Resonant third harmonic generation of KrF laser in Ar gas.

Investigations of emission of harmonics from argon gas jet irradiated by 700 fs, 5 mJ pulses from a KrF laser are presented. Harmonics conversion was optimized by varying the experimental geometry and the nozzle size. For the collection of the harmonic radiation silicon and solar-blind diamond semiconductor detectors equipped with charge preamplifiers were applied. The possibility of using a single-crystal CVD diamond detector for separate measurement of the 3rd harmonic in the presence of a strong pumping radiation was explored. Our experiments show that the earlier suggested 0.7% conversion efficiency can really be obtained, but only in the case when phase matching is optimized with an elongated gas target length corresponding to the length of coherence.

[Letters from professor Benedykt Dybowski to Professor Jan Grochmalicki, his former student and my father]. / Listy profesora Benedykta Dybowskiego do jego wychowanka a mojego Ojca profesora Jana Grochmalickiego.

A valuable contribution to familiarization with the character of professor Benedykt Dybowski (1833-1930), a physician and zoologist, sentenced to exile in Traugutt's trial, explorer of Siberia and professor of Jan Kazimierz University in Lwów, can be made by a two preserved letters from professor Dybowski to Jan Grochmalicki (1883-1936), who was his former student and the closest co-worker enjoying his special confidence. The exchange of letters began in April 1919 at the moment of professor Grochmalicki's moving to Poznan where he became head of the Department of Zoology at the University of Poznan, which was just established, and professor Dybowski remained in besieged Lwów. In the last letter written in June 1929, ailing 97-years old professor Dybowski says his farewells in the words "I am going at a quick pace to Nirvana". The letters throw light both on the difficult time of the birth of the Second Republic of Poland and rich personality of Benedykt Dybowski.