Para-quaterphenyl vapor laser with a quantum efficiency of 20%

Measurements were made of the quantum efficiency (at λ = 352±10 nm) of a laser utilizing paraquaterphenyl vapor mixed with pentane. The density of the buffer gas (pentane) molecules was 1.5×10²¹ cm^–3 (at T=210 °C). Studies were made using various resonators. The vapor mixture was excited by the fourth harmonic (266 nm) of a neodymium laser in a transverse geometry. Efficient lasing of para-quaterphenyl vapor was observed as a result of hard ultraviolet pumping.