A new publication from Opto-Electronic Advances considers a north of 20 J THz laser beat created at 1 kHz in gas media.
Terahertz (THz) science and innovation has gotten a lot of attention from logical analysts all over the world in recent years because of its potential applications in security imaging, clinical finding, military, remote correspondence, and cosmology. Nonetheless, the improvement of high-power broadband THz radiation sources has been a difficult errand in the previously mentioned fields.
Among various THz radiation sources, the THz radiation source based on femtosecond laser fiber has the advantages of broadband (200 THz), high adequacy (100 MV/cm), and no harm edge limit.The THz age strategy in view of the femtosecond laser filamentation limits the THz wave inside the fiber, which can kill the diffraction and retention during the spread of the THz wave in the air and make the far-off conveyance of the THz wave become conceivable.
The THz age plot in view of the double variety femtosecond laser filamentation has higher energy change proficiency than that utilizing a single-variety femtosecond laser. In this plan, the power, transfer speed, polarization, and different qualities of the THz radiation can be impacted by numerous laser boundaries, including the worldly deferral, scattering, polarization, frequency, and spatial flight of the double variety fields. Indeed, even the surrounding gas species play a vital part as well. To foster an effective THz radiation source, this multitude of boundaries should be painstakingly planned and controlled.
The exploration group, led by Prof. Weiwei Liu from Nankai College, utilized a femtosecond laser with a single heartbeat energy of 6 mJ to create the double variety laser filamentation by recurrence multiplying the key laser through an -BBO gem. Through a shifted -BBO gem, the double variety laser radiates the ideal spatial-worldly cross-over. In the interim, a double frequency plate was utilized to make the double variety laser radiate have an indistinguishable polarization. The energy of the THz beat created from the laser fiber in argon can depend on 21 J and the corresponding THz change proficiency comes to 0.35%.
In this work, the surrounding gas species’ impact on the THz age proficiency by the double variety laser filamentation was examined tentatively. The trial results show that the most elevated change proficiency of THz radiation is accomplished in argon gas. The connection between the shifting point of -BBO and the created THz power in argon was likewise explored. -BBO with ideal shifting point and pre-planned thickness can all the while repay the time delay and spatial stroll off of the two-variety laser radiates, assuming the basic part in further developing the age proficiency of THz wave. This examination work accomplished a forward leap in the energy change proficiency of THz waves created by the two-variety femtosecond laser filamentation, which is of extraordinary importance for the investigation of extreme focus THz sources and the investigation of the connection between solid THz bar and materials.
More information: Zhiqiang Yu et al, 0.35% THz pulse conversion efficiency achieved by Ti:sapphire femtosecond laser filamentation in argon at 1 kHz repetition rate, Opto-Electronic Advances (2022). DOI: 10.29026/oea.2022.210065
