Optical carrier synthesis in coherent lightwave systems

The requirements for the optical sources for future coherent lightwave systems employing phase modulation techniques have been identified. A technique for generating many narrow linewidth optical channels has been proposed using an optical frequency-locked loop. This is seen as an interim solution until inexpensive moderately narrow linewidth monolithic lasers can be acquired. Then the option of designing a narrowband optical phase-locked loop with the possibility of line-narrowing and precise frequency offsets becomes available. Finally, the use of this optical frequency synthesiser has been considered in the design of a high capacity optical network