Figure 1: Three- and four-photon PECD for fenchone and camphor. On the left: the multiphoton PECD of fenchone computed for the photon wavelength of 380 nm. In the middle: the PECD of fenchone computed for the photon wavelength of 400 nm. On the right: the PECD of camphor computed for the photon wavelength of 360 nm. The photoelectrons emitted due to the three-photon ionization form the inner ring, while the photoelectrons emitted due to the four-photon process the outer ring. The PECD signal is obtained as the relative difference between the electron spectra computed for left and right circularly polarized pulses. The signal is normalized to the maximal intensities of the respective spectrum. The pulse propagates along the laboratory z-axis, which coincides with k_{||}.