Subpicosecond Optical Switching with a Negative Index Metamaterial

Abstract

We demonstrate a nanoscale, subpicosecond (ps) metamaterial device capable of terabit/second all-optical communication in the near-IR. The 600 fs response, 2 orders of magnitude faster than previously reported, is achieved by accessing a previously unused regime of high-injection level, subpicosecond carrier dynamics in the α-Si dielectric layer of the metamaterial. Further, we utilize a previously unrecognized, higher-order, shorter-wavelength negative-index resonance in the fishnet structure, thereby extending device functionality (via structural tuning of device dimensions) over 1.0−2.0 μm. The pump energy required to modulate a single bit is only 3 nJ over our current 700 μm2 area device and can be easily scaled into the picoJoule regime with smaller cross sectional areas.

Reversible modulation and ultrafast dynamics of terahertz resonances in strongly photoexcited metamaterials

“…13,14,19 Two outstanding issues are still poorly understood: first, there lack insights on how high density photoexcited carriers modify the dynamic responses of metamaterials; second, the decay pathway of photoexcited metamaterials after femtosecond (fs) excitation is not explicitly studied, and, particularly, the temporal evolution of the transient states have only been understood as a density-independent relaxation back to the equilibrium.…”

Non-Unity Permeability in InP-Based Photonic Device Combined with Metamaterial

“…The other strategy is to combine semiconductor devices with metamaterials. Leading examples are the Si-based modulator which enables active tuning of metamaterial [20][21][22] and the III-V semiconductor-based waveguide in which relative permeability is not unity [23,24]. The latter in particular is now the focus of attention because it is compatible with other standard waveguide-based optical devices such as lasers.…”

Channeling light into quantum-scale gaps

“…1,3 A well-known example of the light-concentrating ability of metals is the phenomenon of extraordinary optical transmission (EOT) through subwavelength metallic holes with sizes on the order of 100 nm. [4][5][6] Squeezing light through these tiny gaps has inspired important applications including advanced optical lithography, 7 EOT-assisted bio-sensing, 8 sub-ps switching in metamaterials, 9 and plasmonic enhanced detectors. 10 These efforts are significant demonstrations of new functionalities enabled by extreme light concentration.…”