Design and fabrication of a simple and cost-effective optical flow meter using liquid crystals and textile grid.

The measurement of airflow velocity is crucial in various fields, and several sensing approaches have been developed for detecting airflow, including optical fiber-based flowmeters. However, these sensors often require complex fabrication processes and precise optical alignment. In this paper, a simpler and more cost-effective approach has been used to measure air flow rate by utilizing the birefringence property of liquid crystals (LCs).

Optimizing liquid crystal cell thickness in electro-optical Fresnel lenses through theoretical calculations and experimental validation.

Tunable liquid crystal (LC) lenses have gained significant attention in recent decades due to their lightweight, low cost, and versatility in applications such as augmented reality, ophthalmic devices, and astronomy. Although various structures have been proposed to improve the performance of LC lenses, the thickness of the LC cell is a critical design parameter that is often reported without sufficient justification. While increasing the cell thickness can lead to a shorter focal length, it also results in higher material response times and light scattering.

Reduction of solar infrared heating by using highly transparent thin films based on organic chiral nematic liquid crystal polymer.

This paper demonstrates a thin and transparent reflector film for the near infrared, based on chiral nematic liquid crystal (CLC) polymers. Two films reflect almost 50% of unpolarized incident light from 730 to 820 nm and from 880 to 1030 nm, while remaining completely transparent in the visible region with transmittance >90. An efficient window uses the combination of two reflectors.

Fabrication of a spatially tunable band reject filter with a very wide tunability range based on a chiral nematic liquid crystal polymer.

A thin, waterproof, and stable spatially tunable band reject filter is fabricated based on a chiral nematic liquid crystal polymer. The fabrication method for this filter is new, to the best of our knowledge, and straightforward. The photonic bandgap (PBG) of the proposed filter can be tuned from 350 nm to 760 nm by a mechanical movement of 6.