Nanosecond Pulse Generation Using the Stimulated Brillouin Scattering Effect in a Photonic Crystal Fiber

A nanosecond pulsed laser is demonstrated using the stimulated Brillouin scattering(SBS)effect in a nonlinear photonic crystal fiber(PCF).The Brillouin fiber laser(BFL)uses a 50-m-long PCF in a simple ring cavity to generate a self-starting pulse as the Brillouin power reaches 16.5 dBm based on the relaxation oscillation technique.The BFL generates a pulse train with repetition rates of 2.7 MHz and 5.4 MHz depending on the BP power.The pulse width of the laser is obtained to be 190 ns at the BP power of 16.5 dBm and is maintained at around 72 ns as the pump power is set within 17.7 dBm and 18.5 dBm.The maximum pulse energy of 20 nJ is obtained at BP power of 17.4 dBm.This SBS based pulse laser is fairly stable at room temperature.

Self-Starting Harmonic Mode-Locked Thulium-Doped Fiber Laser with Carbon Nanotubes Saturable Absorber

We report a ring cavity passively harmonic mode-locked thulium-doped fiber laser(TDFL)using a newly devel-oped single-wall carbon nanotube-based saturable absorber.The TDFL generates the 25 th harmonic mode-locked stretched pulse train with a high repetition rate of 213MHz and a pulse duration of 710fs.The laser operates at 1901.6nm with an average power of 1.89mW,which corresponds to the pulse energy of 0.008nJ,at 1552nm pump power of 719mW.The peak-to-background ratio is measured to be 60dB,which indicates the stability of the laser.

Q-switched Er-doped fiber laser with low pumping threshold using graphene saturable absorber

We propose a Q-switched Er-doped fiber laser （EDFL） with a threshold pumping power as low as 7.4 mW, and demonstrate using graphene polyvinyl alcohol （PVA） thin film as a passive saturable absorber （SA）. The SA is fabricated from graphene flakes, which is synthesized by electrochemical exfoliation of graphite at room temperature in 1% sodium dodecyl sulfate aqueous solution. The flakes are mixed with PVA solution to produce a thin film, which is then sandwiched between two ferrules to form a SA and integrated in the EDFL ring cavity to generate a stable Q-switched pulse train. The pulse train operates at 1560 nm with a threshold pump power of 7.4 roW. At maximum 1480 nm pump power of 33.0 roW, the EDFL generates an optical pulse train with a repetition rate of 27.0 kHz and pulse width of 3.56/as. The maximum pulse energy of 39.4 nJ is obtained at a pump power of 14.9 roW. This laser can be used as a simple and low-cost light source for metrology, environmental sensing, and biomedical diagnostics.

Ionic Conductivity and Dielectric Properties of the PAN-Ion Conducting Polymers

1 Results In this work, the ion conducting films of polyacrylonitrile (PAN) containing lithium triflate (LiCF3SO3) and sodium triflate (NaCF3SO3) were prepared by the solution casting technique. The ionic conductivity measurements were carried out using impedance spectroscopy. The room temperature conductivity for pure polyacrylonitrile film is 1.51×10-11 S·cm-1. The room temperature conductivity for the highest conducting film in the PAN-LiCF3SO3 and PAN-NaCF3SO3 systems is 1.51×10-5 and 7.99×10-6 S·...

Photonic crystal ber-based multi-wavelength Brillouin ber laser with dual-pass ampli cation con guration

A simple technique for achieving a stable, room temperature and multi-wavelength lasing with narrow linewidth is demonstrated using Brillouin ber laser （BFL） with a 100-m-long photonic crystal ber （PCF） in conjunction with a dual-pass configuration. A broadband ber Bragg grating （FBG） operating in the C-band region is incorporated at the end side of the setup to allow a dual-pass operation. The proposed BFL can operate at any wavelength depending on the Brillouin pump wavelength and the FBG＇s reflection region used. With a Brillouin pump （BP） of 15.7 dBm, approximately 7 Stokes and 4 anti-Stokes lines are obtained with a line spacing of 0.08 nm.