Highly focused Q-switched Nd:VDG fundamental (1.05 micron wavelength IR) and second harmonic (0.53 micron wavelencth green) laser pulses have been shonm to produce bulk defects in single crystal silicon at peak power densities below the vaporization threshold for the IR and below the melting threshold for the green. The defects decrease the encess rinoritv carrier lifetime as measured by junction leakage, junction step recovery, the MOS CV method, bioolar transistor current qain, and pn junction photocurrent. Green pulses have no effect on the thermal oxide dielectric strength or pn junction breakdown voltage at power densities up to the melting threshold. IR pulses begin to lower the junction breakdown voltage below the vaporization threshold and oxide dielectric strength is drastically lowered at or slightly below this threshold. The defect density decreases exponentially into the crystal with effective ranges of 0.7 micron and 1.7 microns for the green and IR respectively. IR absorption is very nonlinear near the vaporization peak power density threshold. The defects are a point type; are unchanged by a subsequent 400°C anneal; and are completely removed by an 800°C anneal. The results suggest some detrimental effects of laser processing of silicon intergrated circuits as well as some new potential applications.