Laser-induced self-phase modulation in polymeric films

Ultrafast laser-induced phase transitions in amorphous GeSb films.

Time-resolved measurements of the spectral dielectric function reveal new information about ultrafast phase transitions induced by femtosecond laser pulses in Sb-rich amorphous GeSb films. The excitation generates a nonthermal phase within 200 fs. The dielectric function of this phase differs from that of the crystalline phase, contrary to previous suggestions of a disorder-to-order transition....

Laser induced phase transition in iron thin films

Ytterbium gain band self-induced modulation instability laser.

We demonstrate an ytterbium gain band self-induced modulation instability laser. A highly nonlinear holey fiber is used to provide the anomalous dispersion required for bright soliton generation at 1 microm. The all-fiber integrated source yields a 40 GHz train of 4 ps pulses at a wavelength of 1064 nm.

Absorptionless self-phase-modulation via dark-state electromagnetically induced transparency

The closely related phenomena of dark states and electromagnetically induced transparency ~EIT! have greatly enriched the fields of nonlinear and quantum optics in recent years. Although these two processes produce similar effects, they have important distinctions. Atomic dark states @1,2# are coherent superpositions of the two lower levels in a threelevel lambda (L) system that are not coupled...

Irradiation induced electrical conductivity in polymeric thin films

Scientific objectives of this project are: (1) To produce and characterise uniaxially charge conducting ion tracks in thin polymeric films with high energy ion beam irradiation. (2) To understand the charge transport mechanisms within and as well as across ion tracks, which have been identified and shown to occur via electron transport across the carbon clusters that were formed within these io...