Cavity dumped laser shock peening process
AssigneeGeneral Electric Company
InventorsFarzin Homayoun Azad, Josef Robert Unternahrer
Life of this patent
Estimating the term…
Abstract
A laser shock peening apparatus includes a cavity dumping laser oscillator including in optical serial alignment a first mirror, a Pockels cell, a polarizer, a laser rod, and a second mirror defining a cavity having an optical length between the mirrors. The laser rod is optically pumped to generate a laser beam in the cavity, and the Pockels cell has selective wave retardation to allow the beam to oscillate between the mirrors and increase energy therein, followed in turn by dumping the beam into a laser amplifier. The laser amplifier directs the amplified pulse at a target for laser shock peening thereof. The cavity length is selected to develop a substantially square-wave laser pulse for temporally shaping the resulting pressure pulse at the target.
Claims17
A method for laser shock peening a target for developing residual compressive stress at a surface thereof, the method comprising the steps of:
- generating a laser beam pulse from a cavity dumping oscillator having a sharp leading edge by circulating a laser beam in said oscillator to pump energy in the laser beam to a peak, and switching a Pockels cell to change a degree of wave retardation of the laser beam to dump the laser beam out of the oscillator as the laser beam pulse;
- selecting a switching time of the Pockels cell to control the leading edge of the laser beam pulse;
- and
- directing said laser beam pulse against said target to develop a pressure pulse at the target for laser shock peening of the target, wherein the laser beam pulse is directed against the target without reducing a duration of the leading edge of the laser beam pulse.
A method of laser shock peening a target comprising the steps of:
- pumping energy into a laser rod;
- oscillating a coherent beam through the laser rod in an oscillator such that the coherent beam is amplified to a peak by the energy pumped into the laser rod;
- switching a Pockels cell to change a degree of wave retardation of the coherent beam and dump the coherent beam out of the oscillator as a laser pulse;
- selecting a switching time of the Pockels cell to control a rise time of the laser pulse;
- and
- directing the laser pulse against a target, wherein the laser pulse is directed against the target without reducing a duration of the rise time of the laser pulse.
Dependencies are inferred from the claim text.