Showing papers by "Shuisheng Jian published in 2014"
TL;DR: The proposed model provides a fast insight into the mode behavior of graphene-coated nanowire, which would be useful for applications based on graphene plasmonics in cylindrical waveguide.
Abstract: An analytical model for plasmon modes in graphene-coated dielectric nanowire is presented. Plasmon modes could be classified by the azimuthal field distribution characterized by a phase factor exp(imφ) in the electromagnetic field expression and eigen equation of dispersion relation for plasmon modes is derived. The characteristic of plasmon modes could be tuned by changing nanowire radius, dielectric permittivity of nanowire and chemical potential of graphene. The proposed model provides a fast insight into the mode behavior of graphene-coated nanowire, which would be useful for applications based on graphene plasmonics in cylindrical waveguide.
128 citations
TL;DR: By changing the Fermi level of graphene, the performance of the proposed waveguide could be tuned flexibly, offering potential application in tunable nanophotonic devices.
Abstract: We propose in this Letter a single-mode graphene-coated nanowire surface plasmon waveguide. The single-mode condition and modal cutoff wavelength of high order modes are derived from an analytic model and confirmed by numerical simulation. The mode number diagram of the proposed waveguide in the wavelength-radius space is also demonstrated. By changing the Fermi level of graphene, the performance of the proposed waveguide could be tuned flexibly, offering potential application in tunable nanophotonic devices.
94 citations
TL;DR: The refractive index (RI) characteristics of a singlemode-claddingless-singlemode fiber structure filter based fiber ring cavity laser sensing system is demonstrated and it is shown that the lasing wavelength shifts to red side with the ambient RI increase.
Abstract: This paper firstly demonstrated the refractive index (RI) characteristics of a singlemode-claddingless-singlemode fiber structure filter based fiber ring cavity laser sensing system. The experiment shows that the lasing wavelength shifts to red side with the ambient RI increase. Linear and parabolic fitting are both done to the measurements. The linear fitting result shows a good linearity for applications in some areas with the determination coefficient of 0.993. And a sensitivity of ~131.64nm/RIU is experimentally achieved with the aqueous solution RI ranging from 1.333 to 1.3707, which is competitively compared to other existing fiber-optic sensors. While the 2 order polynomial fitting function, which determination relationship is higher than 0.999, can be used to some more rigorous monitoring. The proposed fiber laser has a SNR of ~50dB, and 3dB bandwidth ~0.03nm.
59 citations
TL;DR: A tunable and switchable dual-wavelength single polarization narrow linewidth single-longitudinal-mode (SLM) erbium-doped fiber (EDF) ring laser based on polarization-maintaining chirped moiré fiber Bragg grating (PM-CMFBG) filter is proposed and demonstrated.
Abstract: A tunable and switchable dual-wavelength single polarization narrow linewidth single-longitudinal-mode (SLM) erbium-doped fiber (EDF) ring laser based on polarization-maintaining chirped moire fiber Bragg grating (PM-CMFBG) filter is proposed and demonstrated. For the first time as we know, the CMFBG inscribed on the PM fiber is applied for the wavelength-tunable and-switchable dual-wavelength laser. The PM-CMFBG filter with ultra-narrow transmission band (0.1 pm) and a uniform polarization-maintaining fiber Bragg grating (PM-FBG) are used to select the laser longitudinal mode. The stable single polarization SLM operation is guaranteed by the PM-CMFBG filter and polarization controller. A tuning range of about 0.25 nm with about 0.075 nm step is achieved by stretching the uniform PM-FBG. Meanwhile, the linewidth of the fiber laser for each wavelength is approximate 6.5 and 7.1 kHz with a 20 dB linewidth, which indicates the laser linewidth is approximate 325 Hz and 355 Hz FWHM.
55 citations
TL;DR: In this article, a fiber-optic strain and curvature sensor based on no-core fiber has been proposed and demonstrated, which is fabricated using a multimode fiber without cladding, known as the nocore fiber with a thinner diameter.
Abstract: A fiber-optic strain and curvature sensor based on no-core fiber has been proposed and demonstrated. The sensor is fabricated using a multimode fiber without cladding, known as the no-core fiber with a thinner diameter. The jointing point between the no-core fiber and single-mode fiber is a taper, which will improve the sensitivity of the sensor. The peak wavelength shift of the sensor exhibits an excellent response for strain and curvature changes.
