The list of currently available media for providing such a ring cavity 202 include {HEAD ~ electrical cable}, coaxial cable, reverberation lines, delay lines, {TAIL ~ fiber optical cable} and microwave cavities 
The list of currently available media for providing such a ring cavity 202 include { HEAD ~ electrical cable } , coaxial cable , reverberation lines , delay lines , { TAIL ~ fiber optical cable } and microwave cavities
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH