Tunable comb-filter using thermally expanded core fiber and ytterbium doped fiber and its application to multi-wavelength fiber laser

• Published in: Optics communications Vol. 281; no. 23; pp. 5793 - 5796
• Main Authors: Nguyen, Linh Viet, Hwang, Du-sun, Moon, Dae Seung, Chung, Youngjoo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2008; Elsevier
• Subjects: Comb-filter; Exact sciences and technology; Fiber lasers; Filters, zone plates, and polarizers; Fundamental areas of phenomenology (including applications); Lasers; Multi-wavelength fiber laser; Optical elements, devices, and systems; Optics; Physics; Pump-induced index change; Semiconductor lasers; laser diodes; Thermally expanded core fiber; Ytterbium doped fiber; Thermally expanded core fiber; Multi-wavelength fiber laser; Ytterbium doped fiber; Pump-induced index change; Comb-filter; Optical filters; Interference fringe; Doped materials; Cladding mode; Comb filters; Laser diodes; Mach-Zehnder interferometers; Semiconductor lasers; Ytterbium additions; Tunable filter; Multifrequency laser; Ring lasers; Fiber lasers
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2008.08.033

We constructed a novel tunable comb-filter by splicing a commercial Yb 3+ doped fiber (YDF) between 2 thermally expanded core (TEC) fibers at their core-expanded ends. This structure forms an all-fiber Mach–Zehnder interferometer due to the interference between the core mode and the cladding modes of the YDF. The interference fringes shifts to the longer wavelength region as the YDF is pumped by a 980 nm laser diode (LD). We then demonstrated application of this newly proposed tunable comb-filter to a SOA-based ring laser and obtained multi-wavelength lasing. The lasing wavelengths can be also tuned by pumping the YDF in the proposed comb-filter.