Device and Method for Producing Optically-Controlled Incremental Time Delays
Summary
Generating precise and reliable true time delays (TTDs) is of paramount importance for phased array radars and a host of other applications. True time delay avoids beam squint in wideband antenna systems. Researchers at The Ohio State University have developed a free-space optical TTD device that can provide many bits of delay (more than 15 bits) for hundreds of antenna elements in ultra-compact form (half a cubic foot) with delays varying from femtoseconds to tens of nanoseconds. The invention uses a single MEMS chip, free space for massive overlapping of beam space, and a handful of mirrors. A programmable tapped delay line has many other uses, including optical correlation, optical matched filtering, optical signal processing, optical code-division multiple access coding and decoding, photonic analog-to-digital conversion, and optical communications performance monitoring. A variation of the device can also be used for optical interconnections and routers. Electronically implementing TTDs is generally impractical because of the need for many long lengths of strip line, waveguides, or coaxial cable, which are expensive, bulky, and temperature sensitive. Since long path lengths are relatively easy to obtain optically, optical TTD systems have been developed, either using fibers or free-space paths, but these existing systems are expensive and bulky due to the use of multiple optical switches. Researchers at The Ohio State University have developed a free-space optical TTD device that uses only one optical switch or spatial light modulator for the entire system instead of one or more switches for each bit, as in previous systems. Furthermore, the device avoids beam-spreading problems that may be present in other free-space systems by using a multiple-pass optical cell with refocusing mirrors. As a result, the device is more inexpensive, compact, and temperature insensitive than existing devices.
Main Advantages of Technical Approach
- Uses only one optical switch or spatial light modulator
- Ultra-compact form factor
- Small component count
Market Potential
- Optical multiplexing/demultiplexing applications
- Optical routing and switching
- Phased array radars
- Optical signal processing
- Optical performance monitoring
Inventor(s)
Betty Lise AndersonStuart Collins
Intellectual Property Status
US Patent #: 6,388,815 6,525,889Contact Information
Demian Phillipsphillips.631@osu.edu | 614-688-5744
Technology Licensing & Commercialization
The Ohio State University
1216 Kinnear Road
Columbus, OH 43212-1154
