Power scaling of blue and red light based on frequency mixing inside adhesive-free bond composite Nd:YAG laser cavity

We report our results on effective third-harmonic generation (THG) by cascading quasi-phase-matched second-harmonic and sum-frequency generation in a dual-period-periodically-poled KTP crystal. Significant improvement of the output powers were achieved for the 440 nm blue light and 660 nm red light based on Q-switched frequency-tripling and frequency-doubling 1319-nm radiation inside an adhesive-free bond composite Nd:YAG laser. The highest output powers of 197 mW and 1.19 W were achieved for the blue and red light at the corresponding input powers of 12.9 and 17.1 W for the diode laser.     

Experimental observation of superradiance in the stimulated scattering of an intense microwave pump wave by a counterpropagating subnanosecond high-current relativistic electron bunch

The generation of ultrashort superradiant pulses in the stimulated scattering of an intense microwave (38 GHz) pump wave by a counterpropagating high-current relativistic electron bunch has been observed. Scattered radiation is a single ～200-ps pulse with a peak power of about 1 MW. Owing to the Doppler shift of the radiation frequency, frequencies up to 150 GHz are present in the spectrum of the scattered pulse.     

The contribution of bends and constrictions of a superconducting film to the photon detection by a single-photon superconducting detector

The contribution of bends and constrictions by a superconducting film to the detection by a singlephoton superconducting detector is investigated. It has been shown that, for currents smaller than the minimal detection current of a straight film, the detection efficiency of a film with a constriction attains saturation upon an increase in the current, which coincides qualitatively with the behavior of this dependence observed in the experiment. It has also been found that the effect of bends in the film and the external magnetic field on the detection efficiency for low-energy photons is essential, while for high-energy photons no such influence is observed.     

New synthesis of bicyclo[1.1.0]butane hydrocarbons

Conclusions A new general synthesis is proposed for bicyclo[1.1.0]butanes, by 1,3-cyclization of 1-bromo-chloromethylcyclopropanes, and a two-step synthesis of the latter from available allyl chlorides has been developed.Deceased.Translated from Izvestlya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2043–2047, September, 1985.