title: Tunable wavelength division multiplexing channel isolation filter based on dual chirped long-period fiber gratings.
abstract: We propose and demonstrate a wavelength tunable wavelength division multiplexing channel isolation filter based on two concatenated chirped long-period fiber gratings (LPGs). An intergrating space (IGS), deliberately introduced between the two gratings, provides an extra phase difference between the core and cladding modes. Changing this phase by heating the IGS without affecting the gratings tunes the channels. A theoretical account of the filter action is also presented and the results are found to be in excellent agreement with the experiments. Unlike the filters based on normal concatenated chirped LPGs without an IGS, the current filter shows a linear tuning over an increased spectral range.
authors.affiliation: Central Scientific Instruments Organisation, CSIR-New Delhi, Sector 30, Chandigarh 160030, India.
authors.forename: Umesh
authors.initials: U
authors.lastname: Tiwari
authors.forename: Saurabh Mani
authors.initials: SM
authors.lastname: Tripathi
authors.forename: Krishna
authors.initials: K
authors.lastname: Thyagarajan
authors.forename: Mangalpady Raj
authors.initials: MR
authors.lastname: Shenoy
authors.forename: Vandana
authors.initials: V
authors.lastname: Mishra
authors.forename: Subhash Chander
authors.initials: SC
authors.lastname: Jain
authors.forename: Nahar
authors.initials: N
authors.lastname: Singh
authors.forename: Pawan
authors.initials: P
authors.lastname: Kapur