Nanoscale waveguiding methods

Abstract

While 32 nm lithography technology is on the horizon for integrated circuit (IC) fabrication, matching the pace for miniaturization with optics has been hampered by the diffraction limit. However, development of nanoscale components and guiding methods is burgeoning through advances in fabrication techniques and materials processing. As waveguiding presents the fundamental issue and cornerstone for ultra-high density photonic ICs, we examine the current state of methods in the field. Namely, plasmonic, metal slot and negative dielectric based waveguides as well as a few sub-micrometer techniques such as nanoribbons, high-index contrast and photonic crystals waveguides are investigated in terms of construction, transmission, and limitations. Furthermore, we discuss in detail quantum dot (QD) arrays as a gain-enabled and flexible means to transmit energy through straight paths and sharp bends. Modeling, fabrication and test results are provided and show that the QD waveguide may be effective as an alternate means to transfer light on sub-diffraction dimensions.

Modeling and simulation of a nanoscale optical computing system

“…Furthermore, most components of OLEs including quantum dots [1,2,33,22], waveguides [32] and color filters [21] have been individually demonstrated and are all silicon compatible. The only component that has not been demonstrated is the evanescent coupling of chromophores to waveguides.…”

“…Due to the above properties, optical waveguides are commonly used in on-chip networks [15,17]. Moreover, the smaller size of waveguides, such as nanoscale waveguiding [32] have been demonstrated in recent years.…”

Simulation of complex plasmonic circuits including bends

“…Similarly, curved hybrid LRSPP metal strips reach smaller radii than non hybrid ones for the same total bending loss, even with only two-dimensional dielectric waveguides [7]. This might be desirable for integrated optical circuits [16][17][18][19]. Simulation techniques are essential for the design and practical implementation of such photonic circuits based on plasmonic waveguides.…”

Passive linear nanoscale optical and molecular electronics device synthesis from nanoparticles

“…One-dimensional arrays consisting of chromophores, quantum dots, or metal nanoparticles, spaced within nanometers of each other, have been fabricated. Such arrays have been proposed for use as transmission lines to transport electromagnetic energy in the form of plasmons or excitons either by coherent or diffusive means [1,2]. Such light guides can confine electromagnetic energy to length scales smaller than the diffraction limit, a feature that is attractive for high-component-density optical devices.…”