I haven't heard Regina Carter in a long time, but if I remember correctly, she has an avant garde approach to her playing. If you are interested in the avant garde violinists then I'm pretty sure that you will like the artist/albums that I am listing.
These are albums that I have and listen to, not a google search. My list is my opinion.
Mat Maneri's album called Blue Decco is great album. I list it first because its my favorite album on this list.
Billy Bang can be heard on William Parker's album Scrapbook. I believe that Regina Carter has a very similar sound to Billy Bang, I can't remember for sure.
Leroy Jenkins is a legend of the avant garde violin. My favorite album to hear him on is The Creative Construction Company, Volume 2. It's only available on vinyl record. A great band on that album, including Anthony Braxton and Richard Davis.
Also try Alice Coltrane's album called Universal Consciousness. Another great Alice Coltrane album.
As the above answer states, John Blake is another one to seek out. I only know him from his playing on two James Newton albums, The African Flower and a self titled album. Both of these albums are great, in my opinion, and both are only available on vinyl record, as far as I know. ONe of my favorite songs of all time is on the African Flower album. Its called Fleurette Africaine, John Blake is AMAZING on that song, and the rest of the album.