Material processing utilizing high-frequency beam shaping

Abstract

In various embodiments, laser emissions are steered into different regions of an optical fiber, and/or into different optical fibers, in a temporal pattern such that an output has different spatial output profiles. The temporal pattern has a frequency sufficient such that a workpiece is processed by an effective output shape combining the different spatial output profiles.

1 - 61 . (canceled) 
     
     
         62 . A laser system comprising:
 a beam source for emission of an input laser beam;   an optical fiber having multiple interior regions, in-coupling of an input laser emission into each of the interior regions causing the fiber to produce an output having a different spatial output profile;   a switching mechanism for steering the input laser emission to different ones of the interior regions of the fiber to produce different spatial output profiles in a temporal pattern having a frequency; and   a delivery mechanism for directing the output onto the workpiece while causing relative movement therebetween, thereby processing the workpiece,   wherein the frequency is sufficient such that the workpiece is processed, during the relative movement between the workpiece and the output, by an effective output shape combining the different spatial output profiles.   
     
     
         63 . The system of  claim 62 , wherein the switching mechanism comprises a flexure-mounted reflector. 
     
     
         64 . The system of  claim 62 , wherein the workpiece undergoes a time-based response to the output based on the spatial output profile and a power density thereof, the switching mechanism being configured to limit the relative movement to a maximum processing speed (i) selected based on the time-based response of the material and the frequency of the temporal pattern and (ii) ensuring that the response is to the effective output shape. 
     
     
         65 - 67 . (canceled) 
     
     
         68 . The system of  claim 62 , further comprising a waveform generator for generating a control waveform, the switching mechanism being configured to steer the input laser emission in response to the control waveform. 
     
     
         69 . The system of  claim 68 , wherein the control waveform is a square wave. 
     
     
         70 . The system of  claim 68 , wherein the effective output shape is a weighted average of the different spatial output profiles based on a shape and duty cycle of the control waveform. 
     
     
         71 - 75 . (canceled) 
     
     
         76 . The system of  claim 62 , wherein the beam source comprises:
 one or more beam emitters emitting a plurality of discrete beams;   focusing optics for focusing the plurality of beams toward a dispersive element;   the dispersive element for receiving and dispersing the received focused beams; and   a partially reflective output coupler positioned to receive the dispersed beams, transmit a portion of the dispersed beams therethrough as the input laser emission, and reflect a second portion of the dispersed beams back toward the dispersive element,   wherein the input laser emission is composed of multiple wavelengths.   
     
     
         77 . The system of  claim 76 , wherein the dispersive element comprises a diffraction grating. 
     
     
         78 - 79 . (canceled) 
     
     
         80 . The system of  claim 62 , wherein the optical fiber comprises (i) a central core having a first refractive index, (ii) surrounding the central core, a first cladding having a second refractive index, (iii) surrounding the first cladding, an annular core having a third refractive index, and (iv) surrounding the annular core, a second cladding having a fourth refractive index, wherein (i) the first refractive index is larger than the fourth refractive index, (ii) the third refractive index is larger than the fourth refractive index, and (iii) the second refractive index is smaller than the first refractive index and larger than the fourth refractive index. 
     
     
         81 . The system of  claim 80 , wherein the third refractive index is larger than the first refractive index. 
     
     
         82 . The system of  claim 62 , wherein the optical fiber comprises (i) a center core having a first refractive index, (ii) surrounding the center core, a first cladding having a second refractive index smaller than the first refractive index, (iii) an annular core surrounding the first cladding, and (iv) surrounding the annular core, a second cladding having a third refractive index smaller than the first refractive index, 
 wherein the annular core comprises: 
 a first region having a fourth refractive index greater than the second refractive index, and 
 a second region, a refractive index of the second region varying between (i) a fifth refractive index less than or equal to the fourth refractive index and (ii) a sixth refractive index greater than or equal to the second refractive index. 
   
     
     
         83 . The system of  claim 82 , wherein the first region is disposed between the second region and the second cladding. 
     
     
         84 . The system of  claim 82 , wherein the second region is disposed between the first region and the second cladding. 
     
     
         85 . The system of  claim 62 , wherein the optical fiber comprises (i) a center core having a first refractive index, (ii) an annular core surrounding the center core, and (iii) surrounding the annular core, a first cladding having a second refractive index smaller than the first refractive index, 
 wherein the annular core comprises:
 a first region having a third refractive index greater than the second refractive index, and 
 a second region, a refractive index of the second region varying between (i) a fourth refractive index less than or equal to the third refractive index and (ii) a fifth refractive index less than the fourth refractive index. 
   
     
     
         86 . The system of  claim 85 , wherein the first region is disposed between the second region and the first cladding. 
     
     
         87 . The system of  claim 85 , wherein the second region is disposed between the first region and the first cladding. 
     
     
         88 . The system of  claim 62 , wherein the optical fiber comprises (i) a center core having a first refractive index, (ii) surrounding the center core, a first cladding having a second refractive index smaller than the first refractive index, (iii) an annular core surrounding the first cladding, and (iv) surrounding the annular core, a second cladding having a third refractive index smaller than the first refractive index, 
 wherein the annular core comprises: 
 a first region having a fourth refractive index greater than the second refractive index, and 
 a second region having a fifth refractive index greater than the second refractive index and smaller than the fourth refractive index. 
   
     
     
         89 . The system of  claim 88 , wherein the first region is disposed between the second region and the second cladding. 
     
     
         90 . The system of  claim 88 , wherein the second region is disposed between the first region and the second cladding. 
     
     
         91 . The system of  claim 62 , wherein the optical fiber comprises (i) a center core having a first refractive index, (ii) surrounding the center core, a first cladding having a second refractive index smaller than the first refractive index, (iii) an annular core surrounding the first cladding, and (iv) surrounding the annular core, a second cladding having a third refractive index smaller than the first refractive index, 
 wherein the annular core comprises:
 a first region having a fourth refractive index greater than the second refractive index, 
 a second region having a fifth refractive index greater than the second refractive index, and 
 a third region, disposed between the first and second regions, having a sixth refractive index smaller than the fourth and fifth refractive indices. 
   
     
     
         92 . The system of  claim 91 , wherein the annular core comprises:
 a fourth region having a seventh refractive index greater than the second refractive index; and   a fifth region, disposed between the second and fourth regions, having an eighth refractive index smaller than the fifth and seventh refractive indices.   
     
     
         93 . The system of  claim 62 , wherein the optical fiber comprises (i) a center core, wherein a refractive index of the center core (a) is equal to a first refractive index at a center portion of the center core and (b) decreases, over at least a portion of a radius of the center core, to a second refractive index smaller than the first refractive index, (ii) surrounding the center core, a first cladding having a third refractive index smaller than the first refractive index, (iii) an annular core surrounding the first cladding, and (iv) surrounding the annular core, a second cladding having a fourth refractive index smaller than the first refractive index, 
 wherein the annular core comprises:
 a first region having a fifth refractive index greater than the third refractive index, 
 a second region having a sixth refractive index greater than the third refractive index, and 
 a third region, disposed between the first and second regions, having a seventh refractive index smaller than the fifth and sixth refractive indices. 
   
     
     
         94 - 122 . (canceled)