Short pulse processing and measurement

Original techniques for measuring the electric field of ultrashort light pulses have been developed and patented . They are based on time gated spectral shearing interferometry and provide direct recovery of the pulse amplitude and phase. They permit self-referenced sensitive measurement of repetitive pulses or in single shot.

Optical generation and processing of microwaves

Photonics technologies such as short pulses lasers, optical fibres and associated components, provide efficient tools to interact with very high frequency electrical signals. We develop photonics-based source of UWB electrical pulses together with signal processing methods leading to the realization of highly tunable and reconfigurable bandpass filters, leading to optical sampler for analog-to-digital converters and to optoelectronics arrayed antennas in the tens and more GHz frequency domains.

Spectral broadening in optical fibres for OCDMA

Code division multiplexing is a challenging and attractive technological solution for the future generation of high bit rate all-optical access networks. Nonlinear spectral broadening in fibers can be a promising technique of cost effective sources either with time or spectral encoding. We are currently studying the coherence problem of c-band infrared continuum generation to obtain undistored short pulses suitable for CDMA. These sources are currently developped from air-silica microstructured fibers with special dispersion profiles.

Three-wave solitons (in collaboration with University of Brescia- NORA group)

It has been theoretically demonstrated that parametric three wave interaction leads to a large variety of behaviours and permits the generation of solitary waves, the generation of pulse trains starting from a CW wave, the control of pulse speed, etc?We are carrying out experiments to demonstrate the predicted phenomena. Spontaneous transition from frequency generation to soliton regime have been observed for the first time.