Unidirectional III-V microdisk lasers heterogeneously integrated on SOI

Abstract

Abstract:We demonstrate unidirectional bistability in microdisk lasers electrically pumped and heterogeneously integrated on SOI. The lasers operate in continuous wave regime at room temperature and are single mode. Integrating a passive distributed Bragg reflector (DBR) on the waveguide to which the microdisk is coupled feeds laser emission back into the laser cavity. This introduces an extra unidirectional gain and results in unidirectional emission of the laser, as demonstrated in simulations as well as in experiment.

Unidirectional, widely-tunable and narrow-linewidth heterogeneously integrated III-V-on-silicon laser

“…We previously demonstrated the use of a DBR grating to couple the CW and CCW mode and thereby obtaining unidirectional operation in single wavelength micro-disk lasers as described in [21]. The theory behind the unidirectional behavior of such laser cavities is explained in [23].…”

“…A narrower linewidth can be achieved because of the absence of spatial hole burning [18][19], together with a more smooth output power versus wavelength characteristic, as there is no competition between the CW and the CCW mode. For these reasons several methods have been evaluated to reach unidirectional lasing, including the use of an S-bend waveguide structure inside the ring laser cavity [17], a snail shape laser [20] or an external reflector coupling the CW and the CCW mode [21]. The latter approach is followed in this paper.…”

Excitability in optically injected microdisk lasers with phase controlled excitatory and inhibitory response

“…The microdisk lasers simulated and discussed in this paper, consist of a disk-shape InP laser cavity, with a InAsP quantum well gain section, bonded on top of a Silicon-On-Insulator (SOI) substrate [18,19]. The modes are evanescently coupled to a silicon waveguide in the SiO 2 -substrate layer.…”

“…The lasers are electrically pumped and can be subject to optical injection from both sides through the coupling waveguide. One can describe the dynamic behavior of a microdisk laser using a set of coupled rate equations, in the slowly varying amplitude approach, representing the evolution of the complex mode amplitudes, E + and E − (|E ± | 2 is the number of photons in the mode, while the optical field oscillates with an additional e − jω in t -dependency), and the number of free carriers, N, in the cavity [17,19,25]:…”

“…Indeed, these microdisk lasers are fabricated using hybrid III-V on silicon technology [18,19], which makes the neurons highly scalable through techniques as wafer bonding [12,20,21]. Furthermore, they have a smaller footprint and lower power usage than many other integrated lasers and operate at higher speed [22].…”