New Jersey : An Indian American student convicted of spying on his gay roommate with his webcam doesn't deserve to be locked up with "rapists and murderers", a New Jersey judge said Wednesday.

"I can't find it in me to remand this gentleman to a state prison that houses rapists and murderers," judge Glenn Berman said as Ravi, 20, appeared in state court to officially say he'll surrender to jailers Thursday to begin his 30-day sentence.

"I'll stand on my belief that his conduct was wrong but not motivated by hate. I don't think it was motivated by hatred and I'll stand on that," he said referring to criticism of his light sentence for Ravi.

"The interest of justice justified what I did, I only have to look at my (e-mail) inbox that people disagree," Berman said.

Ravi, who had Tuesday apologised for his "insensitive, immature, stupid and childish" actions also waived his right to any double jeopardy claim while the Middlesex County prosecutors appeal the sentence.

Speaking in a brief hearing before Berman, Ravi said he understood that if the appellate division decided on a more severe sentence, he wouldn't be able to claim he had already served his time.

He also acknowledged that if his conviction is set aside, he could not get back the jail time he had served.

In March, a jury found Ravi guilty of bias intimidation, invasion of privacy and tampering counts in the spying case over his roommate, Tyler Clementi, who leaped to his death from the George Washington Bridge days after learning of the incident.