Euv light source with subsystem(s) for maintaining lpp drive laser output during euv non-output periods

An Extreme Ultraviolet (EUV) light source producing EUV pulses in at least two burst periods, the at least two burst periods separated by an intervening period, the EUV light source comprising:

• a droplet generator producing droplets of target material during each of the at least two burst periods and during the intervening period:
• a laser source producing laser pulses during the each of the at least two burst periods and during the intervening period;
• and
• a system operable to reconfigure the EUV light source from a first configuration in which the laser pulses generated during the each of the at least two burst periods interact with the droplets of target material to produce a plasma having first characteristics and a second configuration in which laser pulses generated during the intervening period do not produce the plasma having the first characteristics, the system changing a focal spot of the laser pulses from a first focal spot location during the each of the at least two burst periods to a second focal spot location during the intervening period.

An Extreme Ultraviolet (EUV) light source producing EUV pulses in at least two burst periods, the at least two burst periods separated by an intervening period, the EUV light source comprising:

• a droplet generator producing droplets of target material during each of the at least two burst periods and during the intervening period;
• a laser source producing laser pulses during the each of the at least two burst periods and during the intervening period;
• and
• a system operable to reconfigure the laser source from a first configuration in which the laser pulses generated during the each of the at least two burst periods interact with the droplets of target material to produce a plasma having first characteristics and a second configuration in which laser pulses generated during the intervening period do not interact with the droplets of target of material to produce the plasma having the first characteristics, wherein the laser pulses produced during the each of the at least two burst periods are timed to impinge on the droplets of target materials and the laser pulses produced during the intervening period are timed to not impinge on the droplets of target material.