Title :
All-optical logic based on ultrafast gain and index dynamics in a semiconductor optical amplifier
Author :
Dorren, H.J.S. ; Xuelin Yang ; Mishra, A.K. ; Zhonggui Li ; Heongkyu Ju ; de Waardt, H. ; Khoe, G.-D. ; Simoyama, T. ; Ishikawa, H. ; Kawashima, H. ; Hasama, T.
Author_Institution :
COBRA Res. Inst., Eindhoven Univ. of Technol., Netherlands
Abstract :
We investigate nonlinear carrier dynamics in a multiquantum-well semiconductor optical amplifier (SOA) in the context of ultrafast all-optical logic. A rate-equation model is presented that accounts for two-photon absorption, free-carrier absorption, self- and cross phase modulation, carrier heating, spectral, spatial hole burning, and self- and cross polarization modulation. The nonlinear refractive index dynamics is investigated theoretically and experimentally. We find nonlinear phase changes larger than /spl pi/ radians, which recovers on a timescale in the order of 1 ps. We also investigate a nonlinear AND gate that consists of an SOA that is placed in an asymmetric Mach-Zehnder interferometer. We show that the gate can be operated using 800-fJ optical pulses with duration of 200 fs while having a contrast ratio larger than 11 dB.
Keywords :
Mach-Zehnder interferometers; high-speed optical techniques; light polarisation; logic gates; optical hole burning; optical logic; quantum well lasers; refractive index; self-phase modulation; semiconductor device models; semiconductor optical amplifiers; two-photon processes; 200 fs; 800 fJ; all-optical logic; asymmetric Mach-Zehnder interferometer; carrier heating; cross phase modulation; cross polarization modulation; free-carrier absorption; multiquantum-well semiconductor optical amplifier; nonlinear AND gate; nonlinear carrier dynamics; nonlinear refractive index dynamics; rate-equation model; self-phase modulation; self-polarization modulation; spatial hole burning; spectral hole burning; two-photon absorption; ultrafast gain; Logic; Nonlinear optics; Optical interferometry; Optical refraction; Optical signal processing; Optical variables control; Refractive index; Semiconductor optical amplifiers; Stimulated emission; Ultrafast optics; Optical logic; optical signal processing ultrafast carrier dynamics; semiconductor optical amplifier;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/JSTQE.2004.835293