Chinese researchers achieve breakthrough in terahertz wave study

BEIJING -- A Chinese research team has developed a novel terahertz wave polarization modulator that can be used in multiple fields such as high-speed wireless communication, the Chinese Academy of Sciences' Aerospace Information Research Institute said on Wednesday.

The device can dynamically and precisely control the polarization state of terahertz waves, and is expected to accelerate the application of terahertz waves in next-generation wireless communication and the non-destructive examination of cultural relics, said the institute.

The study was completed by researchers from the institute and Nanjing University. Its results have been published in the international academic journal Optica.

Terahertz waves, which fall within the frequency range of 0.1 to 10 terahertz, are located between microwaves and infrared waves on the electromagnetic spectrum. They are characterized by their large bandwidth and strong penetration capabilities, making their potential applications in next-generation wireless communication, material testing and biomedicine highly promising.

"Accurate control of the polarization state of terahertz waves is crucial for their application in the aforementioned fields, but it is extremely challenging," said Chen Xuequan, a researcher at the Aerospace Information Research Institute. Due to their large bandwidth and wavelengths that are nearly three orders of magnitude longer than visible light, terahertz waves place very high demands on the materials and structures of polarization modulators.

In this study, the research team overcame these challenges by adjusting two key parameters of the polarization modulator: the distance between the metal mirror and prism, and the birefringence of liquid crystals. Compared with other terahertz wave polarization modulators, the newly developed modulator shows significant improvements in multifunctionality, wide operating bandwidth and high-control precision. The device can generate any desired polarization state of terahertz waves.

"This achievement can meet the needs of such applications as material property research and quality monitoring in bio-pharmaceuticals, and it can also reduce transmission losses and increase data throughput in high-speed communication," Chen said.