High-speed, precision, laser-based method and system for processing material of one or more targets within a field

Abstract

A precision, laser-based method and system for high-speed, sequential processing of material of targets within a field are disclosed that control the irradiation distribution pattern of imaged spots. For each spot, a laser beam is incident on a first anamorphic optical device and a second anamorphic optical device so that the beam is controllably modified into an elliptical irradiance pattern. The modified beam is propagated through a scanning optical system with an objective lens to image a controlled elliptical spot on the target. In one embodiment, the relative orientations of the devices along an optical axis are controlled to modify the beam irradiance pattern to obtain an elliptical shape while the absolute orientation of the devices controls the orientation of the elliptical spot.

1 .- 55 . (canceled)  
   
   
       56 . A marking method of selectively processing target material with a precisely controlled ablation threshold, the method comprising: 
 generating, with a narrow pulse laser system, as laser beam along at least one propagation path;    controllably modifying the laser beam to obtain a modified laser beam; and    sequentially and relatively positioning the modified laser beam into a plurality of well-focused spots forming an arbitrary pattern within a field to process the target material wherein at least one of the well-focused spots is an elongated spot having a major axis and a minor axis, wherein the major axis is aligned within the field and wherein the precisely controlled ablation threshold allows for selective material processing and wherein each of the well-focused spots has a set of desired spatial characteristics which are obtained by the step of controllably modifying.    
   
   
       57 . The method as claimed in  claim 56 , wherein the arbitrary pattern includes a series of overlapping spots.  
   
   
       58 . The method as claimed in  claim 57 , wherein the overlapping spots form linear, curvilinear or multi-segment lines.  
   
   
       59 . The method as claimed in  claim 57 , wherein the overlapping spots form laser kerfs.  
   
   
       60 . The method as claimed in  claim 56 , wherein the arbitrary pattern corresponds to rows or columns.  
   
   
       61 . The method as claimed in  claim 60 , wherein the rows or columns are parallel.  
   
   
       62 . The method as claimed in  claim 56 , wherein at least a portion of the arbitrary pattern is a specified code.  
   
   
       63 . The method as claimed in  claim 62  further comprising: 
 providing the specified code;    providing a target position; and    correlating the spots forming the code and the target position.    
   
   
       64 . The method as claimed in  claim 56 , wherein the target material is a metal.  
   
   
       65 . The method as claimed in  claim 56 , wherein the step of generating includes utilizing an external modulator to provide laser pulses on demand, each pulse being correlated to a target position.  
   
   
       66 . The method as claimed in  claim 56 , wherein the step of positioning includes vector or random access scanning.  
   
   
       67 . The method as claimed in  claim 56 , wherein the laser beam is generated along a plurality of paths and wherein each path provides control of a spot feature.  
   
   
       68 . A marking method of selectively processing target material with a precisely controlled ablation threshold, the method comprising: 
 generating, with a narrow pulse laser system, a laser beam along at least one propagation path wherein the step of generating includes utilizing an external modulator to provide laser pulses on demand, each pulse being correlated to a position of a target;    controllably modifying the laser beam to obtain a modified laser beam; and    sequentially and relatively positioning the modified laser beam into a plurality of well-focused spots which form an arbitrary pattern within a field to process the target material wherein at least one of the well-focused spots has an adjustable aspect ratio and a feature aligned within the field and wherein the precisely controlled ablation threshold allows for selective material processing and wherein each of the well-focused spots has a set of desired spatial characteristics which are obtained by the step of controllably modifying.    
   
   
       69 . A marking system for selectively processing target material with a precisely controlled ablation threshold, the system comprising: 
 a narrow pulse laser source for generating a laser beam along at least one propagation path;    a controller for generating control signals;    a subsystem for controllably modifying the laser beam in response to the control signals to obtain a modified laser beam; and    a beam delivery and focusing subsystem for sequentially and relatively positioning the modified laser beam into a plurality of well-focused spots which form an arbitrary pattern within a field to process the target material wherein at least one of the well-focused spots is an elongated spot having a major axis and a minor axis wherein the major axis is aligned within the field and wherein the precisely controlled ablation threshold allows for selective material processing and wherein each of the well-focused spots has a set of desired spatial characteristics.    
   
   
       70 . The system as claimed in  claim 69  further comprising an external modulator to provide laser pulses on demand, each pulse being correlated to a position of a target.  
   
   
       71 . The system as claimed in  claim 69 , wherein the beam delivery and focusing subsystem is a multi-axis scanning subsystem that includes a combination of low-inertia, beam-positioning systems.  
   
   
       72 . The system as claimed in  claim 71 , wherein the combination of low-inertia, beam-positioning systems include at least one of a galvanometer, a sold state beam deflector, a micro-mirror, a light weight diffractive optical element and a moving lens.  
   
   
       73 . The system as claimed in  claim 69 , wherein the narrow pulse laser source is a picosecond laser.  
   
   
       74 . The system as claimed in  claim 69 , wherein the narrow pulse laser source is a femtosecond laser.  
   
   
       75 . The system as claimed in  claim 69  further comprising an optical switch configured to switch the laser beam between a plurality of propagation paths, the switch switching between at least two of the propagation paths.