41 citations
TL;DR: In this paper, a novel refractive index (RI) and temperature all-fiber ring laser sensor based on singlemode-tapered claddingless-singlemode (STCS) fiber structure is proposed and experimentally demonstrated.
Abstract: A novel refractive index (RI) and temperature all-fiber ring laser sensor based on single-mode-tapered claddingless-single-mode (STCS) fiber structure is proposed and experimentally demonstrated. The STCS fiber structure acts as the sensing head and the filter of laser simultaneously. Thanks to the laser sensing system, high optical signal-to-noise ratio ( \(\sim 40\) dB) and narrow 3-dB bandwidth (<0.12 nm) are achieved. For RI measurement, the average sensitivity reaches 163.80 nm/RIU in the RI range of 1.333–1.399. While for temperature measurement, a sensitivity of 10.8 pm/°C is achieved with the temperature ranging from 8 °C to 80 °C. The proposed system is simple and easy to construct, meanwhile, it shows the merits of high resolution, high signal-to-noise ratio and easier to monitor.
40 citations
TL;DR: In this paper, a multimode interference refractive index (RI) sensor based on the coreless fiber was numerically and experimentally demonstrated, and the relative error was merely 1% which occupied preferable sensing performance and practicability.
Abstract: A multimode interference refractive index (RI) sensor based on the coreless fiber was numerically and experimentally demonstrated Two identical single mode fibers (SMF) are spliced at both ends of a section of the coreless fiber which can be considered as the equivalent weakly guiding multimode fiber (MMF) with a step-index profile when the surrounding refractive index (SRI) is lower than that of the coreless fiber Thus, it becomes the conventional single-mode multimode single-mode (SMS) fiber structure but with a larger core size The output spectra will shift along with the changes in the SRI owing to the direct exposure of the coreless fiber The output spectra under different SRIs were numerically studied, as well as the sensitivities with different lengths and diameters of the coreless fiber The predication and calculation showed the good agreement with the experimental results The proposed RI sensor proved to be feasible by verification experiments, and the relative error was merely 01% which occupied preferable sensing performance and practicability
34 citations
TL;DR: In this paper, the authors proposed a compact all-fiber sensor for simultaneous measurement of temperature and refractive index (RI), which is based on a no-core fiber and fiber Bragg grating (FBG).
Abstract: We propose and demonstrate a compact all-fiber sensor for simultaneous measurement of temperature and refractive index (RI), which is based on a no-core fiber (NCF) and fiber Bragg grating (FBG). Two segments of NCF used as beam splitter and combiner are embedded on the two ends of an FBG, which constitute a Mach–Zehnder (MZ) interferometer susceptible to the temperature and an ambient RI. With the change of RI and temperature, MZ interference and Bragg reflection result in the variation of transmission spectrum. The experimental results show that the sensitivity of RI is −109.573 nm/RI in the range from 1.333 to 1.398, and the sensitivity of temperature ranging from 10 °C to 70 °C is 0.014 nm/°C, respectively. The feasibility of simultaneous measurement of an external RI and the temperature with this configuration has been demonstrated experimentally.
33 citations
TL;DR: A novel all-fiber sensing configuration for simultaneous measurements of temperature and strain based on the up-taper Mach-Zehnder interferometer (MZI) with an in-line embedded fiber Bragg grating (FBG) is proposed and experimentally demonstrated.
Abstract: A novel all-fiber sensing configuration for simultaneous measurements of temperature and strain based on the up-taper Mach-Zehnder interferometer (MZI) with an in-line embedded fiber Bragg grating (FBG) is proposed and experimentally demonstrated This configuration consists of two up-tapers fabricated by an excessive fusion splicing method and a short segment of inscribed FBG Due to the different responses of the up-taper MZI and the FBG to the uniform variation of temperature and strain, the simultaneous measurement for these two variables could be achieved by real-time monitoring the transmission spectrum For 001 nm wavelength resolution, a resolution of 0311°C in temperature can be achieved, and the average strain resolution is 1007 μe
29 citations
TL;DR: In this paper, a tunable erbium-doped all-fiber laser was demonstrated, which is based on a fiber filter using the refractive index characteristics of multimode interference effects.
