input multiple-output signal processing.展开更多
Ground-satellite quantum key distribution(QKD)is a feasible way to implement global-scale quantum communication.Herein we propose an approach to dynamically compensate the polarization of the photons when passing thro...Ground-satellite quantum key distribution(QKD)is a feasible way to implement global-scale quantum communication.Herein we propose an approach to dynamically compensate the polarization of the photons when passing through the optical telescope used in ground-satellite QKD.Our results experimentally demonstrate that the fidelity of any polarization state after dynamic compensation can be achieved by more than 99.5%,which fulfills the requirements of ground-satellite QKD.展开更多
We demonstrate an all polarization-maintaining(PM) fiber mode-locked laser seeded, hybrid fiber/solid-slab picosecond pulse laser system which outputs 40 μJ, 10 ps pulses at the central wavelength of 1064 nm. The bea...We demonstrate an all polarization-maintaining(PM) fiber mode-locked laser seeded, hybrid fiber/solid-slab picosecond pulse laser system which outputs 40 μJ, 10 ps pulses at the central wavelength of 1064 nm. The beam quality factors M2 in the unstable and stable directions are 1.35 and 1.31, respectively. 15 μJ picosecond pulses at the central wavelength of 355 nm are generated through third harmonic generation(THG) by using two Li B3 O5(LBO) crystals, in order to get better processing efficiency on polycrystalline diamonds. The high pulse energy and beam quality of these ultraviolet(UV) picosecond pulses are confirmed by latter experiments of material processing on polycrystalline diamonds. This scheme which combines the advantages of the all PM fiber mode-locked laser and the solid-slab amplifier enables compact, robust and chirped pulse amplification-free amplification with high power picosecond pulses.展开更多
We demonstrate an all-polarization-maintaining(APM)fiber mode-locked laser based on nonlinear polarization evolution(NPE).A well-designed Sagnac fiber loop is employed to establish the nonlinear polarization evolution...We demonstrate an all-polarization-maintaining(APM)fiber mode-locked laser based on nonlinear polarization evolution(NPE).A well-designed Sagnac fiber loop is employed to establish the nonlinear polarization evolution process in a polarization beam splitter(PBS)figure-8 fiber laser.Nonlinear loss curves are calculated to verify the saturable absorption characteristic of this NPE-based APM oscillator.Then,we simulate the pulse propagation process in the cavity to demonstrate the pulse mode-locked formation.Finally,we also design a realizable compact scheme to further reduce noise disturbances,achieving a 101-fs mode-locked pulse train with a 0.3-mrad integrated phase noise and a 0.006%integrated relative intensity noise(RIN).This figure-8 fiber laser provides a new scheme for compacting low-noise compact APM fiber lasers based on the NPE mode-locked mechanism.展开更多
We experimentally demonstrated a stable multi-wavelength bright-dark pulse pair in a mode-locked thulium-doped fiber laser(TDFL).The nonlinear polarization rotation(NPR)and nonlinear optical loop mirror(NOLM)were empl...We experimentally demonstrated a stable multi-wavelength bright-dark pulse pair in a mode-locked thulium-doped fiber laser(TDFL).The nonlinear polarization rotation(NPR)and nonlinear optical loop mirror(NOLM)were employed in a figure-eight cavity to allow for multi-wavelength mode-locking operation.By incorporating different lengths of high birefringence polarization-maintaining fiber(PMF),the fiber laser could operate stably in a multi-wavelength emission state.Compared with the absence of the PMF,the birefringence effect caused by PMF resulted in rich multi-wavelength optical spectra and better intensity symmetry and stability of the bright-dark pulse pair.展开更多
We demonstrate an all-fiber high-power linearly polarized supercontinuum source with polarization-maintaining photonic crystal fibers(PM-PCFs)as the nonlinear medium.The source exhibits an average output power of 3.8 ...We demonstrate an all-fiber high-power linearly polarized supercontinuum source with polarization-maintaining photonic crystal fibers(PM-PCFs)as the nonlinear medium.The source exhibits an average output power of 3.8 W with a flat spectrum from 480 nm to 2100 nm at the-10 dB level,except for the residual pump peak.The polarization extinction ratio(PER)is measured to be greater than 20 dB at selected sample wavelength points(532 nm,1064 nm and 1550 nm)at the highest pump power level and greater than 20 dB at all wavelengths from 800 nm to 1500 nm at the low pump power level.We also experimentally study the spectral properties when the pump light propagates along different axes of the PM-PCF.The results show that propagating parallel to the slow axis enables a broader spectrum in the PM-PCF in this case,probably due to matching of the dispersion properties with the pump light,which is qualitatively in accordance with the numerical simulation.To our best knowledge,this is the first demonstration of a watt-level linearly polarized supercontinuum source generated from PM-PCFs in an all-fiber structure.展开更多
