Polarization|4 Article(s)
Highly efficient generation of arbitrary vector beams with tunable polarization, phase, and amplitude
Sheng Liu, Shuxia Qi, Yi Zhang, Peng Li, Dongjing Wu, Lei Han, and Jianlin Zhao
We propose an efficient and robust method to generate tunable vector beams by employing a single phase-type spatial light modulator (SLM). With this method, a linearly polarized Gaussian beam can be converted into a vector beam with arbitrarily controllable polarization state, phase, and amplitude. The energy loss during the conversion is greatly reduced and depends mainly on the reflectivity of the SLM. We experimentally demonstrate that conversion efficiency of about 47% is achieved by using an SLM with reflectivity of 62%. Several typical vector beams, including cylindrical vector beams, vector beams on higher order Poincaré spheres, and arbitrary vector beams attached with phases and with tunable amplitude, are generated and verified experimentally. This method is also expected to create high-power vector beams and play important roles in optical fabrication and light trapping.
Photonics Research
  • Publication Date: Mar. 01, 2018
  • Vol. 6, Issue 4, 04000228 (2018)
Experimental realization to efficiently sort vector beams by polarization topological charge via Pancharatnam–Berry phase modulation
Shuiqin Zheng, Ying Li, Qinggang Lin, Xuanke Zeng, Guoliang Zheng, Yi Cai, Zhenkuan Chen, Shixiang Xu, and Dianyuan Fan
This paper reports the experimental realization of efficiently sorting vector beams by polarization topological charge (PTC). The PTC of a vector beam can be defined as the repetition number of polarization state change along the azimuthal axis, while its sign stands for the rotating direction of the polarization. Here, a couple of liquid crystal Pancharatnam–Berry optical elements (PBOEs) have been used to introduce conjugated spatial phase modulations for two orthogonal circular polarization states. Applying these PBOEs in a 4-f optical system, our experiments show the setup can work for PTC sorting with a separation efficiency of more than 58%. This work provides an effective way to decode information from different PTCs, which may be interesting in many fields, especially in optical communication.
Photonics Research
  • Publication Date: Apr. 18, 2018
  • Vol. 6, Issue 5, 05000385 (2018)
Optically spatial information selection with hybridly polarized beam in atomic vapor
Jinwen Wang, Xin Yang, Yunke Li, Yun Chen, Mingtao Cao, Dong Wei, Hong Gao, and Fuli Li
Vector beams with spatially variant polarization have attracted much attention in recent years, with potential applications in both classical optics and quantum optics. In this work, we study a polarization selection of spatial intensity distribution by utilizing a hybridly polarized beam as a coupling beam and a circularly polarized beam as a probe beam in Rb87 atom vapor. We experimentally observe that the spatial intensity distribution of the probe beam after passing through atoms can be modulated by the hybridly polarized beam due to the optical pumping effect. Then, the information loaded in the probe beam can be designedly filtrated by an atomic system with a high extinction ratio. A detailed process of the optical pumping effect in our configurations and the corresponding absorption spectra are presented to interpret our experimental results, which can be used for the spatial optical information locally extracted based on an atomic system, which has potential applications in quantum communication and computation.
Photonics Research
  • Publication Date: Apr. 23, 2018
  • Vol. 6, Issue 5, 05000451 (2018)
Wavelength-switchable vortex beams based on a polarization-dependent microknot resonator
Jinqiu Zheng, Ao Yang, Teng Wang, Xianglong Zeng, Ning Cao, Mei Liu, Fufei Pang, and Tingyun Wang
We experimentally demonstrated a method of generating continuously wavelength-switchable optical vortex beams (OVBs) in an all-fiber laser. A polarization-dependent microknot resonator (MKR) functions as comb filter and accounts for the narrow linewidth (0.018 nm) of multiwavelength channels. The wavelength interval corresponds to the free spectral range of the MKR. We exploit a fused SMF–FMF (single mode fiber–few mode fiber) mode coupler to obtain broadband mode conversion and successfully achieve multiwavelength switchable OVBs. As far as we know, this is the first report about identical multiwavelength vortex beams with topological charges of ±1. It has been verified that each channel of the vortex beams preserves the same orbital angular momentum (OAM) properties through their clear spiral interferograms. Multiwavelength vortex beams with identical OAM properties are desirable for multiplexing, exchanging, and routing to further improve the capacity of optical fiber transmission.
Photonics Research
  • Publication Date: Apr. 18, 2018
  • Vol. 6, Issue 5, 05000396 (2018)