Laser systems and methods for large area modification

A method for laser marking of a large area of an article, comprising:

• directing a laser beam for propagation along an optical path;
• propagating the laser beam through a diffractive optical element to create a beamlet group of multiple distinct beamlets including three or more beamlets;
• employing a mobile aperture to distribute the beamlet group into first and second beamlet sets, wherein the first beamlet set includes a number of beamlets, and wherein the beamlet selection device permits the first beamlet set to propagate along the optical path and prevents the second beamlet set from propagating along the optical path;
• and
• coordinating operation of the aperture with operation of a galvanometer mirror positioned along the optical path, wherein the galvanometer mirror affects relative motion and relative position of a beam axis of the laser beam with respect to the article, and wherein movement of the mobile aperture changes the number of beamlets in the first set in coordination with changes made to the relative motion or the relative position of the beam axis with respect to the article.

A laser system for making a large area laser modification of an article, comprising:

• a laser operable for generating a laser beam for propagation along an optical path;
• a beamlet generator operable for creating a beamlet group of multiple distinct beamlets including three or more beamlets;
• a beamlet selection device operable for dividing the beamlet group into first and second beamlet sets, wherein the first beamlet set includes a number of beamlets, and wherein the beamlet selection device is operable to permit the first beamlet set to propagate along the optical path and operable to prevent the second beamlet set from propagating along the optical path;
• a beam positioning system operable for causing relative motion of a beam axis of the laser beam with respect to the article to change of position of the beam axis with respect to the article;
• and
• a controller operable for controlling the relative motion and the relative position of the beam axis with respect to the article and operable for causing the beamlet selection device to change the number of beamlets in the first set in coordination with changes made to the relative motion or the relative position of the beam axis with respect to the article.

A method for facilitating laser modification of a large area of an article, the large area having a desired modification edge with a predetermined modification edge profile, wherein the desired modification edge has a desired localized edge portion with a localized edge profile, comprising:

• propagating a laser beam including a beamlet formation of multiple distinct laser beamlets including three or more laser beamlets simultaneously along an optical path having a beam axis that intersects the article, wherein the beamlet formation corresponds to a spot set of spot areas on the article and provides a one-to-one correspondence of the laser beamlets to the spot areas whenever the respective laser beamlets are permitted to propagate to the article, wherein the spot set has a spot set edge profile that is different from the localized edge profile for the desired modification edge;
• employing a beam positioning system to direct a laser pass of the beam axis in a pass direction relative to desired locations on the article, wherein the pass direction is transverse to the desired localized edge portion of the desired modification edge;
• employing a beamlet selection device during a first time period during the laser pass to block a first number of laser beamlets to prevent propagation of the first number of laser beamlets along the optical path downstream of the beamlet selection device during the first time period and to permit propagation of unblocked laser beamlets along the optical path downstream of the beamlet selection device during the first time period;
• employing the beamlet selection device during a second time period during the laser pass to block a second number of laser beamlets to prevent propagation of the second number of laser beamlets along the optical path downstream of the beamlet selection device during the second time period and to permit propagation of unblocked laser beamlets along the optical path downstream of the beamlet selection device during the second time period, wherein the second number is different from the first number;
• employing the beamlet selection device during a third time period during the laser pass to block a third number of laser beamlets to prevent propagation of the third number of laser beamlets along the optical path downstream of the beamlet selection device during the third time period and to permit propagation of unblocked laser beamlets along the optical path downstream of the beamlet selection device during the third time period, wherein the third number is different from the second number, wherein the first, second, and third numbers affect a propagation edge profile for the laser beam, wherein the propagation edge profile of the laser beam influences a modification edge made by the laser beam;
• and
• coordinating operation of the beamlet selection device with operation of the beam positioning system so that the propagation edge profile of the laser beam differs from the spot set edge profile of the laser beam, so that the propagation edge profile of the laser beam resembles the localized edge profile of the desired localized edge portion of the desired modification edge, so the propagation edge profile of the laser beam is synchronized with the location of the desired localized edge portion of the desired modification edge of the large area.