Disclosed is an apparatus for autonomously compressing, phase-compensating and waveform-shaping an ultrashort light pulse that is fast and high in sensitivity in compensating for phase fluctuations and allows the use of a usual laser light source that is low in light intensity and has large temporal fluctuations in phase. The apparatus comprises: a pulsed light source ( 2 ); a spectroscopic spatial dispersing device ( 4 ) for spatially dispersing a light pulse ( 3 ) emitted from the pulsed light source ( 2 ) into spectral components thereof; a spatial light modulator ( 5 ) for adding a phase to each of the spectral components of the spatially dispersed light pulse ( 3 ); a multiplexer ( 6 ) for combining the phase added spectral components of the light pulse ( 3 ) together to form a composite output light pulse ( 7 ); a modified SPIDER device ( 8 ) for forming a spectral interference figure from a portion of the composite output light pulse ( 7 ); and a feedback device ( 9 ) for detecting a spectral phase from the spectral interference figure and feeding a signal representing a difference between the detected spectral phase and a pre-established phase back to the spatial light modulator ( 5 ). The modified SPIDER device ( 8 ) comprises: a pulsed light source for a chirped light pulse ( 8 a); a delay unit ( 8 c) for delaying a light pulse ( 8 b) from the pulsed light source ( 8 a) with an adjustable delay time; a dispersive medium ( 28 ) for forming a chirped light pulse ( 29 ) from the light pulse whose delay time is adjusted by the delay unit ( 8 c); a replica pulse former ( 24 ) for forming from a portion of the output light pulse ( 7 ) a pair of replica light pulses ( 24 a, 24 b) one delayed after the other; a nonlinear optical crystal ( 31 ) for frequency-mixing the two replica pulses ( 24 a, 24 b) with the chirped light pulse ( 29 ); a spectrometer ( 8 e) for forming an interference figure of the resultant two frequency-mixed replica light pulses; and an image reader ( 8 f) for reading the interference figure of the two frequency-mixed replica light pulses.
Autonomous ultra-short optical pulse compression, phase compensating and waveform shaping device