Mary Masterman, a senior at Westmoore High School in Oklahoma City, was named the winner Tuesday of the annual Intel Science Talent Search.
More than 1,700 high school seniors across the nation entered the contest, which is in its 66th year.
Spectrographs, which measure wave lengths, are used in research such as astronomy and medicine and in industry. For example, they can be used as a sensing device to look for explosives or drugs or to help determine how old an art work is through its pigments.
They can cost as much as $100,000, but Masterman's invention - made of lenses, a laser, aluminum tubing and a camera - costs less than $1,000, Intel said.
Masterman received the honor from Intel Corp. Chairman Craig Barrett during a banquet Tuesday night in Washington.
''It was a complete surprise,'' Masterman said. ''I wasn't expecting it.''
The 40 finalists spent the last week in Washington, where they exhibited their projects at the National Institute of Science and met government officials including Vice President Dick Cheney.
Masterman said she has been interested in science ''ever since I was little. I can't remember ever not being interested.'' She credits her parents with encouraging her.
She said she has not decided where she will attend college but would eventually like to become a physicist or chemist.
Among the former winners of the competition's top award are six Nobel Laureates, three National Medal of Science winners, 10 MacArthur Foundation Fellows and two Fields Medalists.
''You're not only dealing with the top young person in the science field in the country in Mary, but you're dealing with 40 finalists who are doing breaking-edge research in total,'' said Brenda Musilli, Intel's director of education. ''It's really something that's hard to imagine, how a young person like Mary could even achieve this level of capability at such a young age.''