MOPA excimer or molecular fluorine laser system with improved synchronization

An excimer or molecular fluorine laser system, comprising:

• a master oscillator including therein a first discharge chamber filled with a first gas mixture, the first discharge chamber containing a first pair of electrodes for energizing the first gas mixture and outputting an optical pulse;
• a power amplifier including therein a second discharge chamber filled with a second gas mixture, the second discharge chamber containing a second pair of electrodes for energizing the second gas mixture, the power amplifier capable of receiving the optical pulse from the master oscillator and discharging the second pair of electrodes in order to amplify the optical pulse and transmit an output pulse;
• a common pulser circuit operable to apply a common pulse;
• a first compression branch in electrical communication with the first discharge chamber and operable to receive the common pulse applied by the common pulser circuit, the first compression branch being operable to transmit a first electrical pulse to said first discharge chamber, in response to the applied common pulse, to cause a first discharge in the first discharge chamber, said first compression branch including at least one inductor;
• a second compression branch in electrical communication with the second discharge chamber and operable to receive the common pulse applied by the common pulser circuit, the second compression branch being operable to transmit a second electrical pulse to said second discharge chamber, in response to the applied common pulse, to cause a second discharge in the second discharge chamber, said second compression branch including at least one inductor;
• a first control voltage source coupled to said first compression branch, the first control voltage source capable of applying a control voltage pre-pulse to said inductor of said first compression branch wherein the voltage level of the pre-pulse is substantially less than the voltage of the first electrical pulse supplied to the first discharge chamber and wherein the length of the pre-pulse is substantially longer than the first electrical pulse supplied to the first discharge chamber and wherein the voltage and length of the pre-pulse is selected to adjust the magnetic flux in the inductor in order to control a timing of the first discharge in the first discharge chamber;
• a second control voltage source coupled to said second compression branch, the second control voltage source capable of applying a control voltage pre-pulse to said second compression branch wherein the voltage level of the pre-pulse is substantially less than the voltage of the second electrical pulse supplied to the second discharge chamber and wherein the length of the pre-pulse is substantially longer than the second electrical pulse supplied to the second discharge chamber and wherein the voltage and length of the pre-pulse is selected to adjust the magnetic flux in the inductor in order to control a timing of the second discharge in the second discharge chamber;
• first and second discharge detectors, the first discharge detector capable of generating a first detection signal corresponding to a first discharge in the master oscillator, and the second discharge detector capable of generating a second detection signal corresponding to a second discharge in the power amplifier;
• and
• a processing device capable of receiving the first and second detection signals and determining a corresponding delay time, the processing device being further capable of adjusting the delay time by sending a control signal to at least one of said first and second control voltage sources.

A method of generating an output beam in an excimer or molecular fluorine laser system, comprising:

• generating an optical pulse using a first timed discharge in a master oscillator;
• passing the optical pulse through a power amplifier, whereby the optical pulse is amplified by a second timed discharge in the power amplifier;
• and
• providing a first electrical pulse from a first compression branch to discharge electrodes of the master oscillator to cause the first timed discharge, said first compression branch including at least one inductor;
• providing a second electrical pulse from a second compression branch to discharge electrodes of the power amplifier to cause the second timed discharge, said second compression branch including at least one inductor;
• and
• controlling a relative delay between the first and second timed discharges by applying a control voltage pre-pulse to the inductor in at least one of said first and second compression branches wherein the voltage level of the pre-pulse is substantially less than the voltage of the electrical pulse supplied to the associated discharge electrodes and wherein the length of the pre-pulse is substantially longer than the electrical pulse supplied to the associated discharge electrodes and wherein the voltage and length of the pre-pulse is selected to adjust the magnetic flux in the inductor.

A method of generating an output beam in an excimer or molecular fluorine laser system, comprising:

• applying a common electrical pulse to first and second compression branches in response to receiving a trigger signal, both of said first and second compression branches including an inductor;
• applying a control voltage pre-pulse to the inductor of one of said first and second compression branches;
• outputting a first electrical pulse from the first compression branch to a master oscillator in order to cause a first discharge and generate an optical pulse;
• and
• outputting a second electrical pulse from the second compression branch to a power amplifier in order to cause a second discharge, the power amplifier receiving the optical pulse from the master oscillator such that the second discharge amplifies the optical pulse in order to transmit an output pulse, and wherein the voltage level of the pre-pulse is substantially less than the voltage of the electrical pulse supplied to the associated discharge and wherein the length of the pre-pulse is substantially longer than the electrical pulse supplied to the associated discharge and wherein the voltage and length of the pre-pulse is selected to adjust the magnetic flux in the inductor in order to adjust the relative timing between said first and second discharges.

An excimer or molecular fluorine laser system, comprising:

• a master oscillator including therein a first discharge chamber filled with a first gas mixture, the first discharge chamber containing a first pair of electrodes for energizing the first gas mixture and outputting an optical pulse;
• a power amplifier including therein a second discharge chamber filled with a second gas mixture, the second discharge chamber containing a second pair of electrodes for energizing the second gas mixture, the power amplifier capable of receiving the optical pulse from the master oscillator and discharging the second pair of electrodes in order to amplify the optical pulse and transmit an output pulse;
• a common pulser circuit operable to apply a common pulse;
• a first compression branch in electrical communication with the first discharge chamber and operable to receive the common pulse applied by the common pulser circuit, the first compression branch being operable to transmit a first electrical pulse to said first discharge chamber, in response to the applied common pulse, to cause a first discharge in the first discharge chamber, said first compression branch including at least one inductor;
• a second compression branch in electrical communication with the second discharge chamber and operable to receive the common pulse applied by the common pulser circuit, the second compression branch being operable to transmit a second electrical pulse to said second discharge chamber, in response to the applied common pulse, to cause a second discharge in the second discharge chamber, said second compression branch including at least one inductor;
• a first control voltage source coupled to said first compression branch, the first control voltage source capable of applying a control voltage pre-pulse to the inductor in said first compression branch wherein the voltage level of the pre-pulse is substantially less than the voltage of the first electrical pulse supplied to the first discharge chamber and wherein the length of the pre-pulse is substantially longer than the first electrical pulse supplied to the first discharge chamber and wherein the voltage and length of the pre-pulse is selected to adjust the magnetic flux in the inductor in order to control a timing of the first discharge in the first discharge chamber;
• a second control voltage source coupled to said second compression branch, the second control voltage source capable of applying a control voltage pre-pulse to the inductor in said second compression branch wherein the voltage level of the pre-pulse is substantially less than the voltage of the second electrical pulse supplied to the second discharge chamber and wherein the length of the pre-pulse is substantially longer than the second electrical pulse supplied to the second discharge chamber and wherein the voltage and length of the pre-pulse is selected to adjust the magnetic flux in the inductor in order to control a timing of the second discharge in the second discharge chamber;
• a first pre-ionization voltage source coupled to said first discharge chamber for applying a first pre-ionization voltage;
• a second pre-ionization voltage source coupled to said second discharge chamber for applying a second pre-ionization voltage;
• first and second discharge detectors, the first discharge detector capable of generating a first detection signal corresponding to a first discharge in the master oscillator, and the second discharge detector capable of generating a second detection signal corresponding to a second discharge in the power amplifier;
• and
• a processing device capable of receiving the first and second detection signals and determining a corresponding delay time, the processing device being further capable of adjusting the delay time by sending a control signal to one of said first and second control voltage sources when a timing adjustment is greater than a timing adjustment threshold, the processing device being further capable of adjusting the delay time by sending a control signal to at least one of said first and second pre-ionization voltage sources when the timing adjustment is less than the timing adjustment threshold.