Tunable-focus liquid crystal Fresnel zone lens based on harmonic diffraction
We propose and demonstrate a tunable-focus liquid crystal Fresnel zone lens (TLCFZL) based on harmonic diffraction. The physical mechanism of the focus tuning is based on a multi-order diffraction process using a shallow surface relief type harmonic diffractive structure with uniform electrodes whic...
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Veröffentlicht in: | Applied physics letters 2012-11, Vol.101 (22) |
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Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
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Online-Zugang: | Volltext |
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Zusammenfassung: | We propose and demonstrate a tunable-focus liquid crystal Fresnel zone lens (TLCFZL) based on harmonic diffraction. The physical mechanism of the focus tuning is based on a multi-order diffraction process using a shallow surface relief type harmonic diffractive structure with uniform electrodes which results in significantly reduced fabrication complexity and excellent electro-optic performances. A rapid fabrication process including imprinting technique is studied, from which a high performance TLCFZL with three switchable focus lengths and high diffraction efficiency (about 70%) is fabricated. Focusing and imaging properties of the TFLCFZL are tested. The highest resolution of the lens reaches 22.6 lp/mm with low operating voltage of less than 7.2 Vrm and response time of ∼200 ms. |
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ISSN: | 0003-6951 1077-3118 |
DOI: | 10.1063/1.4769090 |