Title :
Optimization of an Asymmetric DFB Laser Used as All-Optical Flip-Flop
Author :
Abbasi, A. ; Roelkens, G. ; Morthier, G.
Author_Institution :
imec, Photonics Res. Group, Ghent Univ., Ghent, Belgium
Abstract :
We have numerically optimized the speed of an all-optical flip-flop based on an antireflection-coated λ/4 phaseshifted distributed feedback (DFB) laser. Numerical results show that by engineering the grating of the DFB laser and making the coupling coefficient asymmetrical, fall times reduce by a factor of 2 compared with a standard laser design. It is also shown that the confinement factor in the quantum wells and the length of the laser cavity have a significant impact on the flip-flop operation. The switching between two states can be realized using pulses with energies below 125 fJ and with a duration of 10 ps. The switching time can be reduced to 5 ps and the switching rate increased up to 10 GHz.
Keywords :
antireflection coatings; diffraction gratings; distributed feedback lasers; flip-flops; laser cavity resonators; numerical analysis; optical couplers; optical phase shifters; optical switches; optimisation; quantum optics; quantum wells; semiconductor lasers; all-optical flip-flop; antireflection-coated λ/4 phase-shifted laser; asymmetric DFB laser; asymmetric coupling coefficient; grating engineering; laser cavity; numerical optimization; optical switching; quantum wells; time 10 ps; Couplings; Laser beams; Lasers; Optical bistability; Optical packet switching; Optical switches; All-optical flip-flops; Distributed feedback (DFB) lasers; distributed feedback (DFB) lasers; optical bistability;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2014.2378376