Abstract: A tunable erbium-doped all-fiber laser has been demonstrated. This tunable laser is based on a tunable fiber filter using the refractive index characteristics of multimode interference effects. A thinner no-core fiber with a diameter of 104 μm is used to fabricate the tunable fiber filter. The joint point of the thinner no-core fiber with SMF is a taper, which improves its sensitivity for refractive index changes. The filter exhibits a very sensitive response to the change of the environmental refractive index, which is about 1000 nm/RIU in the RI range from 1.418 to 1.427. The tunable fiber laser based on the filter achieved a tunability of 32 nm, with the wavelength tuned from 1532 nm to 1564 nm covering the full C-band. The 3 dB bandwidth of the tunable laser is less than 0.02 nm with the signal-to-noise ratio of about 40 dB.
28 citations
TL;DR: In this article, the authors investigate numerically the synchronization of two multimode semiconductor ring laser (SRLs) and demonstrate its potential in chaos-based communication and evaluate the extent of the SRL's chaos regime under external optical feedback in terms of bifurcation diagram and the optimal feedback strength range for reliable chaotic communication.
Abstract: We investigate numerically the synchronization of two multimode semiconductor ring lasers (SRLs) and demonstrate its potential in chaos-based communication. The extent of the SRL's chaos regime under external optical feedback is evaluated in terms of bifurcation diagram and the optimal feedback strength range for reliable chaotic communication is discussed as well. Under proper conditions, the receiver SRL can be satisfactorily synchronized with the transmitter SRL due to the injection-locking effect. The message encoding and decoding using chaos shift keying technique have been analyzed from the point of view of the total lasing output. The possibility of recovering the message using unidirectional output (clockwise output or counterclockwise output) is also examined and compared with that of the total output. The tolerance of the proposed scheme to the SRL's fabrication limitation and parameter mismatch are studied. In view of these results, chaos-based synchronization and communication over fiber optical link, with or without the amplified spontaneous emission noise induced by amplification, are demonstrated. We also check the negative influence of fiber nonlinearity on the system transmission performance.
TL;DR: In this paper, a polarization-maintaining chirped fiber Bragg grating (PM-CFBG) is presented for temperature-independent and strain-independent twist measurement.
Abstract: In this letter, we present a structured polarization-maintaining chirped fiber Bragg grating (PM-CFBG) for temperature-independent and strain-independent twist measurement. The structured PM-CFBG, which has two transmission peaks, is created by tapering directly on the PM-CFBG. The grating transmissivity of structured PM-CFBG changes linearly with twist while it is insensitive to strain and temperature. The wavelength interval changes proportionally to the temperature, but remains the same as the strain increases. This novel sensor can be used to measure temperature, strain, and twist simultaneously.
TL;DR: Both the numerical and analytical results have shown that the graphene- coated tapered nanowire probe could achieve an order of magnitude larger field enhancement than the metal-coated probes.
Abstract: We propose in this paper a graphene-coated tapered nanowire probe providing strong field enhancement in the infrared regimes. The analytical field distributions and characteristic equation of the supported surface plasmons mode are derived. Based on the adiabatic approximation, analytic methods are adopted in the investigation of field enhancement along the tapered region and show well consistence with the rigorous numerical simulations. Both the numerical and analytical results have shown that the graphene-coated nanowire probe could achieve an order of magnitude larger field enhancement than the metal-coated probes. The proposed probe may have promising applications for single molecule detection, measurement and nano-manipulation techniques.
TL;DR: A simple, compact, and highly sensitive optical fiber curvature sensor that consists of dual no-core fibers for coupling energy from the lead-in single-mode fiber, and recoupling the energy into thelead-out SMF.
Abstract: In this paper, we present a simple, compact, and highly sensitive optical fiber curvature sensor It consists of dual no-core fibers for coupling energy from the lead-in single-mode fiber (SMF), and recoupling the energy into the lead-out SMF The sensing section is constituted by multicladding fiber with a length of 5 cm In the experiment, the spectrum shows a blueshift, and the energy corresponding to the resonant wavelength shows a cosine series with a bending of the sensing segment The curvature sensitivity around the wavelength of 1550 nm shows −3902 nm/m−1 within the curvature range from 03 to 214 m−1 The temperature sensitivity is 782 pm/°C in the temperature range of 10°C–60°C It implies the possibility of temperature measurement
TL;DR: In this article, a singlemode-coreless-singlemode (SCS) fiber structure-based fiber ring cavity laser for strain and temperature measurement is proposed, where the fiber structure not only acts as sensing head of the sensor but also acts as the band-pass filter of the ring laser.
