Letters|3 Article(s)
Letters
All-liquid-crystal and full-visible-band tunable polarimetry
Guang-Yao Wang, Han Cao, Zheng-Hao Guo, Chun-Ting Xu... and Wei Hu|Show fewer author(s)
Polarization, the vector nature of electromagnetic waves, plays a vital role in optics. Polarization is characterized by the amplitude contrast and phase difference between two orthogonal polarization states. The present polarimeters usually perform a series of intensity measurements to carry out the polarization detection, making the process bulky and time-consuming. Thereby, compact and broadband-available polarimetry within a single snapshot is urgently demanded. We propose an all-liquid-crystal polarimeter for broadband polarization detection. It is cascaded by a q-plate and a polarization grating. The former is electrically tuned to meet the half-wave condition, whereas the latter is driven to deviate from this condition. After a polarized light passes through this device followed by a polarizer, its amplitude contrast and phase difference between orthogonal spins are read directly from the diffraction pattern. The intensity contrast between ±1st orders depicts the amplitude contrast, whereas the rotating angle of the dark split reveals the phase difference. The Stokes parameters can be calculated accordingly. The polarimeter works in a broad spectral range of 470 to 1100 nm. Through presetting a q-plate array, polarization imaging is demonstrated. It supplies an all-liquid-crystal and full-visible-band tunable Stokes polarimeter that significantly promotes advances in polarization optics. Polarization, the vector nature of electromagnetic waves, plays a vital role in optics. Polarization is characterized by the amplitude contrast and phase difference between two orthogonal polarization states. The present polarimeters usually perform a series of intensity measurements to carry out the polarization detection, making the process bulky and time-consuming. Thereby, compact and broadband-available polarimetry within a single snapshot is urgently demanded. We propose an all-liquid-crystal polarimeter for broadband polarization detection. It is cascaded by a q-plate and a polarization grating. The former is electrically tuned to meet the half-wave condition, whereas the latter is driven to deviate from this condition. After a polarized light passes through this device followed by a polarizer, its amplitude contrast and phase difference between orthogonal spins are read directly from the diffraction pattern. The intensity contrast between ±1st orders depicts the amplitude contrast, whereas the rotating angle of the dark split reveals the phase difference. The Stokes parameters can be calculated accordingly. The polarimeter works in a broad spectral range of 470 to 1100 nm. Through presetting a q-plate array, polarization imaging is demonstrated. It supplies an all-liquid-crystal and full-visible-band tunable Stokes polarimeter that significantly promotes advances in polarization optics.
Advanced Photonics Nexus
- Publication Date: Mar. 08, 2025
- Vol. 4, Issue 2, 025001 (2025)
High-speed free-space optical communication using standard fiber communication components without optical amplification
Hua-Ying Liu, Yao Zhang, Xiaoyi Liu, Luyi Sun... and Zhenda Xie|Show fewer author(s)
Free-space optical communication (FSO) can achieve fast, secure, and license-free communication without physical cables, providing a cost-effective, energy-efficient, and flexible solution when fiber connection is unavailable. To achieve FSO on demand, portable FSO devices are essential for flexible and fast deployment, where the key is achieving compact structure and plug-and-play operation. Here, we develop a miniaturized FSO system and realize 9.16 Gbps FSO in a 1 km link, using commercial single-mode-fiber-coupled optical transceiver modules without optical amplification. Fully automatic four-stage acquisition, pointing, and tracking systems are developed, which control the tracking error within 3 μrad, resulting in an average link loss of 13.7 dB. It is the key for removing optical amplification; hence FSO is achieved with direct use of commercial transceiver modules in a bidirectional way. Each FSO device is within an overall size of 45 cm × 40 cm × 35 cm, and 9.5 kg weight, with power consumption of ∼10 W. The optical link up to 4 km is tested with average loss of 18 dB, limited by the foggy test environment. With better weather conditions and optical amplification, longer FSO can be expected. Such a portable and automatic FSO system will produce massive applications of field-deployable high-speed wireless communication in the future. Free-space optical communication (FSO) can achieve fast, secure, and license-free communication without physical cables, providing a cost-effective, energy-efficient, and flexible solution when fiber connection is unavailable. To achieve FSO on demand, portable FSO devices are essential for flexible and fast deployment, where the key is achieving compact structure and plug-and-play operation. Here, we develop a miniaturized FSO system and realize 9.16 Gbps FSO in a 1 km link, using commercial single-mode-fiber-coupled optical transceiver modules without optical amplification. Fully automatic four-stage acquisition, pointing, and tracking systems are developed, which control the tracking error within 3 μrad, resulting in an average link loss of 13.7 dB. It is the key for removing optical amplification; hence FSO is achieved with direct use of commercial transceiver modules in a bidirectional way. Each FSO device is within an overall size of 45 cm × 40 cm × 35 cm, and 9.5 kg weight, with power consumption of ∼10 W. The optical link up to 4 km is tested with average loss of 18 dB, limited by the foggy test environment. With better weather conditions and optical amplification, longer FSO can be expected. Such a portable and automatic FSO system will produce massive applications of field-deployable high-speed wireless communication in the future.
Advanced Photonics Nexus
- Publication Date: Oct. 14, 2023
- Vol. 2, Issue 6, 065001 (2023)
Vortex-induced quasi-shear polaritons|Article Video
Shuwen Xue, Yali Zeng, Sicen Tao, Tao Hou... and Huanyang Chen|Show fewer author(s)
Hyperbolic shear polaritons (HShPs) emerge with widespread attention as a class of polariton modes with broken symmetry due to shear lattices. We find a mechanism of generating quasi-HShPs(q-HShPs). When utilizing vortex waves as excitation sources of hyperbolic materials without off-diagonal elements, q-HShPs will appear. In addition, these asymmetric q-HShPs can be recovered as symmetric modes away from the source, with a critical transition mode between the left-skewed and right-skewed q-HShPs, via tuning the magnitude of the off-diagonal imaginary component and controlling the topological charge of the vortex source. It is worth mentioning that we explore the influence of parity of topological charges on the field distribution and demonstrate these exotic phenomena from numerical and analytical perspectives. Our results will promote opportunities for both q-HShPs and vortex waves, widening the horizon for various hyperbolic materials based on vortex sources and offering a degree of freedom to control various kinds of polaritons. Hyperbolic shear polaritons (HShPs) emerge with widespread attention as a class of polariton modes with broken symmetry due to shear lattices. We find a mechanism of generating quasi-HShPs(q-HShPs). When utilizing vortex waves as excitation sources of hyperbolic materials without off-diagonal elements, q-HShPs will appear. In addition, these asymmetric q-HShPs can be recovered as symmetric modes away from the source, with a critical transition mode between the left-skewed and right-skewed q-HShPs, via tuning the magnitude of the off-diagonal imaginary component and controlling the topological charge of the vortex source. It is worth mentioning that we explore the influence of parity of topological charges on the field distribution and demonstrate these exotic phenomena from numerical and analytical perspectives. Our results will promote opportunities for both q-HShPs and vortex waves, widening the horizon for various hyperbolic materials based on vortex sources and offering a degree of freedom to control various kinds of polaritons.
Advanced Photonics Nexus
- Publication Date: Jan. 03, 2023
- Vol. 2, Issue 1, 015001 (2023)
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