title: Closely spaced dual-wavelength fiber laser using an ultranarrow bandwidth optical filter for low radio frequency generation.
abstract: A dual-wavelength (DW) fiber laser with a closely spaced single longitudinal mode (SLM) output is proposed and demonstrated. The proposed fiber laser utilizes a conventional fiber Bragg grating with a center wavelength of about 1546.8 nm in conjunction with an ultranarrow bandwidth tunable optical filter to generate the desired DW SLM output. Observations with a very high resolution optical spectrum analyzer, which was capable of achieving resolutions up to 0.16 pm, revealed detailed spectral characteristics not characteristically seen before. A channel spacing of up to 58 nm was realized, and spacing as small as 2 pm was achieved. The minimum channel spacing and its resulting beat frequency are the narrowest observed yet to the best of our knowledge for a DW fiber laser at room temperature.
authors.forename: H
authors.initials: H
authors.lastname: Ahmad
authors.forename: N F
authors.initials: NF
authors.lastname: Razak
authors.forename: M Z
authors.initials: MZ
authors.lastname: Zulkifli
authors.forename: F D
authors.initials: FD
authors.lastname: Muhammad
authors.forename: Y
authors.initials: Y
authors.lastname: Munajat
authors.forename: S W
authors.initials: SW
authors.lastname: Harun