Abstract: This paper experimentally demonstrated a singlemode–coreless–singlemode (SCS) fiber structure-based fiber ring cavity laser for strain and temperature measurement. The basis of the sensing system is the multimodal interference occurs in coreless fiber, and the transmission spectrum is sensitive to the ambient perturbation. In this sensing system, the SCS fiber structure not only acts as the sensing head of the sensor but also the band-pass filter of the ring laser. Blue shift with strain sensitivity of $$\sim$$
−2 pm/μe ranging from 0 to 730 μe and red shift with temperature sensitivity of $$\sim$$
11 pm/°C ranging from 5 to 75 °C have been achieved. Experimental results also show the proposal has great potential in using long-distance operation. The fiber ring laser sensing system has a optical signal to noise ratio (OSNR) more than 50 and 3 dB bandwidth less than 0.05 nm. The result shows that the coreless fiber has no improvement of the temperature and axial strain sensitivity. However, compared to the common singlemode–multimode–singlemode fiber structure sensors, the laser sensing system has the additional advantages of high OSNR, high intensity and narrow 3 dB bandwidth, and thus improves the accuracy.
TL;DR: In this article, a switchable single-polarization dual-wavelength single-longitudinal mode (SLM) erbium-doped fiber (EDF) ring laser is proposed and demonstrated.
Abstract: A switchable single-polarization dual-wavelength single-longitudinal mode (SLM) erbium-doped fiber (EDF) ring laser is proposed and demonstrated. For the first time, the structured polarization-maintaining chirped fiber Bragg grating (PM-CFBG) filter, which has ultranarrow transmission band is created by tapering directly on the PM-CFBG. Then, the stable SLM operation of the fiber laser is guaranteed by the structured PM-CFBG filter and 20-cm unpumped EDF acting as a saturable absorber. Meanwhile, the stable dual-wavelength fiber laser with a wavelength spacing of \(\sim 0.41\) nm and stable single polarization state is experimentally realized. The measured linewidth of the fiber laser for each wavelength is \( kHz with a 20-dB linewidth.
TL;DR: In this article, a widely tunable dual-wavelength erbium-doped fiber laser based on a cascaded Sagnac loop interferometer incorporating a multimode interference filter is proposed and experimentally demonstrated.
Abstract: A widely tunable dual-wavelength erbium-doped fiber laser based on a cascaded Sagnac loop interferometer incorporating a multimode interference filter is proposed and experimentally demonstrated in this paper. The mode selection is implemented by using the cascaded Sagnac loop interferometer with two segments of polarization maintaining fibers, and the wavelength tuning was achieved by using the refractive index characteristic of multimode interference effects. The tunable dual-wavelength fiber laser has a wavelength tuning of about 40 nm with a signal-to-noise ratio of more than 50 dB.
TL;DR: Both the high order mode (HOM) suppression and bending resistance of the two-layer low-index trench fiber with parabolic-profile core are better than that of Multi-Trench Fiber (MTF).
Abstract: A novel design, two-layer low-index trench fiber with parabolic-profile core, is proposed and investigated numerically in this paper. Based on scalar FD-BPM algorithm, the excellent performance over other types of structures and great potential in mode area enlargement are demonstrated. The effective mode area of our design (D = 100μm) is approximately 890 μm2. Both the high order mode (HOM) suppression and bending resistance of our design are better than that of Multi-Trench Fiber (MTF). The mode loss ratio and effective mode area are independent on the bending radius. Due to the circular symmetry of our proposed configuration design, the bending property is not varied with the changing of bending directions.
TL;DR: In this paper, a multilayer-core intrinsically single-mode large-mode-area fiber is proposed, which is composed of alternating low- and high-refractive index rings.
TL;DR: Theoretical investigation shows that the waveguide has the ability to turn on or off the mid-infrared light from 5400 nm to 5800 nm and adjusting the voltages on graphene layers can alter the bandwidth of trapped light.
Abstract: We present a detailed study on trapping and releasing of light in a graded graphene-silica metamaterial waveguide. By applying proper gate voltages onto the graphene layers, the metamaterial with graded-permittivity has the ability to trap the light due to the vanishing of normalized optical power flow between forward and backward modes. Based on the effective medium theory, the distributions of modes and the transmission characteristics of normalized power flows are investigated. Theoretical investigation shows that the waveguide has the ability to turn on or off the mid-infrared light from 5400 nm to 5800 nm. Moreover, adjusting the voltages on graphene layers can alter the bandwidth of trapped light. The graded metamaterial waveguide can be the candidate for multi-wavelength absorber based on the light trapping effect.
