Fig. 5: Measured and simulated spectral distribution of the power transmission of the fundamental core mode of the fiber-coupled HCW.
Experimental transmission spectra of HCW when exposed to (a) air or (b) water. The vertical grey dashed line indicates the operating wavelength for the NTA experiments (λNTA = 532 nm). The insets show the corresponding spatial intensity distribution at λ0 = 525 nm (x-polarization). The bottom plots (c, d) show the simulated fundamental mode attenuation distributions in air and water, respectively, with insets showing the simulated mode at λ0 (scale bar is 4 μm). In all plots, the dark cyan and purple curves represent the fundamental modes being polarized with the electric field in y- or x-direction, respectively. The vertical green dashed lines indicate the resonance wavelength calculated by Eq. 1
