Biomedical subjects

Shizhong Xie

Publications and source records attributed to Shizhong Xie.

6 recordsLinked to original sources

PubMed2006

Broadband dispersion-compensating photonic crystal fiber.

We present a modified dual-core photonic crystal fiber, based on pure silica, with special grapefruit holes in the inner cladding. The fiber has large, broadband negative dispersion, and the dispersion value varies linearly from -380 t o-420 ps/(nm km) in the C band. To decrease the fabrication difficulty, large air holes are adopted. Furthermore, the chromatic dispersion of the fiber is not sensitive to the structure parameters. So the proposed fiber structure can greatly facilitate fiber drawing and can be used for broadband dispersion compensation.

Journal Article↗

PubMed2006

High-performance, high-chip-count optical code division multiple access encoders-decoders based on a reconstruction equivalent-chirp technique.

Fiber Bragg grating-based, 511 chip, 500 Gchip/s encoders-decoders are experimentally demonstrated by the reconstruction equivalent-chirp (REC) method. Encoding-decoding efficiency close to the theoretical value is achieved. Without any real phase shifts, the encoders-decoders are fabricated by use of the traditional setup. Highly precise phase control requires only submicrometer precision. The encoding-decoding performance can be further improved by REC-based correction.

Journal Article↗

PubMed2006

Optical labeling scheme using polarization shift keying/vestigial sideband carrier-suppressed return-to-zero orthogonal modulation.

We propose and experimentally demonstrate a polarization shift keying label and a vestigial sideband carrier-suppressed return-to-zero payload scheme for a 43 Gbit/s all-optical label switching network. This scheme has a narrow channel bandwidth and a low penalty due to polarization mode dispersion impairments, which confirm it as a candidate technique for the next generation of optical networks.

Journal Article↗

PubMed2006

Wideband multichannel dispersion compensation based on a strongly chirped sampled Bragg grating and phase shifts.

A novel multichannel dispersion compensator based on a strongly chirped sampled Bragg grating with phase shifts is demonstrated experimentally. With a single phase mask, various channel spacings and dispersion can be achieved by proper control of the sampling period and the phase shifts. A 100 GHz channel-spacing compensator with a dispersion of -1000 ps/nm and another 200 GHz channel-spacing compensator with a dispersion of -500 ps/nm are designed. As an example, a 40 channel, 100 GHz channel-spacing compensator with a dispersion of approximately -560 ps/nm is fabricated. All the designs are based on one phase mask, thus showing the flexibility of our method.

Journal Article↗

PubMed2004

Sampled Bragg grating with desired response in one channel by use of a reconstruction algorithm and equivalent chirp.

The reconstruction algorithm is first applied to a sampled Bragg grating (SBG) with chirp in the sampling period. This method is demonstrated to achieve various profiles of both reflection and group delay within one channel of the SBG. This method has the advantage that the phase mask does not need any chirp, and only submicrometer precision is needed in the fabrication process. Based on this method, a tunable dispersion compensator is fabricated with a tuning range of 300 ps/nm in a flat band of 1 nm.

Journal Article↗

PubMed2002

New approach for enlargement of medical electronic endoscopic images.

To compensate for the imperfections of the endoscopic mechanical structure and the limitations of working space, a new technology based on the recursive minimum/maximum method is proposed to enlarge images obtained by the medical electronic endoscope. This method can be used repeatedly to obtain image enlargement to 2x by optimizing the neighborhood information of the pixels of interest in adjustable windows. In order to ensure the best evaluation of the pixel, the algorithm criterion is presented to decide whether the new gray value is assigned to the pixel. Experimental results from enlarged endoscopic images are presented that demonstrate that the recursive minimum/maximum method for image enlargement can preserve the fine details with rich edge information and with better visualization.

Algorithms↗