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Proceedings Paper

Nonlinear femtosecond pulse compression in cholesteric liquid crystals (Conference Presentation)
Author(s): Yikun Liu; Jianying Zhou; Tsung-Hsien Lin; Iam-Choon Khoo

Paper Abstract

Liquid crystals materials have the advantage of having a large nonlinear coefficient, but the response time is slow, normally up to several minisecond. This makes it is hard to apply in ultra fast optical devices. Recently, fentosecond (fs) nonlinear effect in choleteric liquid crystals is reported, nonlinear coefficient in the scale of 10−12 cm2∕W is achieved. Base on this effect, in this work, fentosecond pulse compression technique in a miniature choleteric liquid crystal is demonstrated1,2. Cholesteric liquid crystals (CLC) is a kind of 1-dimensional phontonic structure with helical periodic. In a 10 μm thick CLC, femtosecond pulse with 100 fs is compressed to about 50 fs. CLC sample in planar texture with 500μm thick cell gap is further fabricated. In this sample, femtosecond pulse with 847 fs can be compressed to 286 fs. Due to the strong dispersion at the edge of photonic band gap, femtosecond pulse stretching and compensation can be achieve. In this experiment, laser pulse with duration 90 fs is stretched to above 2 picosecond in the first CLC sample and re-compressed to 120 fs in the second sample. Such technique might be applied in chirp pulse amplification. In conclusion, we report ultra fast nonlinear effect in cholesteric liquid crystals. Due to the strong dispersion and nonlinearity of CLC, femtosecond pulse manipulating devices can be achieved in the scale of micrometer.

Paper Details

Date Published: 2 November 2016
PDF: 1 pages
Proc. SPIE 9940, Liquid Crystals XX, 99400I (2 November 2016); doi: 10.1117/12.2236778
Show Author Affiliations
Yikun Liu, Sun Yat-Sen Univ. (China)
Jianying Zhou, Sun Yat-Sen Univ. (China)
Tsung-Hsien Lin, National Sun Yat-Sen Univ. (Taiwan)
Iam-Choon Khoo, The Pennsylvania State Univ. (United States)


Published in SPIE Proceedings Vol. 9940:
Liquid Crystals XX
Iam Choon Khoo, Editor(s)

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