Publications de Joab Di Francesco

On-chip near-infrared optical spectrometer based on single-mode Epo waveguide and gold nanoantennas

Irène Antoinette Philipoussis, Toralf Scharf, Joab Di Francesco, Maurine Malak Karam Awadallah

We report about optical spectrometry using gold nanostructures printed on top of an integrated optical waveguide. The optical waveguide is a single-mode buried waveguide made from a combination of photo-polymerizable materials and is fabricated by photolit ...

Spie-Soc Photo-Optical Instrumentation Engineers2014

Manipulating Bloch surface waves in 2D: a platform concept-based flat lens

Hans Peter Herzig, Elsie Barakat, Libo Yu, Tristan Sfez, Lubos Hvozdara, Joab Di Francesco

At the end of the 1970s, it was confirmed that dielectric multilayers can sustain Bloch surface waves (BSWs). However, BSWs were not widely studied until more recently. Taking advantage of their high-quality factor, sensing applications have focused on BSW ...

Nature Publishing Group2014

Silicon based micro-optical collimating element for mid-infrared Quantum Cascade Lasers

Hans Peter Herzig, Lubos Hvozdara, Pierre-Yves Baroni, Joab Di Francesco, Antoine Muller

A realization of a high numeric aperture, aspheric, silicon based collimating element for the mid-infrared (4 – 14 microns) Quantum Cascade Lasers, suited for mass production using computer driven reactive ion etching is presented. ...

2012

High numerical aperture silicon collimating lens for mid-infrared quantum cascade lasers manufactured using wafer-level techniques

Hans Peter Herzig, Lubos Hvozdara, Pierre-Yves Baroni, Joab Di Francesco, Antoine Muller

We present an aspheric collimating lens for mid-infrared (4-14 µ) quantum cascade lasers. The lenses were etched into silicon by an inductively coupled plasma reactive ion etching system on wafer level. The high refractive index of silicon reduces the heig ...

2012

CO2 isotope sensor using a broadband infrared source, a spectrally narrow 4.4 μm quantum cascade detector, and a Fourier spectrometer

Hans Peter Herzig, Lubos Hvozdara, Joab Di Francesco

We report a prototype CO2 gas sensor based on a simple blackbody infrared source and a spectrally narrow quantum cascade detector (QCD). The detector absorption spectrum is centered at 2260 cm−1 (4.4 μm) and has a full width at half maximum of 200 cm−1 (25 ...

2011

Si-interdiffusion in heavily doped AlN-GaN-based quantum well intersubband photodetectors

Nicolas Grandjean, Denis Martin, Joab Di Francesco

We demonstrate the effect of rapid thermal annealing on heavily Si-doped AlN/GaN quantum wells. After 1000 degrees C annealing during 5, 10, and 20 min, the dominant effect was interdiffusion of Si rather than intermixing between the Al and Ga atoms. Both ...

AIP American Institute of Physics2011