We present a critical review of the nonlinear optical responses of nematic liquid crystals associated with short pulsed laser induced thermal, density and order parameter fluctuations. Experimental studies conducted with absorbing as well as transparent nematic liquid crystals have demonstrated that all-optical one-way switching of nanoseconds pulsed laser at 750nm can be realized at sub-microseconds to nanoseconds speed. Similar switching performances have also been observed with lasers at other visible-infrared regime, confirming the broadband applicability of the underlying nonlinear optical processes.