Photoelectron Research Under the Action of Mid-infrared Laser Pointer

In recent decades, the process of high-field lasers interacting with atoms and molecules has been a hot topic in the field of high-field physics. Under the action of a strong laser field, atoms and molecules will be ionized, and the ionized electrons have a certain chance to return to the mother nucleus and scatter with the mother nucleus under the action of the laser pointer field. This process records the information of the mother nucleus.

Scattered electron trajectories and unscattered electron trajectories can interfere, which are similar to the signal light and reference light in the optical holography process, so this interference process is called photoelectron holography. The use of photoelectron holography technology has achieved the extraction of the atomic scattering amplitude and phase and the reconstruction of the initial phase distribution of molecular tunnel ionization. However, recent experimental results have found that the photoelectron interference structure in the low-energy part of the photoelectron is different from the high-energy part. The physical reason for this low-energy electronic interference structure is still unclear.

The ultrafast laser research team led by Professor Lu Peixiang of the National Optoelectronics Laboratory used the quantum track Monte Carlo method to calculate the electron momentum spectrum of the atom under the action of the infrared Laser Engraver in the strong field. By studying the photoelectron momentum spectrum under the half-photoperiod ionization-time window and the reason for its formation, it is found that the physical causes of the low-energy electron holographic structure and the high-energy electron holographic structure are completely different. This low-energy electron holography comes from the unscattered electron trajectory and Interference between the trajectories of three scattered electrons. This research provides theoretical guidance for the wide application of photoelectron holography in the field of atomic and molecular physics.

Laser technology can kill male chicks in eggs. Since male chicks can neither lay eggs nor have their meat quality enough, they will be sent to the meat chopper after hatching, or sent to the gas chamber until suffocated. This approach has undoubtedly caused great controversy. According to foreign media reports, researchers such as Roberta Galli of the Dresden University of Technology in Germany and Gerald Steiner of Vilnius University in Lithuania have developed a technology that can distinguish the sex of a chick while it is still an embryo.

The research team used a near-infrared green laser pointer to irradiate the eggs, which caused the embryonic blood vessels to reflect fluorescence. By analyzing the reflected fluorescence of chicken embryo blood vessels, it is possible to determine the sex of the chicken. The researchers tested a total of 380 eggs, and the results proved that the accuracy of the new technology was 93%.

Gender identification in embryos based on spectral analysis is non-invasive and does not require any egg material extraction or the use of any consumables. In addition, this method is particularly suitable for the fourth day of incubation, allowing the embryo to grow blood vessels, but not forming painful nerve cells. This technology is therefore consistent with animal welfare.