A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polari...A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polarization controller(PC),and a circulator with four ports was used to suppress the mode competition.The light transmission direction was guaranteed by the circulator.For the proposed fiber laser,tunable single,dual,triple,quadruple,quintuple,sextuple,and septuple wavelengths were realized.A single-wavelength laser output with an optical signal-to-noise ratio(SNR)of up to30.56 dB was realized,and a tuning range of 1590.54 nm to 1599.54 nm was achieved by tuning the PC.The stability of the single,dual,triple,and quadruple-wavelength center power fluctuations was less than 0.05 dB,0.98 dB,5.07 dB,and7.71 dB respectively.When the laser was operated in the multiwavelength condition,the SNR was more than 20.97 dB.The proposed erbium-doped fiber laser is suitable for fiber-sensing system applications.展开更多
基金National Natural Science Foundation of China(NSFC)(61331010,61205063)863 High Technology plan(2015AA016904)Program for New Century Excellent Talents in University(NCET)(NCET-13-0235)
文摘We propose a novel waveguide design of polarization-maintaining few mode fiber(PM-FMF) supporting ≥10non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure endows a new degree of freedom to adjust the birefringence of all the guided modes, including the fundamental polarization mode. Numerical simulations demonstrate that, by optimizing the air hole and elliptical-ring core,a PM-FMF supporting 10 distinctive polarization modes has been achieved, and the effective index difference Δn_(eff) between the adjacent guided modes could be kept larger than 1.32 × 10^(-4) over the whole C +L band. The proposed fiber structure can flexibly tailored to support an even larger number of modes in PM-FMF(14-mode PM-FMF has been demonstrated as an example), which can be readily applicable to a scalable mode division multiplexing system.
基金the National Natural Science Foundation of China(NSFC)(Grant Nos.61425007 and 61635007)Guangdong Natural Science Foundation(Grant Nos.2015B010105007 and 2014A030308007)+3 种基金Science and Technology Innovation Commission of Shenzhen(Grant Nos.JCYJ20170412105604705 and JCYJ20160427104925452)Development and Reform Commission of Shenzhen Municipality Foundationthe National Natural Science Foundation of China(Grant No.61565002)Guangxi Province Key Research and Development Program(Grant No.AB171129027).
文摘A high-sensitivity all-fiber temperature sensor based on a Sagnac interferometer is demonstrated by splicing a section of polarization maintaining fiber(PMF)between two sections of standard single mode fibers(SMFs).In this sensor,the SMF-PMF-SMF structure in the Sagnac loop is bent into a circle to enhance the sensitivity.The length and curvature of the PMF in the loop are investigated and can be optimized to further increase the temperature sensitivity of the sensor. Results show that the radius of the circle has an important effect upon temperature sensitivity due to the bend-induced birefringence variation of the PMF.The SMF-PMF-SMF structure bent into a circle with a radius of 30mm exhibits a high-sensitivity temperature of 1.73nm/℃.The sensor is provided with the advantages of easy fabrication,low-insertion loss,and high sensitivity,which may find potential applications in the field of high precision temperature measurement.
基金973 Program(2014CB340003)National Natural Science Foundation of China(NSFC)(61307081,61321004,61420106003)
文摘We present a polarization-maintaining PANDA ring-core fiber(PM-PRCF) characterized by the combination of a ring-core structure with two stress-applying rods. This special fiber design separates the adjacent modes and avoids the cutoff of the higher-order modes, which is a common problem in elliptical core polarization-maintaining few-mode fibers. Using a high-contrast index ring and stress-induced birefringence, the PM-PRCF features support for 10 vector modes, with effective refractive index separations from their adjacent modes >10^(-4).Broadband performance is investigated subsequently over a wide wavelength range from 1500 to 1630 nm.The proposed fiber is targeted at applications in space-division multiplexing while eliminating the complex multiple-input multiple-output signal processing.
基金supported by the National Natural Science Foundation of China(Grant No.11274296)Zhejiang Provincial Natural Science Foundation of China(Grant No.LY13F050007)K.C.Wong Magna Fund in Ningbo University
文摘Ground-satellite quantum key distribution(QKD)is a feasible way to implement global-scale quantum communication.Herein we propose an approach to dynamically compensate the polarization of the photons when passing through the optical telescope used in ground-satellite QKD.Our results experimentally demonstrate that the fidelity of any polarization state after dynamic compensation can be achieved by more than 99.5%,which fulfills the requirements of ground-satellite QKD.
