Ultrashort pulsed laser micromachining/submicromachining using an acoustooptic scanning device with dispersion compensation

A precision laser-scanning apparatus, comprising:

• a laser source that emits a pulsed laser beam;
• a dispersion compensation scanner that scans the pulsed laser beam;
• and
• a focusing unit that focuses the pulsed laser beam from the dispersion compensation scanner onto a work piece, wherein the dispersion compensation scanner comprises
• a first scanning device that scans the pulsed laser beam in a first direction and that causes dispersion of the pulsed laser beam, and
• a first dispersion compensation device that compensates for the dispersion caused by the first scanning device;
• wherein the scanning random access time of the dispersion compensation scanner is in a range of approximately 1 nanoseconds to 100 microseconds.

A method of scanning a pulsed laser beam on a work piece for machining or cleaning the work piece, comprising:

• emitting a pulsed laser beam from a laser source;
• focusing the pulsed laser beam on the work piece;
• scanning the pulsed laser beam on the work piece using a first acoustooptical scanning device that scans the pulsed laser beam in a first direction and that causes dispersion of the pulsed laser beam;
• and
• compensating for the dispersion caused by the first scanning device using a first dispersion compensation device.

A method of scanning a pulsed laser beam on a work piece for machining or cleaning the work piece, comprising:

• emitting a pulsed laser beam from a laser source;
• focusing the pulsed laser beam on the work piece;
• converting a polarization of the pulsed laser beam to a predetermined polarization state prior to scanning the pulsed laser beam on the work piece;
• scanning the pulsed laser beam on the work piece using a first scanning device that scans the pulsed laser beam in a first direction and that causes dispersion of the pulsed laser beam;
• compensating for the dispersion caused by the first scanning device using a first dispersion compensation device;
• and
• machining a surface of the work piece by ablating material from the surface.

A method of scanning a pulsed laser beam on a work piece for machining or cleaning the work piece, comprising:

• emitting a pulsed laser beam from a laser source;
• focusing the pulsed laser beam on the work piece;
• scanning the pulsed laser beam on the work piece using a first scanning device that scans the pulsed laser beam in a first direction and that causes dispersion of the pulsed laser beam;
• compensating for the dispersion caused by the first scanning device using a first dispersion compensation device;
• scanning the pulsed laser beam in a second direction different from the first direction using a second scanning device that causes dispersion of the pulsed laser beam;
• and
• compensating for dispersion caused by both the first scanning device and the second scanning device using the first dispersion compensation device.

A precision laser-scanning apparatus, comprising:

• a laser source that emits a pulsed laser beam;
• a beam filter that spatially filters the pulsed laser beam and provides the pulsed laser beam with a desired cross-sectional size;
• wherein the beam filter includes a pin hole with a diameter approximately equal to or greater than a desired spot size of the pulsed laser beam when focused onto the work piece;
• a first focusing lens that focuses the pulsed laser beam onto the pin hole;
• a second focusing lens that collimates the pulsed laser beam emanating from the pin hole;
• and a diaphragm that blocks an outer portion of the pulsed laser beam emanating from the second focusing lens;
• a dispersion compensation scanner that scans the pulsed laser beam, wherein the dispersion compensation scanner comprises a first scanning device that scans the pulsed laser beam in a first direction and that causes dispersion of the pulsed laser beam, and a first dispersion compensation device that compensates for the dispersion caused by the first scanning device;
• a focusing unit that focuses the pulsed laser beam from the dispersion compensation scanner onto a work piece;
• and
• a polarization converter that provides a polarization state to the pulsed laser beam;
• wherein a pulse energy and an intensity of the pulsed laser beam are sufficient to machine a surface of work piece.