Laser ablation control system and method

In a process for laser ablation including the steps of:

• providing a laser for emitting a plurality of pulsed beams of controlled intensity from said laser for ablation of a work piece;
• holding a work piece having a known ablation threshold and rate of ablation above said threshold for incidence of said pulsed beams of controlled intensity to ablate a portion of said work piece;
• causing incidence of said pulsed beams of controlled intensity at said work piece from said laser to produce ablation of an opening of specific shape at said work piece;
• the improvement to said ablation process comprising the steps of:
• providing a laser beam sensing subsystem for diverting a fraction of said laser beam;
• analyzing said diverted beam in pointing, coherence, phase and irradiance profile;
• collimation and pointing said laser beam responsive to said laser beam sensing subsystem measured pointing, coherence, and phase;
• and,
• predicting the pulses of controlled intensity required to ablate said opening of specific shape at said work piece responsive to said coherence, phase, and irradiance profile of said laser beam through said means for incidence;
• and,
• pulsing said laser at said controlled intensity for ablating said opening of specific shape on said work piece.

A process of ablating a feature of preselected size and shape on a work piece of known material having an ablation threshold and known rates of ablation above said threshold having the steps of:

• providing a laser for emitting pulsed beams of controlled intensity for ablating said feature of preselected size and shape;
• providing a transparent substrate having image information for ablating said feature of preselected size and shape;
• providing means for scanning said beam over said transparent substrate across said image information for ablating said feature of preselected size and shape;
• providing means for controlling said scanning and pulsing;
• providing a laser beam sensing subsystem for diverting a fraction of said laser beam;
• analyzing said diverted beam in pointing, coherence, phase and irradiance profile;
• collimation and pointing said laser beam responsive to said laser beam sensing subsystem measured pointing, coherence, and phase;
• predicting the pulses of controlled intensity and scan required to ablate said opening of specific shape at said work piece responsive to said coherence, phase, and irradiance profile of said laser beam through said means for incidence;
• and,
• pulsing and scanning said laser to produce said opening of specific shape in said work piece.

In a process for laser ablation including the steps of:

• providing a laser for emitting a plurality of pulsed beams of known intensity from said laser for ablation of a work piece;
• holding a work piece having a known ablation threshold and rate of ablation above said threshold for incidence of said pulsed beams to ablate a portion of said work piece;
• causing incidence of said pulsed beams of known intensity at said work piece from said laser to produce ablation of an opening of specific shape at said work piece;
• the improvement to said ablation process comprising the steps of:
• providing a laser beam sensing subsystem for diverting a fraction of said laser beam;
• analyzing said diverted beam in pointing, coherence, phase and irradiance profile;
• collimation and pointing said laser beam responsive to said laser beam sensing subsystem measured pointing, coherence, and phase;
• and,
• pulsing said laser at said controlled intensity responsive to said analyzed and diverted beam coherence, phase and irradiance profile to produce said opening of specific shape on said work piece.