Abstract

We demonstrate wavelength-independent optical limiting based on colloidal phase transitions induced by the dielectrophoretic force from focused electromagnetic radiation. The focused radiation acts as an optical trap that increases the particle density. The increased density then leads to a colloidal gas-solid phase transition and an aggregate that effectively blocks the incoming radiation when it passes a threshold power. The process is reversible, with the colloidal particles returning to a homogenous distribution after the incoming radiation is removed. We demonstrate the effect using polystyrene nanoparticles mixed with pluronics and polyethylene glycol polymers in low-concentration KCl salt solutions. We observe the light-induced phase separation under confocal fluorescent microscope, and we provide a proof-of-principle demonstration of optical limiting using a 100 μm thick colloid cell.

© 2019 Optical Society of America

Optomechanical properties of optically self-arranged colloidal waveguides

Oto Brzobohatý, Lukáš Chvátal, and Pavel Zemánek
Opt. Lett. 44(3) 707-710 (2019)

Optical trapping below the diffraction limit with a tunable beam waist using super-oscillating beams

Harel Nagar, Tamir Admon, Doron Goldman, Amir Eyal, and Yael Roichman
Opt. Lett. 44(10) 2430-2433 (2019)

Colloidal plasmonic DNA-origami with photo-switchable chirality in liquid crystals

Qingkun Liu, Anton Kuzyk, Masayuki Endo, and Ivan I. Smalyukh
Opt. Lett. 44(11) 2831-2834 (2019)

Ultra-broadband fiber mode converter based on apodized phase-shifted long-period gratings

Yunhe Zhao, Zuyao Liu, Yunqi Liu, Chengbo Mou, Tingyun Wang, and Yongsheng Yang
Opt. Lett. 44(24) 5905-5908 (2019)

Dynamically tunable bowtie nanoantennas based on the phase transition of vanadium dioxide

Fang-Zhou Shu, Li-Heng Zhang, Jia-Nan Wang, Ru-Wen Peng, Ren-Hao Fan, Dong-Xiang Qi, and Mu Wang
Opt. Lett. 44(11) 2752-2755 (2019)