title: Sensitive absorption spectroscopy with a room-temperature distributed-feedback quantum-cascade laser.
abstract: We report what we believe are the first spectroscopic measurements to be made with a room-temperature quantum-cascade distributed-feedback laser. Using wavelength modulation spectroscopy, we detected N(2)O and CH(4) in the chemical fingerprint wavelength range near 8microm . The noise equivalent absorbance for our measurement was 5 parts in 10(5), limited by excess amplitude modulation on the laser output, which corresponds to a 1-Hz bandwidth detection limit of 250 parts N(2)O in 10(9) parts N(2) in a 1-m path length.
authors: K
authors: K
authors: Namjou
authors: S
authors: S
authors: Cai
authors: E A
authors: EA
authors: Whittaker
authors: J
authors: J
authors: Faist
authors: C
authors: C
authors: Gmachl
authors: F
authors: F
authors: Capasso
authors: D L
authors: DL
authors: Sivco
authors: A Y
authors: AY
authors: Cho