In-fiber Mach-Zehnder interferometer based on a Nd-doped double-clad fiber for switchable single and dual-wavelength EDF laser application

• Published in: Laser physics 2017-05, Vol.27 (5), p.55102
• Main Authors: Castillo-Guzmán, A A, Álvarez-Tamayo, R I, Sierra-Hernández, J M, Salceda-Delgado, G, Selvas-Aguilar, R, Durán-Sánchez, M, Ibarra-Escamilla, B
• Format: Article
• Language: English
• Subjects: erbium-doped fiber; fiber design and fabrication; fiber lasers; wavelength filtering
• ISSN: 1054-660X; 1555-6611
• DOI: 10.1088/1555-6611/aa6851

We present an experimental study of a novel Mach-Zehnder in-fiber interferometer and its application for single and dual-wavelength operation of a ring cavity fiber laser. The proposed in-fiber interferometer, consisting of a segment of Nd-doped fiber spliced between two segments of standard single mode fibers, exhibits a wavelength periodical transmission spectrum with a period of 2.8 nm and a fringe contrast of ~0.8 dB. The Mach-Zehnder interferometer (MZI) is used as a spectral filter to obtain switchable single and dual-wavelength operation of an Er-doped fiber laser (EDFL). Laser emission with laser lines spectral width less than 0.22 nm and wavelength separation of 2.8 nm corresponding to transmission spectrum wavelength period of the MZI is obtained. The stability of the dual-wavelength operation of the EDFL is also discussed. The use of the proposed in-fiber MZI as a reliable, spectral filter to achieve stable single and dual-wavelength laser generation in a ring cavity fiber laser is experimentally demonstrated.