Ophir Optics Inc., which makes infrared optical products for the military, has expanded its presence at Osgood Landing in North Andover to 40,000 square feet.

The expansion is a 20 percent increase, and will result in boosting its workforce by more than 50 percent since moving to the town two years ago, according to landlord Ozzy Properties.

"This is certainly very positive news for us," said Dennis Cope, president of Ophir Optics. "We’ve been fortunate to be in some good markets, which allows us to provide solid products for our customers while growing our workforce."

Cope said the expansion is being driven largely by defense-related work orders. Ophir manufactures lenses and optical components for use in infrared optical systems, including night vision equipment used in military operations in Iraq and Afghanistan.

In December 2007, Ophir Optics signed a multi-year lease with Ozzy Properties to occupy a 32,000-square-foot space on the grounds of Osgood Landing. The company now employs 111 workers, according to a statement.

Ophir Optics’ arrival marked the first tenant to occupy space in Bell Labs’ research and development facility at the 1600 Osgood St. site in North Andover. Cope anticipates occupying the entire first floor of that facility by end of February.