Electrically tunable polarisation-independent blue-phase liquid crystal binary phase grating via phase-separated composite films

ABSTRACT

A simple method for fabricating polarisation-independent blue-phase liquid crystal phase grating is demonstrated by implementing photopolymerisation-induced phase separation through a binary photomask. The dynamic focusing property of the proposed liquid crystal grating is independent of the polarisation state of incident light. The efficiency of various diffraction orders for the phase grating was measured as a function of the applied voltage. Experimental results show that the maximum diffraction efficiency reaches 36% for the ±1 order, which approaches the theoretical limit ~41%. The measured rise time is 1.4 ms and fall time is 2.2 ms. Such a tunable grating has great potential for photonic applications.

Graphical Abstract

KEYWORDS:

• Blue-phase liquid crystal
• phase grating
• diffraction
• photopolymerisation-induced phase separation

Acknowledgements

This research was supported by grants from the Scientific and Technological Research Council of Turkey (TUBITAK) to N. Avci and the Ministry of Science and Technology of The Republic of China, Taiwan (MOST 104-2918-I-239-001) to S.-J. Hwang.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by grants from the Scientific and Technological Research Council of Turkey (TUBITAK) to N. Avci and the Ministry of Science and Technology of the Republic of China, Taiwan (MOST 104-2918-I-239-001) to S.-J. Hwang.