We experimentally analyze the dynamics of a quantum dot semiconductor laser operating under optical injection. We observe the appearance of single- and double-pulse excitability at one boundary of the locking region. Theoretical considerations show that these pulses are related to a saddle-node bifurcation on a limit cycle as in the Adler equation. The double pulses are related to a period-doubling bifurcation and occur on the same homoclinic curve as the single pulses.

We have analyzed theoretically and experimentally the linewidth of the first harmonic of the photocurrent (radio-frequency (RF) linewidth) in monolithic passively mode-locked semiconductor lasers. Due to the absence of restoring force, the timing jitter is directly related to the RF linewidth, avoiding possible underestimations made with conventional methods of phase noise measurement. The RF linewidth is also analytically related to the pulse characteristics using Haus's model. The timing stability performance of a promising two-section quantum-dot laser is presented using RF linewidth measurements. Experimental evolution of the RF linewidth with power and pulsewidth is finally compared to the analytical expression.

We establish rate equations to describe Auger carrier capture kinetics in quantum dot structures, calculate Auger capture coefficients for self-assembled quantum dots, and analyze Auger capture kinetics using these equations. We show that Auger capture times can be of the order of 1–100 ps depending on barrier carrier and dot densities. Auger capture rates depend strongly on dot diameters and are greatest at dot diameters of about 10–20 nm.

We experimentally investigate pattern formation in a single-wavelength long laser cavity with a large Fresnel number. Near the laser threshold, we observe a single frequency spatially periodic structure corresponding to titled waves theoretically predicted by the Maxwell-Bloch equations. We also show the presence of secondary instabilities at other wavelengths and polarization instabilities at the same wavelength for different parameter values.

Using ultraviolet femtosecond pulses with high irradiance stability, we measured the two-photon absorption (TPA) coefficients in a number of substances with a total accuracy of ∼10%. Six commercial fused-silica samples (KU-1, Corning 7940, SQ, Suprasil, Herasil, and Infrasil) possess TPA coefficients (β values) of ∼2 × 10^-11 cm/W. For crystalline quartz and sapphire, the following β values were obtained: (1.2 ± 0.2) × 10^-11 and (9.4 ± 1.2) × 10^-11 cm/W, respectively. In β-barium borate crystal the TPA coefficient depends on crystal cut, beam polarization, or both and varies from (47 ± 5) × 10^-11 to (68 ± 6) × 10^-11 cm/W. For eight liquids that were studied (water, heavy water, ethanol, methanol, hexane, cyclohexane, 1,2-dichloroethane, and chloroform) the β value lies from (34 ± 3) × 10^-11 to (95 ± 11) × 10^-11 cm/W.