Methods and apparatus for measuring and locking ultra-fast laser pulses

An all-phase measurement device associated with an ultra-fast laser pulse, comprising:

• an ultra-fast laser source for emitting an ultra-fast laser pulse having a spectral range greater than one octave;
• a beam splitting element for splitting the ultra-fast laser pulse into a first beam that comprises a fundamental light with a wavelength λ0 and a second beam that comprises a light with a wavelength 2λ0;
• at least one optical path adjusting member for adjusting an optical path of the first beam or the second beam;
• a beam combining element disposed behind the at least one optical path adjusting member for combining the first beam and the second beam;
• a frequency doubling crystal for frequency doubling the light with the wavelength 2λ0 to a light with a wavelength λ0;
• a polarization adjusting member for adjusting polarization directions of the fundamental light and the frequency doubled light to cause an interference therebetween;
• a spectral acquisition device for acquiring a spectral pattern of the interference;
• and
• a data processing unit for performing Fourier transform on the spectral pattern of the interference, and extracting a relative envelope delay (RED) between the fundamental light and the frequency doubled light and a carrier envelope phase (CEP);
• wherein an abscissa and an ordinate of a first peak of the result of the Fourier transform represent the RED and a total relative phase (RTP), respectively.