We demonstrate a fast Quasi-Continuous frequency scanning semiconductor laser source for optical fiber sensor interrogation systems. The tunable laser covers a wavelength range of 32nm in C-band with tuning resolution of 8pm. The scanning time over the complete wavelength range in C band is less than 1ms while the switching time from one wavelength point to another point can be less than 100ns. A fast current driver controlled using FPGAs have been employed to drive a DSDBR laser for the realization of the fast tunable laser module. Experimental results have verified its possible application in optical sensor interrogation systems.