He worked on highly sensitive submarine propulsion systems as an engineer for Anaheim-based naval defense contractor Power Paragon.
Mak was arrested in late 2005 in Los Angeles after FBI agents stopped his brother and sister-in-law as they boarded a flight to Hong Kong and Guangzhou, China.
Investigators said they found three encrypted CDs in their luggage that contained documents on a submarine propulsion system, a solid-state power switch for ships and a PowerPoint presentation on the future of power electronics.
Mak wanted a new trial, but a judge denied the request earlier this year.
