  In this paper, we propose a liquid core suspended photonic crystal fiber
(LCSPCF) as a potential waveguide structure for nonlinear applications. We
emphasize the dramatic improvement of the nonlinear properties of the PCF
through the infiltration of liquid and highlight the effect of suspension in
the further enhancement of nonlinearity. To demonstrate the capability of
LCSPCF, we perform a modulation instability (MI) study and illustrate the MI
enhancement in the LCSPCF against conventional PCF. As the LCSPCF possesses
high nonlinearity, it is important to consider the effects of higher-order
nonlinearities. We observe that the quintic nonlinearity (QN) increases the MI
for cooperating nonlinearities while it suppresses the MI for competing
nonlinearities. We have also importantly studied the effect of QN on the MI
induced supercontinuum generation (SCG) for silica and CS2 liquid core PCF.
Thus, we propose the LCSPCF as a platform for nonlinear applications such as
SCG, pulse compression, etc., owing to the presence of high and controllable
nonlinear coefficients.
