About: http://webisa.webdatacommons.org/340940815

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Technical Background [0004] In optical communication systems, messages are transmitted by electromagnetic carrier waves at optical frequencies that are generated by such sources as lasers and light-emitting diodes.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com