title: Tunable-diode-laser measurements of gain in optically pumped NH(3).
abstract: A tunable-diode laser is used for the first reported time to make gain measurements in a cw optically pumped 12-microm NH(3) amplifier. The tunability of the diode laser enables us to demonstrate that no inversion exists in the 12-microm laser and that Raman processes are responsible for the gain. High-sensitivity techniques allow gain coefficients as low as 0.001%/cm to be detected, and the experimental measurements are found to be in good agreement with theory.
authors.forename: C
authors.initials: C
authors.lastname: Rolland
authors.forename: J
authors.initials: J
authors.lastname: Reid
authors.forename: B K
authors.initials: BK
authors.lastname: Garside
authors.forename: P E
authors.initials: PE
authors.lastname: Jessop
authors.forename: H D
authors.initials: HD
authors.lastname: Morrison