Tunable liquid crystal-resonant grating filters using superimposed grating structures fabricated by nanoimprint lithography

• Published in: The 17th Annual Meeting of the IEEELasers and Electro-Optics Society, 2004. LEOS 2004 Vol. 1; pp. 298 - 299 Vol.1
• Main Authors: Chang, A.S.P., Morton, K.J., Murphy, P., Hua Tan, Wei Wu, Chou, S.Y.
• Format: Conference Proceeding
• Language: English
• Published: Piscataway NJ IEEE 2004
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Gratings; Liquid crystals; Microelectronic fabrication (materials and surfaces technology); Nanolithography; Optical filters; Optical refraction; Optical surface waves; Optical variables control; Optical waveguides; Resonance; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Tuning; Tunable circuit; Microelectronic fabrication; Experimental study; Nanolithography; Liquid crystals
• ISBN: 0780385578; 9780780385573
• DOI: 10.1109/LEOS.2004.1363229

Demonstration of superimposing a short-pitch gratings for aligning liquid crystals onto a larger-pitch subwavelength resonant grating (SRG) is presented, to achieve superior liquid crystal alignment, which leads to drastically improved tuning filter performance and tuning range. The tunable SRG needs a 1 /spl mu/m pitch gratings for the desired filter resonance frequency, which is in the infrared, and a-shallower gratings with a pitch between 200 nm to 400 nm for aligning liquid crystal, which is used for tuning the resonance frequency of the filter. A tuning range of 21 nm has been achieved.