title: Saturated absorption spectroscopy of acetylene gas inside large-core photonic bandgap fiber.
abstract: Saturated absorption spectroscopy is performed on the acetylene nu(1) + nu(3) band near 1532 nm inside photonic bandgap fibers of small (approximately 10 microm) and large (approximately 20 microm) core diameters. The observed linewidths are narrower in the 20 microm fiber and vary from 20 to 40 MHz depending on pressure and power. Variations in the background light transmission, attributed by others to surface modes, are significantly reduced in the 20 microm fiber. The optimum signal for use as a frequency reference in a 0.8 m long, 20 microm diameter fiber is found to occur at about 0.5 torr for 30 mW of pump power. The saturation power is found by modeling the propagation and attenuation of light inside the fiber.
authors.affiliation: Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, KS 66506, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Thapa
authors.forename: Kevin
authors.initials: K
authors.lastname: Knabe
authors.forename: Mohammed
authors.initials: M
authors.lastname: Faheem
authors.forename: Ahmer
authors.initials: A
authors.lastname: Naweed
authors.forename: Oliver L
authors.initials: OL
authors.lastname: Weaver
authors.forename: Kristan L
authors.initials: KL
authors.lastname: Corwin