Squeezing Light in Wires: Fundamental Optical Properties of Si Nanowire Waveguides

Abstract

Single-mode Si-wire waveguides, fabricated in the Si-on-insulator (SOI) platform, are the basis for a growing number of potential applications in linear and nonlinear integrated optical devices and systems. This paper reviews the fundamental optical physics and behavior of these waveguides and demonstrates how their reduced transverse dimensions and index contrast lead to a series of unique and distinct modal properties. These properties include readily tunable waveguide dispersion (including dispersion flattening), large longitudinal fields, a decrease in group velocity over those of the bulk materials, and anisotropic nonlinear optical properties. In turn, new devices and device structures are achievable as a result of these features and examples of new device structures are provided. …………

Flexible integration of free-standing nanowires into silicon photonics

“…It features a variety of advantages including large-scale manufacturability, high reproducibility, and high integration density. Similar to the advancement of integrated electronics with the feature width of interconnect decreasing down to sub-10-nm level driven by Moore’s law 7 , 8 , size miniaturization of integrated photonics also develops rapidly for higher operation speed, less power consumption, and so on 9 – 11 . However, compared to electric current in a metal wire with relatively low frequency, optical frequency signals in a waveguide are much more sensitive to the surface roughness, leading to roughness-induced optical loss in top-down fabrication structures 12 .…”

BER in Slow-Light and Fast-Light Regimes of Silicon Photonic Crystal Waveguides: A Comparative Study

“…One promising alternative to the commonly used copper wires [3] are optical interconnects implemented in the silicon-on-insulator platform [4], [5], [6]. Importantly, due to the unique optical properties of silicon photonic waveguides (Si-PhWs) [7], [8], [9], employing silicon photonics based solutions for system interconnects does not simply amount to replacing copper wires with photonic wires, but they can also be used to implement key functionalities required by optical networks-on-chip. Thus, not only that Si-PhWs could facilitate ultrahigh bandwidth data communication [10], but also their strong dispersion and large optical nonlinearity allowed for the chip-level implementation of many functionalities, including optical modulators and switches [11], receivers [12], mode multiplexing [13], optical amplifiers [14], and frequency converters [15].…”

Simulation of Chirped Pulse Propagation in Silicon Nanowires: Shape and Spectrum Analysis

“…Low cost, availability as well as linear and nonlinear optical properties of silicon has caused silicon to be an ideal material for the production of nanoscale integrated photonic devices [1]- [6]. Large refractive index of silicon (n = 3.5) compared to the small refractive index of cladding (n = 1 for air and n = 1.45 for silica) leads to tight light confinement [1] [3]- [7].…”

“…Such strong light confinement, allows the waveguide silicon devices to have a very small cross-section in the order of nanometer and such devices are called silicon nanowires. Reduction of the nanoscale cross-section together with the high refractive-index contrast would lead to two distinct advantages: First, the ability to control the dispersion and high optical field intensity; Second, potential applications of silicon for nonlinear optics [1] [5] [6] [8]. Although silicon does not exhibit second-order nonlinear effects, it possesses a very high nonlinear optical third-order susceptibility, approximately 3 to 4 times larger than that of the silica [1] [5] [6].…”