Patent ID: 7649188

Claim:
An LPP (laser produced plasma) type extreme ultra violet light source apparatus comprising: a driver laser for said extreme ultra violet light source apparatus, said driver laser including (i) a short-pulse multi-line oscillated CO 2 laser oscillator including a device having a wavelength-dependent transmittance that suppresses amplitude of an oscillation spectrum exhibiting an energy peak value and does not suppress intensity of spectrum components with low peak intensity and a device that shortens width of pulses included in a laser beam to be output by cutting the laser beam into a desired pulse width, and (ii) at least one amplifier that inputs the laser beam output from said short-pulse multi-line oscillated CO 2 laser oscillator and amplifies the input laser beam to output the amplified laser beam; a target supplier that supplies a target material; and an optical system that guides the laser beam output from said driver laser such that the target material supplied from said target supplier is irradiated with the laser beam.