PIER | PIER Journals

2023-05-25

PIER

Vol. 177, 43-51, 2023

download: 30

Broad-Tuning, Dichroic Metagrating Fabry-Perot Filter Based on Liquid Crystal for Spectral Imaging

Tingbiao Guo Zijian Lin Xinan Xu Zhi Zhang Xiao Chen Nan He Guoqing Wang Yi Jin Julian Evans Sailing He

Dynamic structural color can empower devices with additional functions like spectrum and polarization detection beyond display or imaging. However, present methods suffer from narrow tuning ranges, low throughput, or bulky volumes. In this work, a tunable filter composed of a dichroic metagrating Fabry-Perot cavity and liquid crystal (LC) material is proposed and investigated. By modulating the polarization of the incident light with the LC, the color response can change from blue to green and deep red due to the `mode jumping' effect, with a tuning range of around 300 nm. Besides, we experimentally demonstrate the use of this device as a spectral imager in the visible range. Experimental results show that spectral resolvability can be around 10 nm, with the largest peak wavelength in accuracy of ~5 nm. This approach shows superior performance over traditional liquid crystal tunable filters in low light conditions and indicates the potential of dynamic structural color for miniaturized spectroscopic applications.

Broad-tuning, Dichroic Metagrating Fabry-Perot Filter Based on Liquid Crystal for Spectral Imaging

2023-04-04

PIER

Vol. 177, 33-42, 2023

doi:10.2528/PIER22112703

download: 90

Systemically Delivered, Deep-Tissue Nanoscopic Light Sources

Xiang Wu Fan Yang Sa Cai Guosong Hong

Light is widely used in life science in both controlling and observing biological processes, yet a long-standing challenge of using light inside the tissue lies in the limited penetration depth of visible light. In the past decade, many in vivo light delivery methods using photonics and materials science tools have been developed, with recent demonstrations of non-invasive, deep-tissue light sources based on systemically delivered luminescent nanomaterials. In this perspective, we provide an overview for the principles of intravital nanoscopic light sources and discuss their advantages over existing methods for in vivo light delivery. We then highlight their recent applications in optogenetics neuromodulation and fluorescent imaging in live animals. We also present an outlook section about the feasibility of combining these non-invasive light sources with other modalities to expand the utilities of light in biology.

Systemically Delivered, Deep-tissue Nanoscopic Light Sources

2023-03-23

PIER

Vol. 177, 21-32, 2023

doi:10.2528/PIER23012902

download: 34

Highly Sensitive Temperature Sensing via Photonic Spin Hall Effect

Shuaijie Yuan Jin Yang Yong Wang Yu Chen Xinxing Zhou

In this work, we propose a highly sensitive temperature sensor based on photonic spin Hall effect (PSHE). We find that, by involving the liquid crystal (LC) material, the spin spatial and angular shifts in PSHE are very sensitive to the tiny perturbation of temperature when the incident angle of light beam is near the Brewster and critical angles. Importantly, the phase transition from liquid crystal state to liquid state across the clearing point (CP) will lead to the transition of strong spin-orbit interaction to the weak one. During this process, we reveal that the sensitivity of our designed temperature sensor can reach a giant value with 8.27 cm/K which is one order of magnitude improvement compared with the previous Goos-Hänchen effect-based temperature sensor. This work provides an effective method for precisely determining the position of CP and actively manipulating the spin-orbit interaction.

Highly Sensitive Temperature Sensing via Photonic Spin Hall Effect

2023-02-13

PIER

Vol. 177, 1-20, 2023

doi:10.2528/PIER22101202

download: 24

Topological Edge Modes in One-Dimensional Photonic Artificial Structures (Invited)

Jiajun Zheng Zhiwei Guo Yong Sun Haitao Jiang Yunhui Li Hong Chen

In recent years, topological states in photonic artificial structures have attracted great attention due to their robustness against certain disorders and perturbations. To readily understand the underlying principles, topological edge modes in one-dimensional (1D) system have been widely investigated, which bring aboutthe discovery of novel optical phenomena and devices. In this article, we review our recent advances in topological edge modes. We introduce the connection between topological orders and effective electromagnetic parameters of photonic artificial structures in band gaps, discuss experimental demonstration of robust topological modes and their potential applications in wireless power transfer, sensing and field of optics, and give a brief introduction of future opportunities in 1D topological photonics.