High harmonic generation for N2 and CO2 beyond the two-point model
نویسندگان
چکیده
Strong field high harmonic generation (HHG) can reveal the quantum structure of the source molecule. We calculate the effect of interference between the recombining photoelectron and the orbital from which it was field ionized in the single-active-electron standard picture of HHG in N2 and CO2. We compare our results for the highest occupied molecular orbitals (HOMO’s) to the predictions of a popular two-point scattering model. For N2, we find an agreement for very large internuclear separations and no agreement for the ground-state internuclear distance. We reduce the arguments to the Fourier transform of the HOMO, which depends on the internuclear separation. For CO2, we distinguish between two geometries. For one of these, we find a perfect agreement with the two-point scattering model; however, the emitted radiation is not phase matched in this case. The experimentally accessible radiation does not agree with the simple model.
منابع مشابه
Mapping molecular orbital symmetry on high-order harmonic generation spectrum using two-color laser fields.
We have measured high-order harmonic generation spectra of D2, N2, and CO2 by mixing orthogonally polarized 800 and 400 nm laser fields. The intensity of the high-harmonic spectrum is modulated as we change the relative phase of the two pulses. For randomly orientated molecules, the phase of the intensity modulation depends on the symmetry of the molecular orbitals from which the high harmonics...
متن کاملHigh Harmonic Phase in Molecular Nitrogen
Electronic structure in atoms and molecules modulates the amplitude and phase of high harmonic generation (HHG). We report measurements of the high harmonic spectral amplitude and phase in N2. The phase is measured interferometrically by beating the N2 harmonics with those of an Ar reference oscillator in a gas mixture. A rapid phase shift of 0.2π is observed in the vicinity of the HHG spectral...
متن کاملInvestigating Characteristics of N2, CO2 and CF3I in Contrast to High Current Arcs in Circuit Breakers to Choose a Suitable Substitute for SF6
Specific and sensitive operation of circuit breakers makes an individual position for them in power networks. Circuit breakers are at the central gravity of variations and execution operations. Therefore, an optimum operation is the main reason to investigate about new gases to be used in MV and HV circuit breakers instead of SF6. The arc process has enormous complexity because of hydrodynamic ...
متن کاملControlling the interference of multiple molecular orbitals in high-harmonic generation.
We demonstrate a new method to investigate the origin of spectral structures in high-harmonic generation. We report detailed measurements of high-harmonic spectra in aligned nitrogen and carbon dioxide molecules. Varying the wavelength and intensity of the generating laser field, we show that the minimum in aligned N2 molecules is nearly unaffected, whereas the minimum in aligned CO2 molecules ...
متن کاملHigh-order harmonic cutoff extension of the O2 molecule due to ionization suppression
High-order harmonic generation has been observed experimentally from O2 molecules at the saturation ionization intensity. The harmonic cutoff extends far beyond the cutoff of Xe despite both have nearly equal ionization potentials. In contrast, the harmonic spectra for N2 and Ar, which have almost the same ionization potentials, are essentially close to each other. We show the extension of harm...
متن کامل