BRIEF COMMUNICATIONS: Possibility of attainment of anomalously strong directionality of amplified spontaneous radiation
A study was made of the divergence of amplified spontaneous radiation from an extended source. An Ar–N2 mixture was excited by a high-intensity proton beam and it emitted ultraviolet radiation as a result of transitions in the second positive system of the N2 molecule. The pump power density reached 2.2×107Watm−1cm−3 and the length of the excited region was 30 cm. An anomalously strong directionality of amplified spontaneous radiation was observed: this directionality was 20 times higher than that expected on geometric grounds.