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We report a method for producing, from the raw materials, high optical and geometrical quality glass tubes and photonic crystal fiber (PCF) preforms, without using extrusion or drilling at any stage. A thermal glass study was carried out in order to choose the appropriate glass composition to avoid crystallization problems during the tube, preform and fiber fabrication. A two period PCF was fabricated in addition to a co-doped Erbium and Thulium photonic crystal fiber. In the latter, a 187 nm wide amplified spontaneous emission (ASE) spectrum was obtained when pumping a 15 cm long fiber at a wavelength of 790 nm.

We present absorption spectra as a function of temperature for CdTe quantum dots in doped glasses. We calculate the absorption spectra considering the transition energies from a spherical model. We consider also the inhomogeneous broadening due to the quantum-dot size distribution and the homogeneous broadening, due mainly to electron-phonon interactions. The samples grown with a two-step heat treatment present very thin size distributions, with a standard deviation of 5.8%, which is comparable to the best CdSe samples in the literature. Also, the results show that the homogeneous width increases as the quantum-dot size decreases, indicating an enhancement of the electron-phonon interaction for small dots.

Electron-hole recombination in CdTe quantum dots was studied by photoluminescence and resonant femtosecond pump–probe measurements. A dependence of recombination times with pump pulse intensity was observed and we attribute this to the Auger recombination process. The overall kinetic processes that we observed are a fast decay from the initial excited state to surface trap states, the Auger recombination, the recombination of electrons from the surface states, and a longer time recombination which we attribute to electrons in the deep traps states.

Nonlinear interaction between spectral components in two different photonic bandgaps is experimentally demonstrated by launching femtosecond pulses near a zero-dispersion wavelength of a hybrid photonic crystal fiber, which guides by a combination of total internal reflection and bandgap effects. It is demonstrated that the initial pulse becomes spectrally broadened, and narrowband resonant radiation is generated in a different bandgap from the one responsible for guiding at the pump wavelength. The spectral intensity of the resonant radiation peaks at 2.7 dB below that of the broadened pulse in the pump-guiding bandgap.

This letter describes a principle demonstration of an ultrafast optical switch operating at 1Tbit∕s using CdTe-quantum-dots-doped glasses. Using a three-beam pump and probe experiment, we showed that thermal effects are responsible for a baseline in the pump and probe graphs and the nonexistence of carrier accumulation effects. After eliminating the thermal effects, we showed that, when two pump pulses are delayed by 1 ps, each pump pulse modulates the probe pulse independently, making this material highly promising for ultrafast all optical switching.

We use a rate equation model to analyse a technique for the generation of picosecond duration laser pulses in argon pumped dye lasers. The system is based on passive mode-locking of the Ar+ laser by saturable absorption of the dye which is inserted in the Ar+ laser cavity. Simultaneously, the dye is forced to oscillate in a regime of synchronously pumped mode-locking. The system is relatively simple, does not require the use of an acousto-optical light modulator and can be easily implemented in commercially available lasers. Pulses shorter than 100 ps and having an average power of 20 mW were obtained at a repetition rate of 110 MHz. Good agreement between the model and experimental results was also obtained.

A detailed analysis of a self-injected Nd: YAG laser with an unstable cavity is presented. With respect to the normal Q-switched laser-mode operation the pulse peak power is increased by a factor of eight with a pulse length of about 1 ns. Moreover single transverse mode operation is achieved, with divergence near the diffraction limit. An evaluation of the most significant parameters useful for the design of an unstable resonator for self-injection applications is also presented.

The efficiency, duration, and spectral content of the emission from laser‐produced Ta plasmas in the 10–71 nm spectral region have been measured for laser pulse durations ranging from 100 fs to 70 ps. Efficiencies from 0.3% for 100 fs pulses to 2.65% for 70 ps pulses, x‐ray pulse durations from less than 10 ps for 100 fs excitation pulses to 105 ps for 70 ps excitation pulses, and spectral content peaking in the 17–35 nm region were measured for 1 mJ pulses at intensities from 1011 to 5×1014 W/cm2.

We report the measurement of intervalley scattering rates for optically excited carriers in GaAs. The measurements were performed using optical pulses of 6 fs duration and an energy distribution centered at 2.0 eV. The average rates for Γ→X and Γ→L intervalley scattering were separately estimated by varying the sample temperature.

The first ’’self‐injected’’ unstable resonator laser is reported. 1‐ns, high peak power, single‐mode pulses are generated with neodymium‐yttrium aluminum garnet (Nd‐YAG) laser made with the same relevant optical components of the commercial DCR1 Quanta Ray oscillator.