Li Yan-Feng

Adaptive split-step Fourier method for simulating ultrashort laser pulse propagation in photonic crystal fibres

In this paper, the generalized nonlinear Schrodinger equation (GNLSE) is solved by an adaptive split-step Fourier method (ASSFM). It is found that ASSFM must be used to solve GNLSE to ensure precision when the soliton self-frequency shift is remarkable and the photonic crystal fibre (PCF) parameters vary with the frequency considerably. The precision of numerical simulation by using ASSFM is higher than that by using split-step Fourier method in the process of laser pulse propagation in PCFs due to the fact that the variation of fibre parameters with the peak frequency in the pulse spectrum can be taken into account fully.

Theoretical Study on a Cluster-Seven-Core Photonic Crystal Fiber with High Nonlinearity and High-Power Endurance

We present a novel cluster-seven-core photonic crystal fiber which possesses high nonlinearity and supports the high-power pumping. Its nonlinearity coefficient and effective mode area are calculated by the full vector multipole method. Compared with the single core PCF, the cluster-seven-core photonic crystal fiber can support high-power beam transmitting in the core, and simultaneously has high nonlinearity. This kind of photonic crystal fiber can be applied to the photoelectron-device field.

Enhanced nonlinear effects in photonic crystal fibers

Photonic crystal fibers are a new class of single-material optical fibers with wavelength-scale air holes running down the entire fiber length. Photonic crystal fibers were first developed in 1996 and have subsequently been the focus of increasing scientific and technological interest in the field of fiber optics. The manufacturing, principles, basic properties, and some applications of photonic crystal fibers are briefly described in this paper. A review of our recent work on the nonlinear effects in photonic crystal fibers is presented, and special emphasis is placed on such effects as supercontinuum generation, frequency conversion, and solitons observed when femtosecond light pulses propagate in these fibers.

The method of multi-view adaptive display on optical-plate stereo mobile phone

As the maximum of viewpoint in each optical-plate unit attached with the mobile phone is fixed, when the bandwidth of wireless network is insufficient, the data of videos with the maximum viewpoints will not be transferred perfectly. The multi-view adaptive display method on optical-plate stereo mobile phone can increase or decrease the multi-view stereo videos according to the network bandwidth, transfer the data of stereo videos as many as possible and re-arrangement pixels of received stereo videos on the stereo mobile phone. Experimental results indicate that the proposed method can fully utilize the network bandwidth and maintain the display stereoscopy and clarity of multi-view stereo videos, which is very important to real-time transfer and display multi-view stereo videos.

Operation of Kerr-lens mode-locked Ti：sapphire laser in the non-soliton regime

A Kerr-lens mode-locked Ti:sapphire laser operating in a non-soliton regime is demonstrated. Dispersive wave generation is observed as a result of third order dispersion in the vicinity of zero dispersion. The characteristics of the Ti:sapphire laser operating in a positive dispersion regime are presented, where the oscillator directly generates pulses with duration continuously tunable from 0.37 ps to 2.11 ps, and 36 fs pulses are achieved after extracavity compression. The oscillation is numerically simulated with an extended nonlinear Schrodinger equation, and the simulation results are in good agreement with the experimental results.

Multi-Slit Diffraction of Evanescent Electromagnetic Waves

The well-known Fraunhofer multi-slit diffraction is described as the multi-slit interference modulated by the single-slit diffraction, namely the multiplication between the single-slit diffraction factor and the multi-slit interference factor. By considering the simplified argument we show that the multi-slit diffraction of evanescent waves which are in the near-field region also has the interference and diffraction effects, and that this two-fold effect can be expressed as the convolution of the diffraction factor and the interference factor. Our conclusion could be helpful to understand the contribution of evanescent waves to the optical responses of sub-wavelength structures such as slits and grooves.