Submicrosecond regular and chaotic nonlinear dynamics in a pulsed picosecond Nd:YAG laser with millisecond pumping.

We propose and study both numerically and experimentally a feedback-controlled laser system capable of generating regular bursts with a submicrosecond period. Bursting is obtained in a laser that is controlled by a combination of feedbacks in which the negative feedback loop action is delayed by one cavity round trip with respect to the positive one, and the period is adjusted by relative feedback sensitivity. The proper combination of feedbacks is realized in a Nd:YAG laser with millisecond pumping by means of a single optoelectronic negative feedback unit that utilizes the signal reflected from an intracavity Pockels cell polarizer.

Manifestation of active medium astigmatism at transverse mode locking in a diode end-pumped stable resonator laser.

Transverse mode locking in a diode end-pumped Nd:YAG laser with up to approximately 140 cm resonator length was investigated. It was found that for each resonator degeneracy, there are two degenerate lengths where the fundamental mode is very different from the Gaussian mode. Fundamental mode intensity patterns for these lengths expand in directions perpendicular to each other.

Optical pulse distance-multiplying interferometry.

A possibility of creation of long baselines by the distance-multiplying interferometric method for a calibration distance-measuring apparatus is considered. In contrast to existing versions of this method, in which cw radiation is used, we propose using wideband picosecond continuum radiation generated by powerful ultrashort laser pulses. In the experiment the interference pattern that is typical for white light, with a stable achromatic fringe, was observed.