Method of implementation of all optical tri-state logic in frequency encoded format using non-linear material

All optical signal processing has capability of handling huge amount of data. This has become possible by the use of multi-valued logic in place of binary logic. In this communication a frequency encoded tri-state logic gates NOT, AND and NAND are proposed for the first time using difference frequency generation in non-linear materials. The operating principle of the logic gate is the difference frequency generation which is purely an optical phenomenon where no electrical energy is required. So it has greater speed of operation and uses less power. The state of information is represented by three different frequency conditions which have due advantage compared to other kind of encoding technique commonly used.