Ivan Kertesz

Influence of optical field emission on the nonlinear photoelectric effect induced by ultrashort laser pulses

Abstract A decrease in the order of nonlinearity of photoelectron emission from a metal cathode was found experimentally with mode-locked laser pulses at sufficiently high intensities. This phenomenon is interpreted as due to the theoretically predicted appearance of optical field emission.

Nonlinear photoelectric electron emission induced by picosecond mode-locked laser pulses

The emission of photoelectrons from metals and semiconductors irradiated with relatively long light pulses from free-running or giant-pulse lasers has been already studied by a number of authors (1.~). I t seemed of interest to investigate the effects produced by irradiation with modelocked laser pulses of picosecond duration and power density of the GW/em ~ order. The pulses of this type were expeoted to permit the following observations.

Piezoelectric Driven Devices for Periodical Q-switching of High Average Power Lasers

The most essential specific demand for a Q-switching device of a high average power continuously pumped laser operating at 1.06 μm is proper operation in a very high optical flux without overheating or any kind of damage.

Optoelectronic element for control of spatial and time behavior of medical lasers

The strong angular and base dependence of the Fabry-Perot interferometer reflectivity is used for the increase of beam quality and power of medical lasers. The smaller divergency makes the use of thinner (more bendable) optical fiber possible.

Pulsed solid state lasers for medicine

The effect on living tissues of different pulsed solid state lasers: Nd:YAG ((lambda) equals 1.06 micrometers ) Er:glass (1.54 micrometers ), Ho:YAG (2.1 micrometers ) and Er:YAG (2.94 micrometers ) is compared with the continuous wave Nd:YAG- and CO2-lasers used in operating theaters. Portable Er:glass- and Er:YAG-lasers are developed for surgery/cosmetics and HIV-safe blood testing.

Method For Compensation Of Thermal Lensing In Slab Lasers

The very efficient phosphate glasses of high Nd3+ concentration have relatively (compared to YAG) low thermooptical parameters. In the athermal glasses the thermomechanical stress leads to fraction at moderate average pumping already. Slab geometry with higher than 2.1 width to thickness ratio ensures higher fraction threshold than that of a cylindrical rod of the same cross section, but the thermal lensing causes high-pumping rate dependent-divergence. To compensate the lensing in a relatively wide pumping/repetition rate range a cylindrical resonator was used. With cylindrical mirrors the output beam stability was excellent.