We present the phase-locking and coherence properties between two weakly coupled lasers. We show how the degree of coherence between the two lasers can be enhanced by nearly 1 order of magnitude after taking into account the effects of coupling on both their phases as well as their amplitudes. Specifically, correlations between synchronized spikes in the amplitude dynamics and the phase dynamics of the lasers allow for an interference pattern with a fringe visibility of 90%, even when the coupling strength is far below the critical value and they are not phase locked.
© 2011 Optical Society of America
Lasers and Laser Optics
Original Manuscript: December 16, 2010
Revised Manuscript: February 7, 2011
Manuscript Accepted: March 10, 2011
Published: April 5, 2011
M. Nixon, M. Fridman, A. A. Friesem, and N. Davidson, "Enhanced coherence of weakly coupled lasers," Opt. Lett. 36, 1320-1322 (2011)