Patent ID: 8451531

Claim:
A light amplifier, comprising: a first amplifier including a first light amplification medium excited by a first light pulse, for amplifying an input laser light pulse in an excited state, and a first optical system for forming a first optical path for said laser light pulse to pass through said first light amplification medium a plurality of times; a second amplifier including a second light amplification medium excited by a second light pulse, for amplifying, when it receives amplified light which is said laser light pulse amplified by said first amplifier, said amplified light in an excited state, a second optical system for forming a second optical path for said amplified light to pass through said second light amplification medium a plurality of times, and at least one light attenuation portion provided in said second optical path, for attenuating energy of said amplified light incident on the light attenuation portion itself; an excitation light source for generating an excitation light pulse for exciting said first and second light amplification media; and a first pulse splitting portion for splitting said excitation light pulse from said excitation light source into said first and second light pulses, and said second optical system being configured such that said amplified light alternately passes through said second light amplification medium and said at least one light attenuation portion and passes through said second amplification medium at least twice.