Observation of counterclockwise, clockwise and butterfly bistabilty in 1550 nm VCSOAs

Abstract

In this paper, we report counter-clockwise, clockwise, and, for the first time to our knowledge, butterfly bistability in 1550 nm Vertical Cavity Semiconductor Optical Amplifiers (VCSOA). Bistable operation is experimentally observed for bias currents ranging from 66-122% of threshold with switching powers as low as 2 microW. These switching powers are two orders of magnitude lower than any previous results in 1550 nm VCSOAs. These switching powers are consistent with previous reports on optical bistability in 850 nm VCSOAs and provide an important step towards the realization of small footprint, low power optical logic/switching elements in the 1550 nm wavelength band.

Bistability patterns and nonlinear switching with very high contrast ratio in a 1550 nm quantum dash semiconductor laser

“…[11][12][13] Furthermore, for edge-emitting devices biased above threshold, anticlockwise OB had only been reported, 13 while the occurrence of clockwise or other types of bistability has only been measured when biased below threshold. 11,12 Surprisingly, the results obtained with a nanostructure QDash FP laser show stronger similarities to those reported for QW verticalcavity devices, VCSELs and VCSOAs, [16][17][18][19] with completely different structure and characteristics compared to the QDash FP laser used in this work. In those works with QW vertical-cavity devices, clockwise NS and OB were also observed as the initial detuning was increased.…”

“…In those works with QW vertical-cavity devices, clockwise NS and OB were also observed as the initial detuning was increased. [17][18][19][20] We believe there are two important factors explaining these emerging differences with previous results in edgeemitting lasers as well as the similarities with results reported for vertical-cavity devices. First, the relatively lower values of linewidth enhancement factor (a) reported for nanostructure lasers 30 comparable to those reported for QW VCSELs.…”

“…These include all-optical logic gates, [3][4][5] all-optical flip-flop, 6 optical signal regeneration, 7 optical switching, 8 wavelength conversion, 9 optical buffer memory, 10 etc. The range of laser structures where OB and NS has been investigated includes devices with bulk or quantum-well (QW) active regions, such as edge-emitting lasers, Fabry-Perot (FP) [11][12][13] and distributed feedback (DFB) 8,14,15 and also vertical-cavity devices, i.e., vertical cavity surface emitting lasers (VCSELs), 16,17 and vertical cavity semiconductor optical amplifiers (VCSOAs) [18][19][20] (for a review see Refs. 1 and 2 and references therein).…”

“…These record values of reflective optical power switching and bistability are at least one order of magnitude higher than any previously reported for other types of semiconductor lasers and laser amplifiers including bulk or quantum well edge-emitting or verticalcavity devices. [11][12][13][14][15][16][17][18][19] We must note that the peak power of the reflective signal was used to determine the on-off contrast ratio. We believe that this technique is in fact conservative.…”

An analytical study on bistability of Fabry-Perot semiconductor optical amplifiers

“…In [3], the authors presented a commonly-used model for investigating the bistability in SOAs. By use of this model, the static and dynamic bistable characteristics in different types of SOAs have been investigated substantially [3][4][5][6][7][8]. However, these studies have been performed either numerically or experimentally.…”