Effect of the finite speed of light in ionization of extended molecular systems

We study propagation effects due to the finite speed of light in ionization of extended molecular systems. We present a general quantitative theory of these effects and show under which conditions such effects should appear. The finite speed of light propagation effects are encoded in the non-dipole terms of the time-dependent Shrödinger equation and display themselves in the photoelectron momentum distribution projected on the molecular axis. Our numerical modeling for the $$\hbox {H}_{2}^{+}$$ H 2 + molecular ion and the $$\hbox {Ne}_2$$ Ne 2 dimer shows that the finite light propagation time from one atomic center to another can be accurately determined in a table top laser experiment which is much more readily accessible than the ground breaking synchrotron measurement by Grundmann et al. (Science 370:339, 2020).

Effect of the finite speed of light in ionization of extended molecular systems

We study propagation effects due to the finite speed of light in ionization of extended molecular systems. We present a general quantitative theory of these effects and show under which conditions such effects should appear. The finite speed of light propagation effects are encoded in the non-dipole terms of the time-dependent Shrödinger equation and display themselves in the photoelectron momentum distribution projected on the molecular axis. Our numerical modeling for the H + 2 molecular ion and the Ne 2 dimer shows that the finite light propagation time from one atomic center to another can be accurately determined in a table top laser experiment which is much more readily affordable than the ground breaking synchrotron measurement by Grundmann et al [Science 370, 339 (2020)].

Study on oscillation modes of weld pool in stationary GTA welding using structure laser method

To study the oscillation mode of GTA weld pool, the oscillation mode of weld pool was analyzed based on Bessel equation, and the laser dot matrix images of (0, 1), (1, 1), (2, 1), (0, 2) oscillation modes at different times are obtained by structured laser optical measurement simulation. The oscillation mode of stationary GTA weld pool was analyzed based on the laser dot matrix images obtained by structure laser experiment. The result shows the simulated laser dot matrix images matches up to the experiment result. The oscillation mode of the weld pool can be recognized based on laser dot matrix image. This study can not only provide conditions for judging the penetrating state of weld pool, but also help to further understand the oscillation mode of the weld pool and develop more effective observation methods and measurement tools, so as to effectively control and improve the welding quality.

High-resolution rotational Raman spectroscopy of benzene

A time-domain laser experiment resolved spectra for benzene with single-MHz resolution, a 100-fold improvement on literature data.