Ultrafast nonlinear dynamics in thin GaN films studied by femtosecond digital holography

We studied the nonlinear propagation dynamics of intense 300 fs infrared pulses in thin GaN films by use of pulsed digital holography technique with 25 fs temporal resolution

Ultrafast nonlinear dynamics in thin GaN films studied by femtosecond digital holography

We studied the nonlinear propagation dynamics of intense 300 fs infrared pulses in thin GaN films by use of pulsed digital holography technique with 25 fs temporal resolution

A Binary-Weighted Photonic Digital-to-Analogue Converter

In fifth-generation (5G) mobile networks the available bandwidth and the range of carrier frequencies will be significantly larger than in current mobile networks. To cope with the consequent increase in traffic 5G networks will be Digital Radio over Fibre (DRoF) networks for deploying cloud radio access networks (CRAN). As conventional electronic data converters in DRoF networks suffer from jitter at very high giga sampling rates while photonic data converters have better performance, photonic data converters are considered a fundamental building block of a DRoF system for 5G. All Photonic Digital Radio over Fibre (AP-DRoF) is a suitable candidate for carrying future 5G data traffic from a central station for delivery to remote pico-cells. In this paper an 8-Bit binary-weighted Photonic Digital to Analogue Converter (PDAC) for AP-DRoF is proposed for the conversion of an optical bit stream generated by a Photonic Analogue-to-Digital Converter (PADC) into optical analogue signal for delivery to the photo diode of a remote station’s photonic antenna. The potential performance of the proposed PDAC is investigated at a sampling rate of 60 GigaSample/sec through simulation in terms of its Effective Number of Bits (ENOB) and Spurious Free Dynamic Range (SFDR)

SYLOS lasers – the frontier of few-cycle, multi-TW, kHz lasers for ultrafast applications at extreme light infrastructure attosecond light pulse source

The extreme light infrastructure attosecond light pulse source offers beamtime for users of various attosecond and particle sources driven by versatile laser systems. Here we report on the state of the art of a few-cycle, multi-TW, 1kHz repetition rate laser system, now fully operational in the facility. The system is based on four stages of optical parametric amplifiers (OPAs) pumped by a total of 320mJ, 80ps frequency-doubled Nd:YAG laser pulses. All OPA stages utilize double crystal configuration, which design has been also confirmed by model calculations. The 1kHz SYLOS 2 system produces 32mJ laser pulses around a central wavelength of 891nm with 6.6fs (<2.3 optical cycles) pulse duration exceeding the peak power of 4.8 TW on a daily basis. The recorded best pulse duration is 6.3fs, which corresponds to 2.12 cycles and 5.1 TW peak power. During long-term (24h) performance tests, energy stability of 1.2%, carrier-envelope phase (CEP) stability of 210mrad, and pointing stability of 0.4 mu rad were demonstrated, while the Strehl ratio of the beam is kept above 0.75. In order to help the alignment of all the different experiments at the facility and to reduce the workload on SYLOS 2 system, a second laser system has been developed. The so-called SYLOS Experimental Alignment (SEA) laser mimicks the performance of the SYLOS 2 laser, but at a repetition rate two orders of magnitude lower and without CEP-stabilization. The three single-crystal OPA stages of the SEA laser provide 42mJ pulse energy for the users, while having energy stability of 0.87% and sub-13fs pulse duration at a repetition rate ranging from a single shot up to 10Hz