Optical Flip-Flop Operation in Orthogonal Polarization States with a Single Semiconductor Optical Amplifier and Two Feedback Loops

Kenta TAKASE  Rie UEHARA  Nobuo GOTO  Shin-ichiro YANAGIYA  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E97-C   No.7   pp.767-772
Publication Date: 2014/07/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E97.C.767
Type of Manuscript: Special Section PAPER (Special Section on Opto-electronics and Communications for Future Optical Network)
Category: 
Keyword: 
all-optical flip-flop,  semiconductor optical amplifier,  orthogonal polarization,  

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Summary: 
An optical flip-flop circuit with a single semiconductor optical amplifier (SOA) using two orthogonal polarization states is proposed. The optical set / reset input and output signals are at a single wavelength. The flip-flop circuit consists of an SOA, a polarization combiner, a polarization splitter, two directional couplers, and two phase shifters. No continuous light source is required to operate the circuit. In this paper, we theoretically analyze the operation performance. Polarization dependence in SOA is considered in the analysis at a single wavelength operation, and numerically simulated results are presented. We confirm that the flip-flop circuit with a feedback-loop length of 15 mm can be operated at switching time of around 3 ns by 1 ns set / reset pulses. The flip-flop performance is discussed from viewpoints of transient overshoot and contrast at the steady on-off states.