Fabrication of 3D Photonic Crystals toward Arbitrary Manipulation of Photons in Three Dimensions

Abstract

Abstract:The creation of large-area, unintentional-defect-free three-dimensional (3D) photonic crystals in the optical regime is a key challenge toward the realization of the arbitrary 3D manipulation of photons. In this article, we discuss an advanced fabrication method of 3D silicon photonic crystals based on the highly accurate alignment and wafer bonding of silicon-on-insulator (SOI) wafers. We introduce an advanced alignment system, in which the alignment process is automated by image recognition and feed-back control of stages, and show that it achieves an alignment accuracy better than~50 nm. The bonding of SOI wafers is also investigated to obtain 3D crystals composed of highly pure crystalline silicon. We show the fabrication results of large-area 3D photonic crystals based on such considerations and demonstrate the successful introduction of artificial defects as functional components, such as coupled waveguide pairs or waveguides/nanocavities. We expect that these will be pioneering results toward the arbitrary 3D control of photons using 3D photonic crystals.

Supraballs as spherical solid 3D superlattices of hydrophobic nanocrystals dispersed in water: nanoarchitectonics and properties

“…This clearly shows that the drop of the supraball absorption is related to the formation of 3D photonic crystals. 32,33 The energy flow upon light irradiation is investigated by pump-probe experiments. 35 The differential transmission (DT/T) spectra are recorded as a function of time and the probe wavelength, l. At the initial time scale of ten picoseconds, the typical DT/T map is attributed to the transient spectra of the dispersed nanocrystals at various probe wavelengths.…”

“…This clearly shows that the drop of the supraball absorption is related to the formation of 3D photonic crystals. 32,33…”

Deep Reactive Ion Etching of Cylindrical Nanopores in Silicon for Photonic Crystals

“…Etching of nanopores in silicon is of interest in the research of micro-sieves [1], optical sensors [2], x-ray mirrors [3], photovoltaics, [4] photonic crystals, [5][6][7] and many more topics.…”

“…[14] Tuning the nanopore diameter and pitch of the pores allows one to control the position and width of the photonic band gap, comparable to how doping changes the electronic band gap in semiconductors. For the fabrication of both 2D [15,16] and 3D silicon photonic crystals, [5,7] it is important to have good control over the shape, diameter, length and roughness of the side wall of the nanopores. For certain classes of photonic crystals, the etched structures must be as close to a perfect cylinder of a precise diameter as possible, that is, little to no tapering, minimal scalloping and no under etch.…”

A tunable waveguide-coupled cavity design for scalable interfaces to solid-state quantum emitters

“…x alignment must be within ±30 nm to maintain an enhancement ≥90% of the maximum. Various pick-and-placement techniques have already been demonstrated with excellent in-plane alignment, including optical microscopy with better than 200 nm in-plane tolerance 32,49 and scanning-electron microscope based alignment with 25 nm tolerance, [50][51][52][53] aided by lithographically defined alignment structures as indicated in Figure 1(a). Finally, any remaining error is correctable in situ using AlN NEMS actuators in x and y directions.…”