Patent ID: 7102810

Claim:
A method for ultra-fast conversion of time signal into two-dimensional space signal, the method comprising: introducing a signal light pulse and a reference ultra-short light pulse having an appropriate width in space into a nonlinear crystal through a dispersion device and a one-dimensional Fourier transformation optical system; subjecting a second-harmonic, which is generated by satisfying a phase matching condition in the nonlinear crystal, to time-to-space conversion through an inverse one-dimensional Fourier transformation optical system so as to be converted into a one-dimensional space distribution; and subjecting the time-to-space converted one-dimensional space distribution to filtering with a time-frequency filter provided on a filter plane of a one-dimensional space frequency filtering optical system, wherein a time-frequency expanded two-dimensional light distribution representing a relation between time and frequency of the signal light pulse is regarded as a two-dimensional space signal.