Apart from Leroy Jenkins' Solo Concert from 1976, I do not think that there are many solo violin albums that fall within the broad "jazz" genre. You could also argue that Polly Bradfield's "Solo Violin Improvisations" from 1979 is jazz. Now Polonia re-issued this album by Polish musician Zbigniew Seifert. Seifert was a classically trained violinist whose musical world opened when listening to Coltrane. He switched to sax shortly, then moved back to violin, trying to capture Coltrane's timeless expressivity and open esthetic. On this album, you can hear this Coltrane influence, together with a modern classical touches and even some European folk. His improvisations range from the very abstract to real rhythmic jazzy, from sad to joyful. On two tracks, he dubbed some additional violin, as a kind of background support, or even drone. Seifert died in 1979 at the age of 32 and he did not leave that many records. If you search for this record on internet, download links can be found all over the place.
PS - I got the additional information that Billy Bang released a solo violin album, "Commandments" (No More Records 1997), as did Malcolm Goldstein "Live In Fire In The Valley" (Eremite 1997). Thanks Pedro for the info!
Watch a rare video-taped recording of Seifert: