Kangping Zhong

Simultaneous Clock Enhancing and Demultiplexing for 160-Gb/s OTDM Signal Using Two Bidirectionally Operated Electroabsorption Modulators

We demonstrate a technique for performing optical time-division simultaneous clock enhancing and demultiplexing using two bidirectionally operated electroabsorption modulators (EAMs). The performance of the proposed setup is verified experimentally in a 160-Gb/s 100-km transmission system. The 10-GHz clock component is enhanced before launching into the clock recovery module. The recovered 10-GHz clock signal is featured with low timing jitter ( <;300 fs) and error-free transmission is achieved with the power penalty of ~ 0.9 dB. The proposed setup has merits of simultaneously enhancing base clock component and demultiplexing.

Experimental study on temperature dependence of dispersion of G.652 fiber and its effect on high-speed optical communication system and compensation

Temperature dependence of dispersion of G.652 fiber is experimental studied. The dispersion and dispersion slop variations over a temperature rang of 80°C, from -20°C to 60°C are measured. The effects of temperature dependence of dispersion on 80Gbit/s 100km OTDM system is experimental studied. Eye diagrams ascribed to the temperature of -20°C, 0°C, 20°C, 40°C, 60°C are demonstrated after 100km transmission link. The effect was also evaluated by BER curves. At last, dispersion thermal coefficient and dispersion slope thermal coefficient of dispersion compensating fiber were experimentally measured. The possibility of dynamically compensating chromatic dispersion and chromatic dispersion slope of G.652 fiber due to environmental temperature alterations by controlling the temperature of dispersion compensating fiber is proposed.

Experimental demonstration of 2×80-Gbit/s OTDM multi-channel add-drop multiplexing in a single fiber

In this paper, we experimentally demonstrate simultaneously all-optical optical time division multiplexing (OTDM) add-drop multiplexing (ADM) operation of two 80-Gbit/s OTDM signals by using a single highly nonlinear fiber (HNLF). The performance of ADM is experimental studied. The experimental results show that only a power penalty of 1.5dB for the channel dropping function and no distinct power penalty for the adding function.

160 Gb/s OTDM demultiplexing based on two cascaded electro-absorption sampling windows

One 160 Gb/s optical time division demultiplexer based on two cascaded electro-absorption modulators as sampling windows was demonstrated and experimentally studied in detail. The two stages were used for the 160 Gb/s into 40 Gb/s demultiplexing and 40 Gb/s into 10 Gb/s demultiplexing respectively.

Tunable chromatic dispersion compensating in 40-Gbit/s system by an enhanced thermal chirping fiber Bragg grating

In this letter, a tunable chromatic dispersion compensating in 40Gbit/s system based on enhanced thermal chirping fiber Bragg grating is demonstrated. The dynamic dispersion is provided by a tunable dispersion compensator based on enhanced thermal chirping fiber Bragg grating, which can change the group velocity delay (GVD) without changing the center wavelength or change the center wavelength with a fixed group velocity delay (GVD).

A novel simultaneous demultiplexing and clock recovery unit for high speed OTDM system

In this letter, a novel simultaneous demultiplexing and clock recovery unit based on EAMs and clock recovery module is presented and experimentally demonstrated for a high speed OTDM system. The 10GHz clock signal with low jitter is extracted from 80Gbit/s and 160Gbit/s OTDM signal, and every channel of the OTDM signal is successfully demultiplexed using this unit. The power penalty is lower than 3dB at BER of 10-9.

Stable error-free single channel 160-Gb/s OTDM 100-km transmission via high-precision dispersion management

A single channel with a 160-Gb/s optical time-division-multiplexing (OTDM) transmission over 100 km is fabricated. With the help of 500-GHz optical sampling oscilloscopes, the fiber length is adjusted to the order of 10 m, which corresponds to the accuracy of 0.4 ps for the dispersion compensation. The dispersion map is optimized for the 100-km transmission link. A completely error-free transmission with the power penalty of 3.6 dB is achieved for 2 h without using forward error correction.

A novel demultiplexer based on SOAs-MZI using couplers of space structure

In this paper, we propose an all optical OTDM demultiplexer basing on a novel Mach-Zehnder interferometer. The principle for demultiplexing is similar to the normal SOAs based MZI demultiplexer. Differing from the normal one, we creatively utilize a combination of fiber and space structure which is made by using thin membrane plating technology in GRIN lens, instead of the fused tapered fiber couplers of the general form. It has advantages of polarization insensitivity, broadband, high temperature stability. Utilizing this novel structure, 10Gbit/s tributary signal demultiplexed from 40Gbit/s signal is successfully demonstrated.

Study on the polarization scrambling time for ultra-high-speed optical fiber communication systems

A 160Gbit/s optical time-division-multiplexing (OTDM) transmission system with polarization Scrambler is demonstrated experimentally. The Scrambler based on the structure of the all-fiber dynamic polarization controller (PolaRITE II by General Photonics Co.). The polarization controller is controlled accurately the peak scrambling frequencies and the corresponding half-wave voltages by home-made a singlechip circuit. Both theory and experience show that the rate of scrambler is related to the spectrum width, spectral distribution, modulation rate and so on. The rate of Scramble for broadband light would be much slower compare with narrowband light to carrying out depolarization. In the same width of spectrum, light with abundant spectrum would need a slower rate. The relationship between the Rate of Scrambler and the Character of different Lasers will be discussed by using Stokes parameters and Mueller matrix. And the experiments performed to verify the results of theoretical analysis results. The Scrambler can reduce Intersymbol Interference, Polarization Mode Dispersion (PMD) and Polarization Dependent Loss (PDL) that have are validated experimentally. Based on the Scrambler, the 160-Gb/s OTDM transmissions are successfully demonstrated.

Demonstration of 80Gbit/s all-optical SOA-based wavelength conversion

All-optical SOA-based non-inverted wavelength conversion of 80Gbit/s by using a structure which consists of a SOA and a followed optical filter is demonstrated. Result illustrates that SOA-based wavelength converter has a weak nonlinear performance if the optical pulse with a wide spectrum. Moreover, a non-inverted 40Gbit/s and non-inverted 80Gbit/s All-optical wavelength conversion using this simple structure with a narrow spectrum are also demonstrated. Result shows shat the wavelength conversion at 40Gbit/s can be easily achieved, the wavelength converted eye diagram is clear. However, the eye diagram is not very clear at 80Gbit/s due to the performance of filter.