Fig. 1. (a) Experimental setup for the microresonator/ZBLAN-fiber hybrid system. Inset: photograph of the output light spot in our experiment. (b) Optical transmission spectrum of the fiber end-facet mirror M1. Insets: photograph (left) and microscopic image (right) of M1. (c) A microscopic image of the silica microsphere used in the experiment.

Fig. 2. Semi-quantitative relationship between Pthreshold[K(W)] and R2 using DBR M1 (R1=95.7%, blue solid line) or the FBG (R1=99%, red dashed line) as the input mirror.

Fig. 3. (a) Laser output spectrum under a pump power of ∼263  mW. Inset: detailed optical spectrum at ∼635  nm. (b) Fluorescence spectrum from the output port without a microsphere as the feedback element. Inset: a partial energy level diagram of Pr3+ ions in the ZBLAN fiber.

Fig. 4. (a)–(f) One- to six-order Raman Stokes laser spectra in the visible band under pump powers of 347, 359, 385, 446, 558, and 603 mW, respectively.

Fig. 5. Threshold power dependence on the Raman Stokes order. Blue dots: experimental data. Red dashed line: cubic fitting.

Fig. 6. (a) First-order Raman Stokes laser power versus pump power. Blue dots: experimental data. Red dashed line: square root fitting. (b) Second-order Raman Stokes laser power versus pump power. Blue dots: experimental data. Red dashed line: linear fitting.

Fig. 7. (a) Spectrum of a single-wavelength laser at 635.5 nm under a pump power of ∼280  mW, (b) the output power of the single-wavelength laser at ∼635.5  nm versus pump power, (c) Brillouin spectra under different pump powers.