Jiangping Xie

Amplified spontaneous emission of an Nd3+-doped poly(methyl methacrylate) optical fiber at ambient temperature

Polymer optical fibers have received much attention in recent years as they can replace silica glass fibers in local area nets in the future. A neodymium ion (Nd3+)-doped poly(methyl methacrylate) (PMMA) fiber has been made from Nd3+ containing PMMA as a core and silica resin as claddings. Fluorescence of the fiber results from the transition of 4G5/2 to 4I9/2 in a three energy level system. Amplified spontaneous emission (ASE) at 575 nm has also been observed and the critical power at a pump wavelength of 514.5 nm for the onset of ASE has been found to be 85 mW.

Novel 3D multilayered waveguide memory

In this paper, we propose a novel method of three dimensional optical storage by the use of multilayered waveguide memory (MWM). The MWM structure is described and its work principle is introduced. Some properties and merits of MWM are also discussed in comparison with other 3D optical data storage methods.

Birefringent gratings induced by polarized laser in azobenzene-doped poly(methyl methecrylate) optical fibers

Birefringence gratings induced by 532nm polarized laser in an azobenzene doped polymethyl methacrylate (PMMA) fiber and perform block were investigated. Significant photo-induced birefringence has been observed from the fiber. The maximum induced index change is about 3.1x10+MIN5) from this material. The induced birefringence was attributed to the nonlinear absorption at 532nm wavelength. It is found there is the threshold intensity of 0.29mW/cm2. The birefringence decayed little by little when laser turned off, a certain amount of saturation was remained. The dynamics process of the birefringence was studied. This birefringent grating may apply in the polarization dispersion compensation of the fiber communication.

Two-photon bit data storage in azobenzene polymer liquid crystal using low-power cw laser

In this paper, two-photon bit data storage in azobenzene polymer liquid crystal (PLC) film using low-power continuous wave (CW) laser beam at 532 nm is proposed and demonstrated for the first time, the exposure threshold of the material is below 4 X 106 mw/cm2, and a bit data storage pattern is recorded by two-photon absorption (TPA). The data is easily erasable and rewritable by the light of the same wavelength as the recording light.

Wavelength-tunable single-frequency Er:Yb codoped DBR fiber laser

A diode-pumped, compact, wavelength tunable, single frequency Er3+:Yb3+ codoped DBR fiber laser is reported. An output power of 2.4mW for 75mW of 980nm diode pump power and a slope efficiency of 6% at 1557.05nm were obtained. Linewidth of the laser was estimated at 1557.05nm to be less than 1MHz. Also, the laser can be tuned to wavelengths between 1557nm to 1561nm and operates single mode throughout this range.

The write strategy investigation of multi-level optical storage in azobenzene liquid crystal polymer film

With the increasing demand of optical storage capacity, multi-level (ML) optical storage based on multi-level-amplitude modulation is receiving more and more attention, for it transmits more information ove a fixed bandwidth channel by using the available SNR more efficiently. We proposed an ML optical storage technology in azo LCP film based on polarization angle division. In this paper, the write strategy is developed by a ML write-compensation system that corrects for non-linearities of the data signal. The dynamic transmittance range is extended with the full monotonic range of angle and the varaition of each amplitude level relative to our dynamic range is improved. The experiments of imroved linear and nonlinear 16-level storage in azo LCP are demonstrated. The effects of thickness non-uniformity on linear and nonlinear 16-level storage are discussed.

Numerical analysis of micro-aperture laser for near field optical data storage

The very small aperture laser (VSAL) is an important light source used in the near-field optical storage system. It is necessary for studying the near-field property of VSALs output light. The optical characters and the intensity distribution in the near-field of the output region of the VSAL have been numerical simulated using two dimension nonlinear FDTD (2D-NL-FDTD) method and the Fox-Li method. Through analyzing the results from the viewpoint of the Optics, the possible application in the near-field optical recording have been discussed, and some curves indicating the near-field optical characters of the output light have been presented.

Numerical simulation of electromagnetic propagation in high-data- density near-field optical recording

The optical characters and light wave propagation of various fiber probes, solid immersion lens (SIL) system and Super-RENS for near-field optical recording are numerically simulated using 3D finite-difference time-domain (3D-FDTD) method in this paper. The aperture metal-coated probe have a near field spot size smaller than the bare-glass fiber probe, which means higher data density in near-field optical recording. The entirely metal coat probe is pointed out to have an extremely small near-field spot size about 10 nm, but the output electromagnetic wave propagation decrease to nearly zero within a few nanometers. The propagating and evanescent wave in different solid immersion lens (SIL) system is numerically simulated. The spot sizes are different because of different polarization. With the TbFe substrate, spot size will remain constant as observation distance z increased. But the propagating, evanescent and total energy decay more rapidly than the SIL system without TbFe substrate.

Self-injection-locking single frequency Yb-doped fiber ring laser

The self-injection locking single frequency Yb-doped fiber ring laser is reported. The system shows compact, stable and tunable. In the primary experiment, the Self-injection locking single frequency fiber ring laser with wavelength 1.05325)mum, power exceeding 3.5mW,line-width less than 36 MHz was manufactured. The laser shows stability, low threshold and high power. No mode-hopping was observed within 2 hours. The single polarization output can be obtained when use single polarization fiber.

3D profile reconstruction using optical fiber Fizeau interferometer

In this article, a new method is introduced to reconstruct 3D profile from the 2D interferogram of Fizeau Interferometer. By using matrix optics, the interferometric mechanism is analyzed. On this bases, the relationship between the interference pattern and 3D profile is built up by fringe tracing of two interferograms of the object to be tested at two places with a certain separation. Depending on the relationship, the data profile are figured out and the 3D profile is obtained with the aid of computer.