The companies are Computer Optics, irZoom and Hudson Machining.
irZoom, now a Clear Align company, designs and manufactures infrared zoom and fixed focal length lenses for applications that demand high optical performance over wide zoom ranges and specializes in rugged systems for commercial and military environments.
Computer Optics makes custom optical components.
Clear Align said the addition of Hudson Machining will add in-house, quick-turn mechanical prototype capabilities to its portfolio.
Terms of the acquisitions were not detailed but Clear Align said the transactions would be neutral to 2012 earnings.
The three acquired companies are all located in Hudson, N.H.
"These acquisitions are part of an overall strategy to expand our international presence and enable quick turn, in-house prototypes to customers," said Angelique X. Irvin, chief executive officer of Clear Align. "irZoom and Computer Optics strengthen our portfolio of offerings and discriminators in the tactical intelligence, surveillance and reconnaissance market and expand our market to serve commercial and medical customers.
"The complementary irZoom brand has a respected international presence that we plan to support. We will further invest in expanded optical component manufacturing allowing us to provide more diverse quick-turn optics to better serve an increasingly demanding optics marketplace.
Obama 'selfie' photographer speaks out: 'Photos can lie'
Video of Victoria’s Secret models trying to 'twerk' hits Instagram