Electronically tunable polarization-independent micro lens using polymer network twisted nematic liquid crystal

• US 7,408,601 B1
• Filed: 12/09/2005
• Issued: 08/05/2008
• Est. Priority Date: 06/23/2003
• Status: Expired due to Fees

• Current Assignee: University of Central Florida Research Foundation Inc. (State University System of Florida)
• Original Assignee: University of Central Florida (State University System of Florida)
• Inventors: Wu, Shin-Tson, Zhu, Xinyu, Ren, Hongwen, Huang, Yuhua
• Primary Examiner(s): Nelms; David C.
• Assistant Examiner(s): Chien; Lucy P
• Application Number:
  US11/298,118
• Time in Patent Office: 970 Days
• Field of Search: 349/200
• US Class Current: 349/95
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13345 Network or three-dimensional gels
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection
• CPC Class Codes: G02F 1/294 Variable focal length devices

Abstract

Inhomogeneous concentrated polymer network with approximately 90° twisted nematic liquid crystal (TN-LC) is used for fabricating lens and prisms. For forming a positive lens, the approximately 90° TN-LC polymer network concentration can gradually decrease from the center to the side edges. For forming a negative lens, the approximately 90° TN-LC polymer network concentration can gradually increase from the center to the side edges. The lens can be created by ultra violet (UV) light exposure to patterned photo masks. The lens can be tuned by applying voltage above the threshold voltage to the polymer network. The inhomogeneous 90° TN-LC polymer network can also be used in Fresnel lens and prisms. Applications of the invention can be used for micro lens, array, optical communication, micro-optics, adaptive optics and beam steering.

Claims

1. A method of fabricating an inhomogeneous layer of approximately 90°

TN-LC polymer network, wherein one of a negative and a positive lens is formed by using a photo mask with transparency that increases linearly from the center to the outer side edges of the negative lens and increases linearly from the outer side edges to the center of the positive lens.