Cairo University

MTPR Journal



Walid Tawfik
Environmental, Photochemistry and Agricultural Applications Department, National Institute of Laser NILES, Cairo University, Cairo, Egypt.
Vol./Issue: 16 , id: 192

Ultrafast laser pulses have beenvital for a varietyof developed applications like: X- ray free electron laser generation X-FEL, femtosecond laser pulses induced high harmonic generation and as an essential means for creation of ultraviolet coherent attosecond laser pulses [1]. Recently, high power table-top laserschemebasically depends on Ti:Sapphire as an amplifiermedium, and some terawatt-class laser systems have been established [2]. Nevertheless, these sophisticated systems have serious problems like pulse deformation due to thermal load on the amplifiers and thermal lensing particularly inside the laser rod [3]. In this work, generation and characterization of broadband-ultrafast high energy laser pulses have been considered using a relatively simple methodology. The characterization of ultrafast pulses in the regime of few-cycle pulses has been considered using spectral phase interferometry for direct electric-field reconstruction (SPIDER) [4]. These pulses were produced due to supercontinuum triggered by self – phase modification (SPM) in neon gas filled hollow-fiber followed by a set of chirpedmirrors for dispersion compensation. The generated output pulses after compression achieved ~ 5femtosecond pulse duration with high energy of sub-mJ at 1 KHz repetition rate. The output spectral bandwidth found to cover broadrange from 550 – 950 nm.It has been found that the out put pulse width is affected by thepulse duration of the injected femtosecond pulses into the optical fiber under different gas pressures. The obtained pulses may give a chance to create high harmonic generations HHGwhich could be used for generation of extremely short pulses down to x-ray regime with short pulse durations down to attosecond regime in future.