Fast all-optical switching using ion-implanted silicon photonic crystal nanocavities

Abstract

On-chip all-optical switching based on the carrier plasma dispersion in an argon ion (Ar+) implanted photonic crystal (PhC) nanocavity that is connected to input/output waveguides is described. A high dose of Ar+ is introduced, and annealing is used to recrystallize the silicon and thus create dislocation loops at the center of the PhC slab. Dislocation loops enable the fast recombination of the carriers, which allows a fast switching recovery time for PhC switches. The switching window (∼70ps) is three times smaller than that without ion implantation, while the required operating energy remains almost the same (<100fJ).

Liquid Crystals into Planar Photonic Crystals

“…In Section 4, we will show how the optical response of PhC devices infiltrated with nematic LCs can be tuned by temperature, electric field and optical irradiation El-Kallassi et al, 2007). In particular, we observe that, in spite of a large amount of research on LC infiltrated PhCs, little has been done on their optical tuning (Maune et al, 2005), even though all-optical switching plays a very important role in the optical communication field (Asakawa et al, 2006) and, as we have briefly discussed above, several other approaches have already been explored to optically tune planar PhCs (Ndi et al, 2005;Raineri et al, 2005;Teo et al, 2006;Tanabe et al, 2007). Here, we will illustrate how it is possible to optically tune the response of planar PhC devices by infiltration with a photo-responsive LC blend doped with azobenzene photochromic molecules (Legge & Mitchell, 1992;Sung et al, 2002;Ikeda, 2003).…”

“…by means of carrier injection) and non-resonant (i.e. by exploiting the Kerr effect) optical pumping (Haché & Bourgeois, 2000;Leonard et al, 2002;Baba et al, 2003;Ndi et al, 2005;Raineri et al, 2005;Britsow at al., 2006;Hu et al, 2006;Ndi et al, 2006;Teo et al, 2006;Hu et al, 2007;Tanabe et al, 2007). When either magnetic or ferro-electric or electro-optic non-linear materials are used to fabricate PhC devices, external magnetic or electric fields can be applied, respectively, to adjust the optical response (Kee et al, 2000;Lyubchanskii et al, 2003;Scrymgeour et al, 2003;Belotelov & Zvezdin, 2005).…”

Design of a tunable, room temperature, continuous-wave terahertz source and detector using silicon waveguides

“…Several methods have been demonstrated for electrically sweeping excess carriers from a silicon waveguide to reduce effective carrier lifetime [34,35]. Additionally, it has been demonstrated that ion implantation of Ar + ions can reduce the free-carrier lifetime to 100 ps [36], which would amount to a decrease in the nonlinear loss that our waveguides experience by a factor of 10. This approach could also be easily integrated into our process, since it does not require any change in the waveguide geometry or electrical contact.…”

Ultrafast low-energy all-optical switching using a photonic-crystal asymmetric Fano structure

“…It was also found that the non-monotonous frequency-dependence of the Fano transmission spectrum implies an inherent reduction of patterning effects. In contrast, a Lorentzian spectrum, with its monotonously-varying tails, converts (slow) dynamics of the resonance shift into amplitude modulation, limiting the bitrate due to the long carrier lifetime [9]- [14]. It is seen that the Fano structure has a considerably larger eye opening than the Lorentzian structure, which is ascribed to the suppression of the slow decay component.…”