Browsing by Author "Wu, X."

Now showing 1 - 4 of 4

Chromatic dispersion monitoring of 40-Gb/s RZ-DPSK and 80-Gb/s RZ-DQPSK data using cross-phase modulation in highly-nonlinear fiber and a simple power monitor
(2008-01-01)
Yang, J. -Y.
;
Zhang, L.
;
Wu, T.
;
Wu, X.
;
Christen, L. C.
We experimentally demonstrate an all-optical chromatic dispersion monitoring technique utilizing cross-phase modulation in highly-nonlinear fiber for 40-Gb/s RZ-DPSK. Maximum monitored power variation of 16.5-dB is achieved in the presence of up to 120-ps/nm chromatic dispersion. (C) 2008 Optical Society of America.
Equalization of PAM-4 Signal Generated by Silicon Microring Modulator for 64-Gbit/s Transmission
(2017-11-15)
Tzu, T. C.
;
Hsu, Y.
;
Chuang, C. Y.
;
Wu, X.
;
Chow, C. W.
We propose and demonstrate a 64-Gbit/s four-level pulse-amplitude-modulation transmission by using a limited modulation bandwidth silicon microring modulator (SiMRM) and the Volterra equalization scheme. Severe intersymbol interference caused by both the chromatic dispersion of the optical fiber and the bandwidth limitation of components can be compensated. Besides, several equalization schemes are compared and analyzed in terms of performance and complexity. In addition, the design and characteristics of the SiMRM used in the experiment are also discussed.
Single-exciton energy shell structure in InAs/GaAs quantum dots
(2008-12-01)
Awirothananon, S.
;
Raymond, S.
;
Studenikin, S.
;
Vachon, M.
;
Render, W.
The energy shell structure of a single exciton confined in a self-assembled quantum dot (QD), including excited states, is studied in a regime where the direct Coulomb attraction energy is comparable to the kinetic energy of the carriers. This is achieved via magnetophotoluminescence excitation spectroscopy experiments, where a magnetic field applied perpendicular to the plane of the QD is used to reveal the angular-momentum content of energy shells. The absorption spectrum of the QDs is modeled, and comparison with experiment allows us to relate the observed transitions to interband QD bound-state transitions. The blueshift of the absorption peaks compared to the emission peaks is then interpreted in terms of many-body interactions, and we show that for a highly symmetric situation, the observed energy difference gives a direct measurement of the extra exchange energy gained upon addition of an extra exciton in the QD.
Transmission Performance Improvement of PAM-4 Signal Direct-Detected by Ge-Si Photodiode using Volterra Equalization
(2017-01-01)
Hsu, Y.
;
Chuang, C. Y.
;
Chen, G. H.
;
Chang, Y. C.
;
Wu, X.
We demonstrate a 4-level pulse-amplitude-modulation (PANT-4) transmission system direct-detected by germanium-silicon (Ge-Si) photodiode (PD). Volterra-equalization is used to compensate signal distortion and 40-Gibt/s and 50-Gbit/s PANT-4 signals after 20-km and 10-km fiber transmissions are achieved.