Xinben Zhang

A hollow beam supercontinuum generation by the supermode superposition in a GeO 2 doped triangular-core photonic crystal fiber

A GeO2 doped triangular-core photonic-crystal fiber (PCF) is designed and fabricated to allow the generation of a hollow beam through a nonlinear-optical transformation by femtosecond pulses at 1040 nm from a high power Yb-doped PCF laser oscillator. The hollow beam supercontinuum is obtained at far field by adjusting incident light polarization to excite the high order supermode, behaving as a mode convertor. The supercontinuum ranging from 540 to 1540 nm is achieved with an average power of 1.04 W.

Blue light generation in photonic crystal f ibers with 1-\mm m femtosecond laser pulses

Using 300-fs 1039-nm Yb-doped fiber laser, we experimentally demonstrate blue light generation in a high-\Delta and high nonlinear photonic crystal fiber (PCF). The zero dispersion wavelength of PCF is 793 nm, detuning 245.8 nm from the pump wavelength. PCF allows a frequency conversion exceeding the octave of pump wavelength. The visible component of the measured output spectrum occurs in the fundamental mode and spans from 391.3 to 492.3 nm. The peak wavelength of 441.8 nm has a frequency detuning of 390 THz from the pump wavelength of 1039 nm.

Fabrication and characteristic of a simplified hollow-core microstructured fiber

A simplified hollow-core microstructured fiber was fabricated and investigated. The diameter of the core is about 31 μm, and the thickness of the bridges t is about 280 nm. Three broad band transmission windows with relative low loss were measured in IR domain with the large bandwidth of ~600 nm. A Gaussian-shaped beam profile with visible pattern guided by the large core was observed in far field. The curvature behavior was also studied. This large core broad band transmission fiber offers a good medium for applications in high energy delivery, novel gas-cell based laser and sensing devices.

21 Port self wavelength switching of 40 Gb/s spectral-amplitude-encoded DPSK signals

Ultrafast self-switching of spectral-amplitude-encoded 40 Gb/s DPSK signals is demonstrated for the first time. Switching between 21 ports with 15 nm maximum bin separation is achieved using a single correlator based on HNLF and an AWG.

Proposal for a novel and simple WDM NRZ-DPSK system

We propose a novel and simple non-return-to-zero differential phase shift keying (NRZ-DPSK) wavelength division multiplexing (WDM) system which can simultaneously demultiplex and demodulate multiple wavelengths. The phaseto- intensity demodulation principle is based on detuned filtering, which is achieved by using a single commercial array waveguide grating (AWG) in our scheme. By properly choosing appropriate AWG channels at the transmitter, the AWG at the receiver can act as both the de-multiplexer and the demodulator of the DPSK signals. Simulations at 10, 20 and 40Gb/s show good flexibility and performance for the proposed system.