Author Affiliations
1Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication, Shanghai Institute for Advanced Communication and Data Science, Shanghai University, Shanghai 200444, China2School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200072, Chinashow less
Fig. 1. Experimental setup used to excite OVB pulse. WDM, wavelength division multiplexing coupler; EDF, erbium-doped fiber; PC, polarization controller; OSA, optical spectrum analyzer; CCD, charge-coupled infrared camera; PMF, polarization-maintaining fiber.
Fig. 2. Microscopy image of (a) the fabricated MKR and (b) the overlapping region.
Fig. 3. Spectral response of MKR: (a) Transmission spectrum with different incident states of polarization (SOP); (b) transmission spectra from 1553 nm to 1557 nm; and (c) polarization-dependent loss of the MKR.
Fig. 4. Simulation results: (a) Coupling efficiency as a function of the wavelengths; and (b) power exchange in the coupling region when LP01 mode in SMF converts to LP11 mode in FMF.
Fig. 5. Output near-field intensity distribution from a mode selective coupler by inputting a femtosecond pulse. (a), (e) Intensity profiles of the LP11 and LP21 modes; (b), (f) donut-shaped OAM mode patterns when pressing the output FMF; (c) and (d), and (g) and (h) corresponding clockwise and anticlockwise spiral interferograms of OAM±1 and OAM±2, respectively.
Fig. 6. Output spectra of successively tunable (a) single-, (b) dual-, (c) triple-, and (d) quadruple-wavelength lasing operations.
Fig. 7. Stability of triple-wavelength output spectrum. (a) Repeat scans of triple-wavelength output spectrum every minute. (b) Power fluctuation (black) and central wavelength (blue) of each channel in the triple-wavelength output every minute.
Fig. 8. Near-field distribution of LP11 intensities, OAM patterns, spiral interferograms, and the out spectra of wavelength-switchable laser. Four columns present (a)–(e) single-, (f)–(j) dual-, (k)–(o) triple-, and (p)–(t) quadruple-wavelength lasing operations. First row, LP11 intensity profiles; second row, donut-shaped mode patterns of vortex beams; third and fourth rows, corresponding clockwise and anticlockwise spiral interferograms; and fifth row, the output spectra.