Thermography Using Liquid Crystals

Gleeson, Helen F.

doi:10.1002/9783527671403.hlc141

Cited by 2 publications

(1 citation statement)

References 178 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among them are customizable filters for multispectral and hyperspectral images, polarization monitoring devices for polarimetric images, and SLMs that provide a variety of visualization modes of health state parameters [ 12 , 13 , 14 ]. The potential of LC thermography of the skin was investigated to detect skin and breast cancer [ 15 , 16 ], as well as to diagnose thrombosis [ 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Helical Nanostructures of Ferroelectric Liquid Crystals as Fast Phase Retarders for Spectral Information Extraction Devices: A Comparison with the Nematic Liquid Crystal Phase Retarders

et al. 2021

View full text Add to dashboard Cite

Extraction of spectral information using liquid crystal (LC) retarders has recently become a topic of great interest because of its importance for creating hyper- and multispectral images in a compact and inexpensive way. However, this method of hyperspectral imaging requires thick LC-layer retarders (50 µm–100 µm and above) to obtain spectral modulation signals for reliable signal reconstruction. This makes the device extremely slow in the case of nematic LCs (NLCs), since the response time of NLCs increases proportionally to the square of the LC-layer thickness, which excludes fast dynamic processes monitoring. In this paper, we explore two approaches for solving the speed problem: the first is based on the use of faster nanospiral ferroelectric liquid crystals as an alternative to NLCs, and the second is based on using a passive multiband filter and focuses on multispectral extraction rather than hyperspectral. A detailed comparative study of nematic and ferroelectric devices is presented. The study is carried out using a 9-spectral bands passive spectral filter, covering the visible and near-infrared ranges. We propose the concept of multispectral rather than hyperspectral extraction, where a small number of wavelengths are sufficient for specific applications.

show abstract