Miquel Rudé

ICFO Institute of Photonic Sciences | icfo · Optoelectronics

We report the interferometric photodetection of a phase-diffusion quantum entropy source in a silicon photonics chip. The device uses efficient and robust single-laser accelerated phase diffusion methods, and implements the unbalanced Mach-Zehnder interferometer with optimized splitting ratio and photodetection, in a 0.5 mm×1 mm footprint. We demon...

We report an accelerated laser phase diffusion quantum entropy source with all non-laser optical and optoelectronic elements implemented in silicon photonics. The device uses efficient and robust single-laser accelerated phase diffusion methods, and implements the whole quantum entropy source scheme including an unbalanced Mach-Zehnder interferomet...

Perfect light absorption over wide angles is possible in a multilayer structure, including Au or Ni metal and Ge2Sb2Te5 (GST) phase change material, without the need of sophisticated lithography. The GST layer also permits deep modulation of the absorption when it undergoes a phase transition.

In this paper we examine the ultrafast optical response of the crystalline and amorphous phases of the phase change material Ge$_2$Sb$_2$Te$_5$. By simultaneously recording the changes in the transmissivity and reflectivity of thin film samples, we obtain the time-dependent evolution of the dielectric function for the two phases. By analyzing the r...

The extreme electro-optical contrast between crystalline and amorphous states in phase-change materials is routinely exploited in optical data storage and future applications include universal memories, flexible displays, reconfigurable optical circuits, and logic devices. Optical contrast is believed to arise owing to a change in crystallinity. He...

The phenomenon of extraordinary optical transmission {EOT} through arrays of nanoholes patterned in a metallic film has emerged as a promising tool for a wide range of applications, including photovoltaics, nonlinear optics, and sensing. Designs and methods enabling the dynamic tuning of the optical resonances of these structures are essential to b...

The ability to manipulate light propagation at the nanoscale is of vital importance for future integrated photonic circuits. In this work we exploit the high contrast in the optical properties of the phase change material Ge2Sb2Te5 to control the propagation of surface plasmon polaritons at a Au/SiO2 interface. Using grating couplers, normally inci...

The large contrast in the optical and electronic properties between the amorphous and crystalline states of phase change materials is routinely exploited in modern technology, and their versatility, speed, and scalability are driving the development of new devices. Despite their widespread use, the explanation for the state transformation mechanism...

We use ultrafast optics and electron diffraction to measure irreversible amorphization of crystalline Ge2Sb2Te5 phase change films. We find that light directly modifies the local bonding environment leading to a hardening of bonds.

An optical switch operating at a wavelength of 1.55 μm and showing a 12 dB modulation depth is introduced. The device is implemented in a silicon racetrack resonator using an overcladding layer of the phase change data storage material Ge2Sb2Te5, which exhibits high contrast in its optical properties upon transitions between its crystalline and amo...