Very high repetition rate narrow band gas discharge laser system

Abstract

A laser system and method is disclosed which may comprise a first line narrowed gas discharge laser system producing a first laser output light pulse beam at a pulse repetition rate of ≧2000 Hz; a second line narrowed gas discharge laser system producing a second laser output light pulse beam at a pulse repetition rate of ≧2000 Hz; a beam combiner combining the first and second output light pulse beams into a combined laser output light pulse beam with a ≧4000 Hz pulse repetition rate. The apparatus and method may comprise a compression head comprising a storage device being charged at x times per second; a gas discharge chamber comprising at least two sets of paired gas discharge electrodes; at least two magnetically saturable switches, respectively connected between the compression head charge storage device and one of the at least two sets of paired electrodes.

1 . A very high repetition rate gas discharge laser system in a MOPO configuration comprising: 
 a first line narrowed gas discharge laser system producing a first laser output light pulse beam at a pulse repetition rate of ≧2000 Hz;    a second line narrowed gas discharge laser system producing a second laser output light pulse beam at a pulse repetition rate of ≧2000 Hz;    a beam combiner combining the first and second output light pulse beams into a combined laser output light pulse beam with a ≧4000 Hz pulse repetition rate.    
     
     
         2 . The apparatus of  claim 1  further comprising: 
 the first laser output light pulse beam is produced at a pulse repetition rate of ≧4000 Hz and the second laser output light pulse beam is produced at a rate of ≧4000.    
     
     
         3 . The apparatus of  claim 1  further comprising: 
 the first laser output light pulse beam is produced at a pulse repetition rate of ≧5000 Hz and the second laser output light pulse beam is produced at a rate of ≧5000.    
     
     
         4 . The apparatus of  claim 1  further comprising: 
 a beam delivery unit connected to the laser light output of the power amplification laser system and directing the output of the power amplification laser system to an input of a light utilization tool and providing at least beam pointing and direction control.    
     
     
         5 . The apparatus of  claim 2  further comprising: 
 a beam delivery unit connected to the laser light output of the power amplification laser system and directing the output of the power amplification laser system to an input of a light utilization tool and providing at least beam pointing and direction control.    
     
     
         6 . The apparatus of  claim 3  further comprising: 
 a beam delivery unit connected the laser light output of the power amplification laser system and directing to the output of the power amplification laser system to an input of a light utilization tool and providing at least beam pointing and direction control.    
     
     
         7 . A very high repetition rate gas discharge laser system comprising: 
 a compression head comprising a compression head charge storage device being charged at x times per second;    a gas discharge chamber comprising at least two sets of paired gas discharge electrodes;    at least two magnetically saturable switches, respectively connected between the compression head charge storage device and one of the at least two sets of paired electrodes and comprising first and second opposite biasing windings having a first biasing current for the first biasing winding and a second biasing current for the second biasing winding and comprising a switching circuit to switch the biasing current from the first biasing current to the second biasing current such that only one of the at least two switches receives the first biasing current at a repetition rate equal to x divided by the number of the at least two sets of paired electrodes while the remainder of the at least two magnetically saturable switches receives the second biasing current.    
     
     
         8 . The apparatus of  claim 7  further comprising: 
 the at least two sets of paired gas discharge electrodes is two sets of paired gas discharge electrodes;    the at least two magnetically saturable switches is two magnetically saturable switches; and    the switching circuit switches the first biasing current to one of the two magnetically saturable switches while switching the second biasing current to the second magnetically saturable switch.    
     
     
         9 . The apparatus of  claim 7  further comprising: 
 the at least two sets of paired gas discharge electrodes are positioned in parallel within the gas discharge chamber;    a gas circulation system circulating gas through the gas discharge chamber in a flow path that first encompasses a gap between the first set of paired electrodes and then encompasses a gap between the second set of paired electrodes;    a gas converter between the first and second set of paired gas discharge electrodes in the gas flow path.    
     
     
         10 . The apparatus of  claim 8  further comprising: 
 the at least two sets of paired gas discharge electrodes are positioned in parallel within the gas discharge chamber;    a gas circulation system circulating gas through the gas discharge chamber in a flow path that first encompasses a gap between the first set of paired electrodes and then encompasses a gap between the second set of paired electrodes;    a gas converter between the first and second set of paired gas discharge electrodes in the gas flow path.    
     
