The actor admitted he's unsure if another Torchwood series will be commissioned, but thinks that there's much more of Captain Jack's story to tell.
He told Entertainment Wise: "I'm happy with what the writers write. I like the aspect of that particular job - I'm not a producer, I'm not a writer, I come in and I get the scripts and I do the job, and I bring the character to life and that kind of brings a bit of the pressure off!
"But I think I'd love to see Jack time travel a little more, and I love going back in time to Jack's past. I think that's also nice to explore."
Barrowman also explained that he enjoys playing Captain Jack because the Torchwood leader doesn't fit the traditional mould of sci-fi heroes.
"He's not a typical type of hero that you would see in a comic book or in a TV show, and that's what I love about him," he commented. "That's what makes him fun to play. Also he's a little bit naughty and he speaks his mind, and he's got conviction with everything he does."
Barrowman previously declared that he'd love to return to Doctor Who for the show's 50th anniversary in 2013.
> John Barrowman announces Very Best Of collection
> John Barrowman: 'I've never slept with a Doctor Who groupie'
Watch John Barrowman's 'All Out of Love' music video below: