Patent ID: 8599889

Claim:
A pulsed light source comprising: pulse generation means ( 1 ) adapted to generate a pulsed signal at a first wavelength; a first idler arm ( 3 ) adapted to receive the pulsed signal from the pulse generation means ( 1 ) and to generate a first auxiliary signal at the first wavelength; a second idler arm ( 4 ) adapted to receive the pulsed signal from the pulse generation means ( 1 ) and comprising first shifting means ( 6 ) adapted to generate a second auxiliary signal at a second wavelength; signal mixing means ( 8 ) adapted to mix the first auxiliary signal and the second auxiliary signal and to generate a idler output at a third wavelength; a pump arm ( 5 ) adapted to receive the pulsed signal from the pulse generation means ( 1 ) and to generate a pump output; at least one optical parametric chirped-pulse amplification stage ( 13 ) adapted to receive the idler output and the pump output and to amplify the idler output; a pulse compressor ( 14 ) adapted to reduce a temporal length of the amplified idler output and to generate ultrashort light pulses; pulse stretching means ( 9 ) adapted to stretch pulses of the idler output; wavelength narrowing means ( 11 ) adapted to reduce the spectral bandwidth of the pump output; and fibre amplifiers ( 2 ) in the first idler arm ( 3 ), the second idler arm ( 4 ) and the pump arm ( 5 ) adapted to amplify the pulsed signal from the pulse generation means ( 1 ), wherein the first idler arm ( 3 ) and the second idler arm ( 4 ) are adapted to maintain the same carrier envelope phase between the first auxiliary signal and the second auxiliary signal, wherein said carrier envelope phase comprises a random variation; the signal mixing means ( 8 ) are adapted to cancel the random variation of the carrier envelope phase; the at least one optical parametric chirped-pulse amplification stage ( 13 ) is adapted to preserve the carrier envelope phase; and the pulse compressor is adapted to generate the ultrashort light pulses with a stable carrier envelope phase.