Who can imagine science fiction without the concepts of faster than light travel/warp speed, stasis/hyper-sleep, teleportation, time travel, laser/ray guns, AI/robots/androids, etc.
Of course not all fictional Sci-Fi worlds have all of these elements present but they have become generally accepted storytelling conventions to the point of becoming mundane and therefore almost invisible. All are also arguably now rather simple mediocre plot device ‘props’? Very infrequently does one encounter anything truly memorable any more [like ‘bullet time’ as popularised in The Matrix].
Some poetic ideas though wheedle their way into your consciousness to the extent that you feel deprived by their absence in the wider field of speculative fiction,
For me one such idea is the floating ‘islands’ beloved of Roger Dean [a similar concept makes a brief appearance in Cameron’s Avatar – Dean is suing] of which he has been trying to make into a film version for 30 years. Another is the idea of ‘slow glass’ as most prominently showcased by Bob Shaw’s 1966 Light of other days and several subsequent stories.
It is difficult to pinpoint the origin of any memorable fictional idea, especially as “good writers borrow, great writers steal”, but perhaps the key to creating stand-out fiction is not necessarily finding that original/unique idea [if that is at all possible] but rather is to somehow string together a series of defining/iconic moments?