Omniguide Inc. raised $1.8 million in equity financing, almost a year to the day from a previous $25 million private equity round.

The Cambridge-based flexible laser scalpel maker reported selling an undisclosed amount of equity to an unnamed investor or investors for $1.84 million.

Omniguide makes a small, flexible laser scalpel, the BeamPath CO2 laser energy system, which can be used in during procedures in difficult-to-reach portions of the human body, such as surgery to remove tumors from the throat.

The company is the brainchild of co-founder Yoel Fink, who developed the technology in 1998 while a graduate student at M.I.T.

Fink and some classmates developed a “perfect mirror,” which doesn’t conduct electricity and reflects light more efficiently, for the Defense Advanced Research Projects Agency (DARPA), the U.S. Defense Department’s research arm, according to Scientific American magazine.

Omniguide invested more than $70 million in developing the technology since 2000, according to the magazine; inside every BeamPath device are roughly 20 layers of these microscopic mirrors. The technology was licensed from M.I.T. in 2003 and the device was commercialized in late 2006.

Last May, the company closed an E round of financing with the Psilos Group, 3i, Argonaut Ventures and Stata Ventures, an investment fund led by Analog Devices co-founder Ray Stata. The funds, according to the company, were to be used to expand BeamPath’s clinical indications into otology, spinal surgery, neurosurgery, gastroenterology and gynecology.