Slots with a width of about 25 μm is fabricated on Si (100) using a homebuilt micromachining system based on a 355 nm nanosecond pulse laser. Strong photoluminescence (PL) emission from the fabricated area is characterized by fluorescence microscopy and local fluorescence spectroscopy. Fluorescence emission in the wavelength range of 400-700 nm is detected with excitation wavelength range of 400-440 nm. Furthermore,a strong decay of the PL intensity is observed as a function of irradiation time. It can be confirmed that the optical property of silicon is changed after nanosecond pulsed laser fabrication. And a potential method to produce optoelectronic device based on silicon is tried with pulsed laser fabrication.