2.1.1. Ultraviolet lasers The ultraviolet laser systems used in the experiments described in Chapter 3 and listed in Table 3.1, covered a broad range of wavelengths and pulse durations. They included a seeded single-mode Nd:YAG laser, a nitrogen laser, and a Ti:sapphire ultrafast laser system. Nanosecond-duration pulses at 266 nm were generated using non-linear crystals to frequencyquadruple th...

Laser-based spectroscopic techniques have become firmly established in modern physical chemistry research because they are powerful tools for the study of atomic and molecular structure and dynamics. For example, a 1992 survey of experimental articles in issues of the Journal of Physical Chemistry and the Journal of Chemical Physics found that some 40% used lasers in some way (1). Until recentl...

We directly measure the nonlinear optical response in argon and nitrogen in a thin gas target to laser intensities near the ionization threshold. No instantaneous negative nonlinear refractive index is observed, nor is saturation, in contrast with a previous measurement [Opt. Express 17, 13429 (2009)] and calculations [Phys. Rev. Lett. 106, 183902 (2011)]. In addition, we are able to cleanly se...

The laser power density and its time history from a pulsed molecular nitrogen laser are calculated. Their dependence on the fill pressure and on various parameters of an electric circuit, in which the nitrogen gas acts as a variable resistor, is illustrated. It is shown that the peak power density increases in a circuit with low inductance and high capacitor voltage and that the energy density ...

Long bubble tracks, <1 mm in diameter, have been produced in liquid argon and nitrogen with a nitrogen laser beam (h = 337 nm), offering subnanosecond pulses with small beam divergence. Bubble formation was observed over a wide range of operating conditions, including those for ordinary bubble chamber operation, with a laser pulse of 10 #J. Typical bubble densities obtained were 4-8 bubbles/cm,...

background and objective: genital warts, due to specific types of the human papillomavirus, have long been regarded as one of the most important causes of cervical cancer and one of the most common cause of sexually transmited diseases (stds).  over the years, it has been the focus of several studies in order to find the best effective approach to eradicate the virus, however there are still co...

Femtosecond (fs)-laser hyperdoped silicon has aroused great interest for applications in infrared photodetectors due to its special properties. Crystallinity and optical absorption influenced by co-hyperdoped nitrogen in surface microstructured silicon, prepared by fs-laser irradiation in gas mixture of SF₆/NF₃ and SF₆/N₂ were investigated. In both gas mixtures, nitrogen and sulfur were incorpo...

The photophysical properties such as singlet absorption, molar absorptivity, fluorescence spectra, dipole moment, fluorescence quantum yields, fluorescence lifetimes and laser activity of 1,4-bis (β-Pyridyl-2Vinyl) Benzene (P2VB), 2,5-distyryl-pyrazine (DSP) and 1,4-bis(2-methylstyryl)benzene(MSB) diolefineic laser dyes have been measured in different restricted hosts. (P2VB), (DSP) and (MSB) a...

The current state-of-the-art in nanotip synthesis relies on techniques that utilize elaborate precursor chemicals, catalysts, or vacuum conditions, and any combination thereof. To realize their ultimate potential, synthesized nanotips require simpler fabrication techniques that allow for control over their final nano-morphology. We present a unique, dry, catalyst-free, and ambient condition met...