John Randle, of Polperro Way, was also said to have repeatedly contacted his victim, threatened to blow up her house and stab her in the stomach.
Randle was arrested on September 2 last year after a report of a sex attack was made to the police.
He pleaded guilty at Nottingham Crown Court to sexual assault and harassing with fear of violence.
Det Con Barry Haines, of the police, said: “Sexual abuse and violence have no place in our county, and we will investigate reports made to us.
“As a force, we are committed to tackling abuse in all its forms. If you are a victim, please contact us on 101.”