RESUMO
A new method concerning secure free-space communications by means of chirped laser pulse interference is proposed. Physical-layer security of the link is ensured by encoding the data in a relative phase difference between two spatially separated beams. The possible architecture of the dual-node link is discussed based on acousto-optic elements for signal modulation and detection.
RESUMO
200 TW peak power has been achieved experimentally using a Cr:forsterite master oscillator at 1250 nm, a stretcher, three optical parametrical amplifiers based on KD*P (DKDP) crystals providing 14.5 J energy in the chirped pulse at 910 nm central wavelength, and a vacuum compressor. The final parametrical amplifier and the compressor are described in detail. Scaling of such architecture to multipetawatt power is discussed.
RESUMO
The purpose of the experiment was to study general and local effects of space flight factors on the rhythm of cellular activity and on the morphological and genetic properties of biological objects. The Pushchino strain, Actinomyces levoris Kras 17-225A-IBFM, isolated at the Institute of Biological Physics, Moscow, was chosen as the main biological object. Under appropriate conditions it gives distinct and continuous rings of spore formation reflecting its intrinsic high degree of synchronism in changing its reproduction forms seen with the unaided eye as transparent rings (vegetative growth) alternate with convex white rings (spore-formation growth). As an additional test object, a film culture of bacteriophage T4Br+ developed at the institute was used. The strains were placed together in one bioblock together with plastic detectors for detecting nuclear particles. The film culture of bacteriophage enabled us to amplify the area of registration of local radiation effects by studying the genetic effects of these: frequency of mutations, induced radiation, their spectrum, subsequent revertability under the action of chemical mutagens with known mechanisms of action on DNA molecules.
