At the end of Episode VI: ROTJ, Luke defiantly "hurls away" his lightsaber - according to both screenplay and novelization - before declaring "I am a Jedi, as my father was before me".
I have just re-watched the scene, and can't see anywhere where that lightsaber fell in any of the shots, nor do I see a single shot where Luke would pick up his lightsaber after the Emperor died.
Is there any canon information on what happened to that lightsaber? Did he retrieve it? Did he just build a new one and this one blew up together with Death Star 2?
NOTE: We know for sure that Vader's fell to the chasm below the walkway where Luke fought him, from both the screenplay and novelization. Since Luke's isn't mentioned to have fallen down, it may be presumed possible that it didn't.