All-fiber comb filter with tunable free spectral range.
We demonstrate a new class of all-fiber frequency comb filter that exhibits unprecedented capabilities for tuning the comb's free spectral range (FSR). The filter exploits a spectral Talbot-like effect in a sampled chirped fiber Bragg grating. The FSR is tailored by application of a linear strain gradient to modify the relative phase between the samples. The FSR can be tuned in discrete steps that correspond to the nominal value of the FSR of the sampled unchirped grating divided by integer factors. In this demonstration the FSR is varied from 51 to 3.9 GHz.
Magné
Julien
J
Centre d'Optique, Photonique et Laser, Université Laval, Quebec G1K 7P4, Canada.
Giaccari
Philippe
P
LaRochelle
Sophie
S
Azaña
José
J
Chen
Lawrence R
LR