TL;DR: In this paper, an elliptical multilayer-core-fiber (EMCF) with linearity for wide-band dual-mode operation was proposed, in which only the HE 11 and HE 21 modes could be propagated, and the characteristics of the EMCF, including modal properties, the operating wavelength, the transmission loss, the effective area and the bending loss, were systematically investigated.
Abstract: . Anellipticalmultilayer-corefiber(EMCF)withlownonlinearityforwide-banddual-modeoperationwasproposed. The EMCF, in which only the HE 11 and HE 21 modes could be propagated, supported a distinct dual-mode operation. The characteristics of the EMCF, including modal properties, the operating wavelength, thetransmission loss, the effective area, and the bending loss, were systematically investigated. For EMCFs, alarge modal diameter (33.48 μm) was achieved to reduce the fiber nonlinear penalty; meanwhile, the bendingloss could be kept in a lower level. In addition, the single-polarization property in EMCFs could be realized bycombining stress applying elements. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10.1117/1.OE.53.10.105104] Keywords: dual-mode fiber; large mode area; bending loss; single polarization; elliptical multilayer-core fiber.Paper 141171 received Jul. 22, 2014; revised manuscript received Sep. 26, 2014; accepted for publication Sep. 29, 2014; publishedonline Oct. 30, 2014.
TL;DR: In this paper, a cost-effective ultra-dense wavelength-division-multiplexed passive optical network (UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 1.5 GHz is proposed and demonstrated.
Abstract: A cost-effective ultra-dense wavelength-division-multiplexed passive optical network (UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz is proposed and demonstrated. The distributed feedback (DFB) lasers modulated in 4-level pulse amplitude modulation (4-PAM) format are used for downstream links, and the reflective semiconductor optical amplifiers (RSOAs) together with an optical frequency comb modulated in quadrature phase shift keying (QPSK) format are used for upstream links. We can achieve the error-free transmission of the upstream signals with speed of 12.5 Gbit/s even after 20 km single-mode fiber (SMF). The power penalty obtained by using the frequency comb generator instead of a tunable laser is around 0.5 dB. By using 11 DFB lasers and a set of intensity and phase modulators, it is possible to provide the seed light for 297 optical network units (ONUs) within the C-band.
TL;DR: Experimental results showed that the proposed analytic method had higher accuracy in the calculation of cut-off wavelength for BIFs that had a large proportion of depressed inner-cladding layer, which significantly expanded the range of accurately predicting the cut-offs wavelength.
Abstract: An analytic method for solving the cut-off wavelength of single groove-assisted bend-insensitive fiber (BIF) was proposed. Combined with the concepts of frustrated total reflection and numerical aperture, the cut-off wavelength formula for the BIF was deduced. Experimental results showed that, compared to the traditional analytic and numeric methods, this method had higher accuracy in the calculation of cut-off wavelength for BIFs that had a large proportion of depressed inner-cladding layer, which significantly expanded the range of accurately predicting the cut-off wavelength.
TL;DR: In this article, the authors investigated the effect of the backscattering coefficient on the relative intensity noise (RIN) spectrum in typical operation regimes of a semiconductor ring laser (SRL).
Abstract: Based on the frequency-domain multimode theoretical model, detailed investigations on the noise characteristic of the semiconductor ring laser (SRL) are first performed in this paper. The comprehensive nonlinear terms related to the third order nonlinear susceptibility χ3 are included in this model; the Langevin noise sources for electric field and carrier density fluctuations are also taken into account. As the injection current increases, the SRL may present several operation regimes. Remarkable and unusual low frequency noise enhancement in the form of a broad low frequency tail extending all the way to the relaxation oscillation peak is observed in any of the operation regimes of SRLs. The influences of the backscattering coefficient on the relative intensity noise (RIN) spectrum in typical operation regimes are investigated in detail.
11 Nov 2014
TL;DR: In this paper, a universal scaling law to describe dispersion relation of plasmon modes in graphene-coated nanowire (GNW) is presented, which could be applied to obtain the dispersion relations of GNW with any radius without further extensive calculation.
Abstract: A universal scaling law to describe dispersion relation of plasmon modes in graphene-coated nanowire (GNW) is presented, which could be applied to obtain the dispersion relation of GNW with any radius without further extensive calculation.