Mass. residents on Forbes list of billionaires
Valentin Gapontsev & family
Net worth: $1.3 billion
Overall rank: 1,107
Gapontsev, a former professor at the Soviet Academy of Sciences, launched IPG Photonics in Moscow in 1990. The now-Oxford-based company leads the world in the manufacture of fiber lasers - a specialized technology that combines high power and exceptional precision.