Patent ID: 7738516

Claim:
Detection method for undesired double- or multiple-pulse states (DP/MP) in an ultra-short-pulse laser system for generating femtosecond or picosecond pulses, comprising at least an amplifying laser medium for producing a laser emission, a laser resonator having at least one resonator mirror and a pump source, in particular a laser diode source, for pumping the laser medium, the ultra-short-pulse laser system being operated in the soliton regime and a first signal μ proportional to the pulse power P(t) or pulse energy averaged over the resonator cycle being measured for the laser emission, wherein a second signal ν proportional to the square of the pulse power P(t), averaged over the resonator cycle, is measured for the laser emission and the occurrence of an undesired double- or multiple-pulse state (DP/MP) is detected on the basis of a comparison of the measured signals μ and ν which are independent in the range of resonator cycle times.