title: 1.2W laser amplification at 1427nm on the4F3/2to4I13/2spectral line in an Nd3+doped fused silica optical fiber.
abstract: A 9.3dB improvement in optical gain and a 100x improvement in total optical power over prior published experimental results from the4F3/2to4I13/2transition in an Nd3+doped fused silica optical fiber is demonstrated. This is enabled via an optical fiber waveguide design that creates high spectral attenuation in the 1050-1120nm-wavelength range, a continuous spectral filter for the primary4F3/2to4I11/2optical transition. A maximum output power at 1427nm of 1.2W was attained for 43mW coupled seed laser power and 22.2W of coupled pump diode laser power at 880nm a net optical gain of 14.5dB. Reducing the coupled seed laser power to 2.5mW enabled the system to attain 19.3dB of gain for 16.5W of coupled pump power. Four issues limited results; non-optimal seed laser wavelength, amplified spontaneous emission on the4F3/2to4I9/2optical transition, low absorption of pump light from the cladding and high spectral attenuation in the 1350-1450nm range. Future fibers that mitigate these issues should lead to significant improvements in the efficiency of the laser amplifier, though the shorter wavelength region of the transition from 1310nm to >1350nm is still expected to be limited by excited state absorption.
authors.forename: Jay W
authors.initials: JW
authors.lastname: Dawson
authors.forename: Paul H
authors.initials: PH
authors.lastname: Pax
authors.forename: Graham S
authors.initials: GS
authors.lastname: Allen
authors.forename: Derrek R
authors.initials: DR
authors.lastname: Drachenberg
authors.forename: Victor V
authors.initials: VV
authors.lastname: Khitrov
authors.forename: Nick
authors.initials: N
authors.lastname: Schenkel
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Messerly