title: Note: Longitudinally excited N₂ laser with low beam divergence.
abstract: We developed a longitudinally excited N2 laser (337 nm) with low beam divergence without collimator lenses. The N2 laser consisted of a 30 cm long Pyrex glass tube with an inner diameter of 2.5 mm, a normal stable resonator formed by flat mirrors, and a simple, novel driver circuit. At a N2 gas pressure of 0.4 kPa and a repetition rate of 40 Hz, the N2 laser produced a circular beam with an output energy of 2.6 μJ and a low full-angle beam divergence of 0.29 mrad due to the uniform discharge formed by the longitudinal excitation scheme, the long cavity with the small aperture, and the low-input energy oscillation.
authors.affiliation: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Uno
authors.affiliation: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Akitsu
authors.affiliation: Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Jitsuno