Sharman-Lowe made three appearances for Burton Albion's first-team before he signed for Chelsea in 2021.
He spent last season on loan with Bromley in the National League.
Rovers goalkeeping coach Kyle Letheren said: “We identified Ted as one of our main targets and I’m delighted we’ve been able to bring him to the football club.
“As our fanbase are aware, we are a possession-based team and it was fundamental we brought in a goalkeeper that was strong in possession. Ted is exactly that.
“He is very highly-rated at Chelsea and comes to us with some really strong recommendations.
“After doing my home work on Ted, I feel we have one of the best young goalkeepers in the country. He’s a great size at 6ft4in and a really good shot stopper
“I feel like we are perfect fit for Ted and I’m excited to be working with another talented goalkeeper on a daily basis.”