Researchers from the Institute of Aerospace Information of the Chinese Academy of Sciences, along with colleagues from the University of Nanjing, have made significant progress in the field of optics and photonics by developing a new method for modulating the polarization of Terahertz (ThZ) waves. These waves, located between the microwave and infrared ranges of the electromagnetic spectrum, have been a subject of active study for the past two decades. The findings of their research have been published in the journal Optica.
Polarization, which refers to the orientation of light waves, plays a crucial role in various modern technologies, from wireless communications to biomedical imaging. Controlling the polarization of waves has been a challenging task due to the unique characteristics of ThZ waves, including their long wavelength and wide frequency range.
To overcome these challenges, the scientists developed an innovative device known as a phase-compensated mirror with full internal reflective capacity (PCMT). By optimizing key parameters such as the distance between the mirror and the prism, as well as the double radiation of the liquid crystal, the researchers achieved precise control over phase and polarization across a broad frequency range with minimal intensity loss.
The PCMT device has demonstrated the capability to generate and switch between orthogonal linear polarizations, as well as left and right circular polarizations, within the frequency range of 1.6 to 3.4 Thuz. It offers exceptional polarization degrees, with linear and circular polarization indicators exceeding 0.996. Moreover, the device allows for the creation of arbitrary polarization states at any central frequency with a relative bandwidth of over 90%.
“Our work shows that Thz waves, once considered challenging to control, can now be precisely manipulated and directed,” stated Professor Chen Suezuan from the Institute of Aerospace Information. This breakthrough has the potential to revolutionize industries reliant on polarization technologies, such as communications, sensing, and materials research.