According to a paper published in ACS Applied Electronic Materials recently, a collaborated research group of HFIPS successfully developed an active terahertz phase modulator of NdGaO 3 (NGO) single crystals which were appropriate candidate for the THz phase modulator.
Finding appropriate materials to shape the terahertz (THz) wave is not only highly desired, but also a challenge that limits the engineering application of terahertz technology.
In this research, scientists found that NdGaO 3 crystals showed distinct terahertz phase shifts. When the temperature of NGO single crystals increased from 100 to 400 K, the THz phase shift would reach ～94°.
In addition, the terahertz phase shift of the NGO crystal was sensitive to the crystal orientation. Phase shifts for each crystal orientation showed a linearly proportional relationship.
With the help of optical control, the team achieved active modulation of the terahertz phase: the laser illumination could efficiently caused a noticeable terahertz shift. Terahertz shift～ 78° with good manipulation stability could be achieved with 20 J/cm 2 light fluence. By changing the light fluence, the multi-state terahertz phase shift can be achieved.
Their sensitivity, and stability of the NGO crystals were expected to have a great technological impact and offer prospects for their applications in THz optics, according to the team.
ACS Applied Electronic Materials
30-Nov-2022