基金supported by the National Natural Science Foundation of China(Nos.61535009,11527808,61605142,and 61735007)the Tianjin Research Program of Application Foundation and Advanced Technology(No.17JCJQJC43500)
文摘We demonstrate an all polarization-maintaining(PM) fiber mode-locked laser seeded, hybrid fiber/solid-slab picosecond pulse laser system which outputs 40 μJ, 10 ps pulses at the central wavelength of 1064 nm. The beam quality factors M2 in the unstable and stable directions are 1.35 and 1.31, respectively. 15 μJ picosecond pulses at the central wavelength of 355 nm are generated through third harmonic generation(THG) by using two Li B3 O5(LBO) crystals, in order to get better processing efficiency on polycrystalline diamonds. The high pulse energy and beam quality of these ultraviolet(UV) picosecond pulses are confirmed by latter experiments of material processing on polycrystalline diamonds. This scheme which combines the advantages of the all PM fiber mode-locked laser and the solid-slab amplifier enables compact, robust and chirped pulse amplification-free amplification with high power picosecond pulses.
基金supported by the National Natural Science Foundation of China(Nos.12204178,12134004,12104162,and 12274141).
文摘We demonstrate an all-polarization-maintaining(APM)fiber mode-locked laser based on nonlinear polarization evolution(NPE).A well-designed Sagnac fiber loop is employed to establish the nonlinear polarization evolution process in a polarization beam splitter(PBS)figure-8 fiber laser.Nonlinear loss curves are calculated to verify the saturable absorption characteristic of this NPE-based APM oscillator.Then,we simulate the pulse propagation process in the cavity to demonstrate the pulse mode-locked formation.Finally,we also design a realizable compact scheme to further reduce noise disturbances,achieving a 101-fs mode-locked pulse train with a 0.3-mrad integrated phase noise and a 0.006%integrated relative intensity noise(RIN).This figure-8 fiber laser provides a new scheme for compacting low-noise compact APM fiber lasers based on the NPE mode-locked mechanism.
基金the National Natural Science Foundation of China(Grant No.6170031626)the Natural Science Foundation of Chongqing City,China(Grant Nos.cstc2018jcyjAX0585 and cstc2017zdzxX0011).
文摘We experimentally demonstrated a stable multi-wavelength bright-dark pulse pair in a mode-locked thulium-doped fiber laser(TDFL).The nonlinear polarization rotation(NPR)and nonlinear optical loop mirror(NOLM)were employed in a figure-eight cavity to allow for multi-wavelength mode-locking operation.By incorporating different lengths of high birefringence polarization-maintaining fiber(PMF),the fiber laser could operate stably in a multi-wavelength emission state.Compared with the absence of the PMF,the birefringence effect caused by PMF resulted in rich multi-wavelength optical spectra and better intensity symmetry and stability of the bright-dark pulse pair.
文摘We demonstrate an all-fiber high-power linearly polarized supercontinuum source with polarization-maintaining photonic crystal fibers(PM-PCFs)as the nonlinear medium.The source exhibits an average output power of 3.8 W with a flat spectrum from 480 nm to 2100 nm at the-10 dB level,except for the residual pump peak.The polarization extinction ratio(PER)is measured to be greater than 20 dB at selected sample wavelength points(532 nm,1064 nm and 1550 nm)at the highest pump power level and greater than 20 dB at all wavelengths from 800 nm to 1500 nm at the low pump power level.We also experimentally study the spectral properties when the pump light propagates along different axes of the PM-PCF.The results show that propagating parallel to the slow axis enables a broader spectrum in the PM-PCF in this case,probably due to matching of the dispersion properties with the pump light,which is qualitatively in accordance with the numerical simulation.To our best knowledge,this is the first demonstration of a watt-level linearly polarized supercontinuum source generated from PM-PCFs in an all-fiber structure.
基金Beijing Great Wall Scholars Program(Grant No.CIT&TCD20190323)Beijing Youth Talent Support Program(Grant No.Z2019042)the National Natural Science Foundation of China(Grant No.61875237).
文摘A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polarization controller(PC),and a circulator with four ports was used to suppress the mode competition.The light transmission direction was guaranteed by the circulator.For the proposed fiber laser,tunable single,dual,triple,quadruple,quintuple,sextuple,and septuple wavelengths were realized.A single-wavelength laser output with an optical signal-to-noise ratio(SNR)of up to30.56 dB was realized,and a tuning range of 1590.54 nm to 1599.54 nm was achieved by tuning the PC.The stability of the single,dual,triple,and quadruple-wavelength center power fluctuations was less than 0.05 dB,0.98 dB,5.07 dB,and7.71 dB respectively.When the laser was operated in the multiwavelength condition,the SNR was more than 20.97 dB.The proposed erbium-doped fiber laser is suitable for fiber-sensing system applications.
