A laser shock peening apparatus includes a laser unit for generating at least
one
laser beam aimed at a laser shock peening area and an anti-feedback means for preventing
electromagnetic radiation reflections from the target area from entering the laser
unit during laser shock peening and the anti-feedback means is located between
the laser unit and a final focusing lens. The anti-feedback means may include an
optical isolator at an output of the laser unit such as a faraday isolator. Alternative
optical isolators may include thin film polarizers, glan prism polarizers, independent
pig tailed optical isolators, mirrors with enhanced P or S polarization coatings.
The laser unit may include an oscillator and a final amplifier and the output of
the laser unit located after the final amplifier.
