Fibre optic microwave filters

Demonstrates that the medium of fibre optics is a suitable one with which to implement microwave filters. Although such filters have not yet begun to approach their inherent Q-values of order 10⁵, their rich harmonic response could be exploited to enhance the Q of more conventional filters. An attractive aspect of fibre optic filters is their amenity to electrical programmability. In many respects they are more suitable for this purpose than their SAW counterparts. Another theme of this paper is the message that fibre optic filters are complementary to electrical components rather than competitive with them. Concerning their frequency range, the devices described here are certainly capable of operation up to say 10-20 GHz