Femtosecond optical pulses have applications in optical communication, astronomical frequency combs, and laser spectroscopy. Here, a hybrid mode-locked erbium-doped fiber (EDF) laser with topological insulator (TI) is proposed, for the first time to our best knowledge. The pulsed laser deposition (PLD) method is employed to fabricate the fiber-taper TI saturable absorber (TISA). By virtue of the fiber-taper TISA, the hybrid EDF laser is passively mode-locked using the nonlinear polarization evolution (NPE), and emits 70 fs pulses at 1542 nm, whose 3 dB spectral width is 63 nm with a repetition rate and transfer efficiency of 95.4 MHz and 14.12%, respectively. Our experiments indicate that the proposed hybrid mode-locked EDF lasers have better performance to achieve shorter pulses with higher power and lower mode-locking threshold in the future.

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Extensive calculations on isoscaling behavior with the sequential-decay model GEMINI are performed for the mediate-heavy nuclei in the mass range A = 60-120 at excitation energies up to 3 MeV per nucleon. The comparison between the products after the first-step decay and the ones after entire-steps decay demonstrates that there exists strong sequential decay effect on the final isoscaling parameters and the apparent temperature. Results show that the apparent symmetry energy coefficient γapp does not reflect the initial symmetry energy coefficient Csym embedded in the mass calculation in the present GEMINI model.

Two kinds of novel plasmonic high-sensitivity of refractive index(RI) sensors based on analyte-filled photonic crystal fiber (AF-PCF) are proposed in this paper. The metallic gold and silver is used as the surface plasmon resonance (SPR) activity metal. A full-vector finite element method (FEM) is applied to analyze and investigate the sensing and coupling characteristics of this designed AF-PCF with the gold or silver layer. Phase matching between 2nd surface plasmon polariton (SPP) and fundamental modes can be met at different wavelengths as the analyte of RI is increased from 1.40 to 1.42. The phase matching wavelength of the designed AF-PCF with the gold layer is shifted to the longer wavelength direction compared to that with the silver layer, and the resonance strength is much stronger. The average sensitivities of 7040 nm/RIU and 7017 nm/RIU in the sensing arrange from 1.40 to 1.42 with high linearity are achieved for the designed sensors with the gold and silver layers, respectively, which are almost the same. While the figure of merit (FOM) with silver layer is much better than that with the gold layer.Index Terms: Photonic crystal fiber, Surface plasmon resonance. Refractive index sensor 1943-0655 (c)

A collection of materials and device architectures are introduced for thin, stretchable arrays of ion sensors that mount on open cellular substrates to facilitate solution exchange for use in biointegrated electronics. The results include integration strategies and studies of fundamental characteristics in chemical sensing and mechanical response. The latter involves experimental measurements and theoretical simulations that establish important considerations in the design of low modulus, stretchable properties in cellular substrates, and in the realization of advanced capabilities in spatiotemporal mapping of chemicals' gradients. As the chemical composition of extracellular fluids contains valuable information related to biological function, the concepts introduced here have potential utility across a range of skin- and internal-organ-integrated electronics where soft mechanics, fluidic permeability, and advanced chemical sensing capabilities are key requirements.

Abstract. The isospin effect and isoscaling behavior in projectile fragmentation have been systematically investigated by a modified statistical abrasion-ablation (SAA) model. The normalized peak differences and reduced isoscaling parameters are found to decrease with (Z proj − Z)/Z proj or the excitation energy per nucleon and have no significant dependence on the size of reaction systems. Assuming a Fermi-gas behavior, the excitation energy dependence of the symmetry energy coefficients are tentatively extracted from α and β which looks consistent with the experimental data. It is pointed out that the reduced isoscaling parameters can be used as an observable to study excitation extent of system and asymmetric nuclear equation of state in heavy ion collisions.

The18 Ne(α,p) 21 Na reaction is thought to be one of the key breakout reactions from the hot CNO cycles to the rp-process in type I x-ray bursts. In this work, the resonant properties of the compound nucleus 22 Mg have been investigated by measuring the resonant elastic scattering of 21 Na+p. An 89 MeV 21 Na radioactive beam delivered from the CNS Radioactive Ion Beam Separator bombarded an 8.8 mg/cm 2 thick polyethylene (CH2)n target. The 21 Na beam intensity was about 2×10 5 pps, with a purity of about 70% on target. The recoiled protons were measured at the center-of-mass scattering angles of θc.m.≈175.2• , 152.2 • , and 150.5• by three sets of ∆E-E telescopes, respectively. The excitation function was obtained with the thick-target method over energies Ex( 22 Mg)=5.5-9.2 MeV. In total, 23 states above the proton-threshold in 22 Mg were observed, and their resonant parameters were determined via an R-matrix analysis of the excitation functions. We have made several new J π assignments and confirmed some tentative assignments made in previous work. The thermonuclear 18 Ne(α,p) 21 Na rate has been recalculated based on our recommended spin-parity assignments. The astrophysical impact of our new rate has been investigated through one-zone postprocessing x-ray burst calculations. We find that the 18 Ne(α,p) 21 Na rate significantly affects the peak nuclear energy generation rate, reaction fluxes, as well as the onset temperature of this breakout reaction in these astrophysical phenomena.

The longitudinal momentum distribution (P // ) of fragments after one-proton removal from 23 Al and reaction cross sections (σR) for 23,24 Al on carbon target at 74A MeV have been measured. The 23,24 Al ions were produced through projectile fragmentation of 135A MeV 28 Si primary beam using RIPS fragment separator at RIKEN. P // is measured by a direct time-of-flight (TOF) technique, while σR is determined using a transmission method. An enhancement in σR is observed for 23 Al compared with 24 Al. The P // for 22 Mg fragments from 23 Al breakup has been obtained for the first time. FWHM of the distributions has been determined to be 232±28 MeV/c. The experimental data are discussed by using Few-Body Glauber model. Analysis of P // demonstrates a dominant d-wave configuration for the valence proton in ground state of 23 Al, indicating that 23 Al is not a proton halo nucleus.