42.7K
views
38
authors
8
articles
Editors
4
Impact
Loading...
(A) Relative peak shift for total filling vs n and integrated relative intensity ≃ 550–850 nm as a function of the low-frequency dielectric constant of the solvent for a PS microcavity initially centered at 570 nm. From Ref. [104]. (B) Simultaneous measurement of the optical and the electrical response to humidity and NO2. Left plot: response to two different humidity values in the absence of NO2. Right plot: response to 50 ppb of NO2 in presence of 20% humid air. From Ref. [105] (C) Dynamic response of the sensor to different concentrations of NO2 in dry air. From Ref. [106]. (D) Scattering ring pattern of a fresh PS layer (solid line) and the same after thermal annealing (dashed line) under unpolarized illumination. β is the birefringence parameter. From Ref. [107]. (E) Scheme of the setup used for the optical characterization of PS membranes. Transmission spectra for empty pores (black line), and pores completely filled with isopropanol (green line) and ethanol (blue line). Birefringence data from the measured spectra (dots) and simulated curves using the Bruggeman model (dashed lines) for isopropanol (green) and ethanol (blue). From Ref. [108].
Review
06 December 2021

Silicon Photonics, the technology where optical devices are fabricated by the mainstream microelectronic processing technology, was proposed almost 30 years ago. I joined this research field at its start. Initially, I concentrated on the main issue of the lack of a silicon laser. Room temperature visible emission from porous silicon first, and from silicon nanocrystals then, showed that optical gain is possible in low-dimensional silicon, but it is severely counterbalanced by nonlinear losses due to free carriers. Then, most of my research focus was on systems where photons show novel features such as Zener tunneling or Anderson localization. Here, the game was to engineer suitable dielectric environments (e.g., one-dimensional photonic crystals or waveguide-based microring resonators) to control photon propagation. Applications of low-dimensional silicon raised up in sensing (e.g., gas-sensing or bio-sensing) and photovoltaics. Interestingly, microring resonators emerged as the fundamental device for integrated photonic circuit since they allow studying the hermitian and non-hermitian physics of light propagation as well as demonstrating on-chip heavily integrated optical networks for reconfigurable switching applications or neural networks for optical signal processing. Finally, I witnessed the emergence of quantum photonic devices, where linear and nonlinear optical effects generate quantum states of light. Here, quantum random number generators or heralded single-photon sources are enabled by silicon photonics. All these developments are discussed in this review by following my own research path.

19,142 views
22 citations