Design and analyses of compact bent‐tapered waveguides using guided‐wave lens sets

Abstract

produced, or the same thresholds for both modes can be obtained, which results in the third state.By using the tuning scheme to apply axial and lateral strain on the FBG, we can change the wavelengths of the dual-wavelength laser. Figure 3 shows the output spectrum of the EDFL when the axial strain is 818 (according to the translation stage's displacement of 0.1 mm) and the screw angle is 50°. The dual lasing wavelengths are 1554.44 and 1554.84 nm, respectively. Figure 4 shows the dependence of the wavelength spacing upon the lateral strain when the axial strain is zero and Figure 5 shows the wavelength shift with respect to the axial strain when the lateral strain is zero. Linear responses were observed in both figures. Considering the mechanical properties of glass fiber, the wavelength shift can not exceed ϳ 2 nm using the axial-strain tuning method. CONCLUSIONIn conclusion, we have demonstrated a tunable, stable dual-wavelength EDFL at room temperature with only a single-mode FBG applied with lateral strain. Adjusting a PC in the cavity allows us to achieve either single-or dual-wavelength laser outputs. Two lasing wavelengths of this simple and low-cost laser can be tuned continuously. ACKNOWLEDGMENTSThis work is supported by the Tianjin Natural Science Foundation project, multiwavelength optical fiber laser in DWDM communication systems, under grant no. 013601811, and the startup Foundation of Scientific Research provided by the Personnel Department of Nankai University, P.R. China. DESIGN AND ANALYSES OF COMPACT BENT-TAPERED WAVEGUIDES USING GUIDED-WAVE LENS SETS