optical fibre 
noun
A thin flexible fibre with a glass core through which light signals can be sent with very little loss of strength.Such fibres might outperform normal optical fibres because light trapped in their hollow core travels through a tenuous gas, rather than a solid glass....
- In that technique, an optical fiber is used to transmit light from a specially coated lens.
- The light detected by the receiver is transmitted through an optical fibre to a computerised spectrum analyser.
- attention-getter
- attention-getting
- attention-grabber
- attention-grabbing
- attention-seeker
- attention-seeking
- attention span
- attentive
- attentively
- attentiveness
- attenuate
- attenuated
- attenuation
- attenuator
- atter
- attest
- attestable
- attestation
- attestor
- at that
- at the best of times
- at the buzzer
- at the coalface
- at the door
- at the double (on the double)