Phased array steering for laser beam positioning systems

Abstract

A laser beam positioning system of a laser-based specimen processing system produces at beam positioner stage, from a fully fiber-coupled optics phased array laser beam steering system, a steered laser input beam. System directs beam through one or more other beam positioner stages to form a processing laser beam that processes target features of a workpiece mounted on a support.

What is claimed is: 
     
         1 . A method for phased array modulation of a laser beam, comprising:
 generating at least one laser pulse;   splitting each laser pulse of the at least one laser pulse into a plurality of beamlets;   within a phase modulator array, phase-modulating the plurality of beamlets to produce phase differences between the beamlets;   propagating the phase-modulated plurality of beamlets from the phase modulator array to a common amplifier; and   within the amplifier, amplifying the phase-modulated plurality of beamlets, thereby producing an amplified laser beam having at least one laser pulse,   wherein producing phase differences between the beamlets comprises producing, sequentially, at least two phase differences between beamlets split from the same laser pulse of the at least one laser pulse.   
     
     
         2 . The method of  claim 1 , wherein producing phase differences between the beamlets comprises controlling an operation of the phase modulator array to produce phase differences between the beamlets in a manner that causes a wave front of different portions of the same laser pulse to be different from each other. 
     
     
         3 . The method of  claim 1 , wherein producing phase differences between the beamlets comprises controlling an operation of the phase modulator array to produce phase differences between the beamlets in a manner that causes different portions of the same laser pulse to be focused differently from each other. 
     
     
         4 . The method of  claim 1 , wherein producing phase differences between the beamlets comprises controlling an operation of the phase modulator array to produce phase differences between the beamlets in a manner that causes different portions of the same laser pulse to be steered to different locations. 
     
     
         5 . The method of  claim 1 , wherein producing the at least two phase differences between the beamlets comprises controlling an operation of the phase modulator array according to a linear phase delay profile. 
     
     
         6 . The method of  claim 1 , wherein producing the at least two phase differences between the beamlets comprises controlling an operation of the phase modulator array according to a parabolic phase delay profile. 
     
     
         7 . The method of  claim 1 , wherein the at least one laser pulse has a pulse duration greater than 1 ns. 
     
     
         8 . The method of  claim 1 , wherein producing phase differences between the beamlets comprises changing an operation of the phase modulator array at a rate in a range from 1 kHz to 1 GHz. 
     
     
         9 . An apparatus, comprising:
 a splitter configured to split a laser beam into a plurality of beamlets;   a phase modulator array optically coupled to the splitter and operative to phase-modulate the beamlets to produce phase differences between the beamlets;   an amplifier optically coupled to the phase modulator array and operative to amplify the phase-modulated plurality of beamlets, thereby producing an amplified beam; and   phase modulation electronics operably coupled to the phase modulator array and configured to command some modulators of the phase modulator array to delay corresponding ones of the beamlets to produce phase differences between the beamlets in a manner that changes a wave front of laser pulses in the amplified laser beam such that the wavefront of the amplified laser beam changes at least once.   
     
     
         10 . The apparatus of  claim 9 , wherein the amplifier is a multicore photonic crystal fiber amplifier. 
     
     
         11 . The apparatus of  claim 9 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to produce phase differences between the beamlets in a manner that causes different portions of the amplified laser beam to be steered to different locations. 
     
     
         12 . The apparatus of  claim 9 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to produce phase differences between the beamlets in a manner that causes different portions of the same amplified laser beam to be focused differently from each other. 
     
     
         13 . The apparatus of  claim 9 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to delay corresponding ones of the beamlets according to a linear phase delay profile. 
     
     
         14 . The apparatus of  claim 9 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to delay corresponding ones of the beamlets according to a parabolic phase delay profile. 
     
     
         15 . The apparatus of  claim 9 , further comprising a three-dimensional waveguide optically coupled between an output of the phase modulator array and an input of the amplifier, the waveguide operative to receive the beamlets and deliver the received beamlets to the amplifier. 
     
     
         16 . The apparatus of  claim 9 , further comprising a seed laser configured to generate the laser beam. 
     
     
         17 . The apparatus of  claim 9 , wherein the laser beam comprises a plurality of laser pulses. 
     
     
         18 . The apparatus of  claim 17 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to produce, sequentially, at least two phase differences between beamlets split from the same laser pulse of the at least one laser pulse. 
     
     
         19 . The apparatus of  claim 18 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to produce phase differences between the beamlets in a manner that causes a wave front of different portions of the same laser pulse to be different from each other. 
     
     
         20 . The apparatus of  claim 18 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to produce phase differences between the beamlets in a manner that causes different portions of the same laser pulse to be focused differently from each other. 
     
     
         21 . The apparatus of  claim 18 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to produce phase differences between the beamlets in a manner that causes different portions of the same laser pulse to be steered to different locations. 
     
     
         22 . The apparatus of  claim 18 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to delay corresponding ones of the beamlets according to a linear phase delay profile. 
     
     
         23 . The apparatus of  claim 18 , wherein the phase modulation electronics is configured to command some modulators of the phase modulator array to delay corresponding ones of the beamlets according to a parabolic phase delay profile.