Local digital etching and infiltration for tuning of a H1- Cavity in deeply etched InP/InGaAsP/InP photonic crystals

Local post-production processing of single holes in a planar photonic crystal is demonstrated by selectively opening a masking layer by focused ion beam milling. Local tuning was optically demonstrated by both blueshifting and subsequent red-shifting th

Wavelength-sized cavities in high aspect InP/InGaAsP/InP photonic crystals

The photonic properties of two classes of wavelength-sized cavities are reported for deeply etched InP/InGaAsP/InP planar photonic crystals. The high aspect, deeply etched structures are studied as potential building blocks for nonmembrane type photonic devices in standard InP photonic integrated circuits. The first class consists of cavities of one unit cell in one direction and varying size in the other planar direction. The studied class includes a Fabry–Perot type cavity with one row of missing holes, a simple single missing hole defect cavity, and a cavity consisting of two holes which have been slightly shifted and reduced in hole radius. The best observed quality factor of 65 in this class is obtained for a single hole defect cavity. The second class is comprised of cavities which are derived from a three missing row defect in one direction and varying size in the other direction. This includes a Fabry–Perot type cavity with three rows of missing holes, a point defect cavity consisting of seven unetched holes and a six hole ring cavity. The best observed quality factor of 300 is obtained for the ring cavity in this second class of structures, which is adequate for applications.Kavli Institute of NanoscienceApplied Science

Tuning of narrow-bandwidth photonic crystal devices etched in InGaAsP planar waveguides by Liquid Crystal infiltration

Photonic crystal (PC) devices in the InP/InGaAsP/InP planar waveguide system exhibiting narrow bandwidth features were investigated for use as ultrasmall and tunable building blocks for photonic integrated circuits at the telecom wavelength of 1.55 μm.

Beyond the EULA: Improving consent for data mining

Companies and academic researchers may collect, process, and distribute large quantities of personal data without the explicit knowledge or consent of the individuals to whom the data pertains. Existing forms of consent often fail to be appropriately readable and ethical oversight of data mining may not be sufficient. This raises the question of whether existing consent instruments are sufficient, logistically feasible, or even necessary, for data mining. In this chapter, we review the data collection and mining landscape, including commercial and academic activities, and the relevant data protection concerns, to determine the types of consent instruments used. Using three case studies, we use the new paradigm of human-data interaction to examine whether these existing approaches are appropriate. We then introduce an approach to consent that has been empirically demonstrated to improve on the state of the art and deliver meaningful consent. Finally, we propose some best practices for data collectors to ensure their data mining activities do not violate the expectations of the people to whom the data relate

Wavelength-sized, tunable nanocavity in deeply etched InP/InGaAsP/InP photonic crystals

Wavelength-sized point defect cavities coupled to access waveguides are reported for deeply etched InP/InGaAsP/InP two-dimensional photonic crystals. The observed quality factor of 60 is comparable to those found for one-row defect Fabry–Perot cavities and for simple point defect cavities in membranes. The quality factor was changed by varying the number of rows of holes. Upon infiltration of the holes with liquid crystal, frequency tuning was demonstrated.QN/Quantum NanoscienceApplied Science

InP-based planar photonic crystals infiltrated with solid polymers and liquid crystals

The filling is reported of the air holes of an InP-based two-dimensional photonic crystal with solid polymer and withliquid crystal 5CB. The polymer filling is obtained by thermal polymerization of an infiltrated liquid monomer,trimethylolpropane triacrylate. The filling procedure for both the monomer and liquid crystal relies on the capillaryaction of the liquid inside the ~ 200 nm diameter and > 2.5 ?m deep air holes. The solid polymer infiltration result wasdirectly inspected by cross-sectional scanning electron microscopy. It was observed that the holes are fully filled to thebottom. The photonic crystals were optically characterized by transmission measurements around the 1.5 ?mwavelength band both before and after infiltration. The observed high-frequency band edge shifts are consistent withclose to 100% filling, for both the polymer and the liquid crystal. No differences were observed for filling under vacuum or ambient, indicating that the air diffuses efficiently through the liquid infiltrates, in agreement with estimates based on the capillary pressure rise.Kavli Institute of NanoscienceApplied Science