     
         11 . The apparatus of  claim 7  further comprising: 
 at least two line narrowing packages each optically interconnected to a respective one of the at least two sets of paired gas discharge electrodes.    
     
     
         12 . The apparatus of  claim 8  further comprising: 
 at least two line narrowing packages each optically interconnected to a respective one of the at least two sets of paired gas discharge electrodes.    
     
     
         13 . The apparatus of  claim 9  further comprising: 
 at least two line narrowing packages each optically interconnected to a respective one of the at least two sets of paired gas discharge electrodes.    
     
     
         14 . The apparatus of  claim 10  further comprising: 
 at least two line narrowing packages each optically interconnected to a respective one of the at least two sets of paired gas discharge electrodes.    
     
     
         15 . The apparatus of  claim 7  further comprising: 
 the at least two sets of paired gas discharge electrodes is two sets of paired gas discharge electrodes;    a single line narrowing package comprising:    a diffractive bandwidth selection optic;    a first optical path to the line narrowing package aligned with a first set of paired gas discharge electrodes comprising a first polarizing beam splitter that is essentially fully transmissive to laser light pulses of a first polarization and essentially fully reflective to laser light pulses of a second polarization;    first and second cavity windows aligned with the first optical path polarizing the laser output light pulses from the first set of paired electrodes in the first polarization direction;    first and second cavity windows aligned with the second set of paired electrodes polarizing the laser output light pulses from the second set of paired electrodes in the second polarization direction;    a beam reflector reflecting the laser output light pulses from the second set of paired electrodes into the first polarizing beam splitter;    a first polarizing mechanism between the first polarizing beam splitter and the diffractive bandwidth selection optic polarizing the output laser light pulses from the second set of paired electrodes to the first polarization when input into the diffractive bandwidth selection optic, and re-polarizing the output laser light pulses from the second set of paired electrodes to the second polarization direction upon return from the diffractive bandwidth selection optic;    a second polarizing beam splitter on the output of the laser output light pulses from the first set of paired electrodes that is essentially fully transmissive of laser output light pulses of the first polarization and essentially fully reflective of laser output light pulses of the second polarization;    a beam reflector reflecting the laser output light pulses from the second set of paired electrodes to the second polarizing beam splitter.    
     
     
         16 . The apparatus of  claim 15  further comprising: 
 a second polarizing mechanism polarizing the laser output light pulses from the second set of paired electrodes reflected in the second polarizing beam splitter to the first polarization direction.    
     
     
         17 . The apparatus of  claim 15  further comprising: 
 the first and/or the second polarizing mechanism is a dithered half wave plate that is dithered into and out of the optical path to the diffractive bandwidth selection optic depending on the presence or absence of light generated between the second set of paired electrodes.    
     
     
         18 . The apparatus of  claim 16  further comprising: 
 the first and/or the second polarizing mechanism is a dithered half wave plate that is dithered into and out of the optical path to the diffractive bandwidth selection optic depending on the presence or absence of light generated between the second set of paired electrodes.    
     
     
         19 . The apparatus of  claim 15  further comprising: 
 the first and/or second polarizing mechanism is an excited optical element modulated at the output laser light pulse pulse repetition rate.    
     
     
         20 . The apparatus of  claim 16  further comprising: 
 the first and/or second polarizing mechanism is an excited optical element modulated at the output laser light pulse pulse repetition rate.    
     
     
         21 . The apparatus of  claim 17  further comprising: 
 the first and/or second polarizing mechanism is an excited optical element modulated at the output laser light pulse pulse repetition rate.    
     
     
         22 . The apparatus of  claim 18  further comprising: 
 the first and/or second polarizing mechanism is an excited optical element modulated at the output laser light pulse pulse repetition rate.    
     
     
         23 . A method of producing very high repetition rate gas discharge laser pulses comprising: 
 utilizing a very high repetition rate gas discharge laser system in a MOPO configuration comprising:    a first line narrowed gas discharge laser system producing a first laser output light pulse beam at a pulse repetition rate of ≧2000 Hz;    a second line narrowed gas discharge laser system producing a second laser output light pulse beam at a pulse repetition rate of ≧2000 Hz;    a beam combiner combining the first and second output light pulse beams into a combined laser output light pulse beam with a ≧4000 Hz pulse repetition rate.