"A" cited "B".



"A":

S. Vargas, C. Vazquez, and J. M. S. Pena (Universidad Carlos III, Spain), "Novel tunable optical filter employing a fiber loop mirror for synthesis applications in WDM," IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting, San Diego, CA, USA, Nov. 2001, pp. 899-900.



"B":

S. Kim and B. Lee, "Recirculating fiber delay-line filters with a fiber Bragg grating," Applied Optics, vol. 37, no. 23, pp. 5469-5471, 1998.