Intellectual Property Office

Non-Confidential Disclosures

“Liquid Crystal Fiber Array for Optical Limiting of Laser Pulses and for Eye/Sensor Protection”

PSU Inv. Disc. No 94-1314

Keywords:

Optical limiter

Inventors:

I.C. Khoo

Links:

US Patent 5,589,101
http://www.ipo.psu.edu

Background:

There is a need for devices which protect both the eyes and sensitive optical instruments against damage from an incident laser beam. However, liquid crystal nonlinearity thresholds exhibited by bulk thin films and/or liquid crystal cells are too high to provide a satisfactory optical limiting effect when subjected to a high intensity optical beam. As a result, liquid crystal geometries have not heretofore been used for optical protection applications which must respond in nanosecond time intervals.

Invention description:

A protective liquid crystal fiber array includes a body having a plurality of capillary passages extending between incident and transmitting faces. A liquid phase, liquid crystal material is positioned in each of the capillaries and optically transparent closures are positioned on the incident and transmitting faces to retain the liquid phase liquid crystal material within the capillaries. The liquid crystal material is substantially transparent at low levels of optical energy, which at high levels of incident optical energy, exhibits an optical limiting effect as a result of a negative change in its refractive index. The change in refractive index is enhanced as a result of thermal density effects due to the restriction of the incident optical energy within the diameter of one or more capillaries.

Advantages:

• A device which protects against incident high intensity optical beams
  
• An optical protection device which requires no external control instrumentality
  
• Device is physically small and reacts to an incident beam in a nanosecond time interval
  

Contact:

Bradley A. Swope
Sr. Technology Licensing Officer
Intellectual Property Office
113 Technology Center
The Pennsylvania State Univ.
University Park, PA 16802-7000
Phone: (814) 863-5987
Fax: (814) 865-3591
E-mail:bradswope@psu.edu