Fig. 1. (a) Microscopic images of the MKR with a loop diameter of D≈480.6  μm, and the inset shows the waist region of the MF with a diameter of d≈7.0  μm. (b) Transmission of the MKR structure where the largest obtained ER is ∼18.0  dB at a resonance wavelength around 1542.3 nm.

Fig. 2. (a) Raman spectrum of the SnS2 nanosheets. (b) Absorption spectrum of the SnS2 nanosheets.

Fig. 3. (a) Microscopic image of the MKR coated with SnS2 nanosheets. (b) SEM image of the MKR coated with SnS2.

Fig. 4. Experimental setup for light amplitude tuning by violet pump light power.

Fig. 5. (a) Transmission recorded from the MKR without SnS2 (red curve) and the MKR with SnS2 (green curve). The purple ellipse shows one minor resonance in the MKR without SnS2. (b) Measured normalized transmission spectrum of the MKR without SnS2 (red curve) and the corresponding fitted resonance curve (black circles). The fitted curve is obtained by setting γ=0.033, κr=0.298, and Re(neff)=1.47.

Fig. 6. (a) Measured normalized transmission spectra of the MKR with SnS2 (green curve) and the corresponding fitted resonance curve (black circles). The fitted curve is obtained by setting γ=0.673, κr=0.217, and Re(neff)=1.42. (b) Transmission of the MKR structure at different external violet pump light powers. The red, black, brown, cyan, and blue curves correspond to the transmission with external violet pump power of 0, 5.1, 10, 15.3, and 20.2 mW, respectively.

Fig. 7. Transmission spectrum of the MKR with SnS2 under different violet pump power excitation within a wavelength range of (a) 1532 nm to 1545 nm, while the two modes highlighted with red ellipses are around 1533 nm and 1544.7 nm, and (b) 1563 nm to 1570 nm, while the two modes highlighted with red ellipses are around 1564 nm and 1569.6 nm.

Fig. 8. Linear fit of ΔT versus violet light power for four different resonances at λres=1533  nm (red curve with a correlation coefficient of 93.8%), λres=1544.7  nm (black curve with a correlation coefficient of 98.4%), λres=1564  nm (blue curve with a correlation coefficient of 98.4%), and λres=1569.6  nm (pink curve with a correlation coefficient of 99.5%).

Fig. 9. (a) Experimental setup for device response time measurement. (b) Response time of the device at a probe wavelength of 1548 nm with a violet light power of 2.3, 4.4, and 6.3 mW.