Joseph Ritter von Fraunhofer was a Bavarian physicist and optical lens manufacturer. He made optical glass and achromatic telescope objective lenses, invented the spectroscope, and developed diffraction grating. In 1814, he discovered and studied the dark absorption lines in the spectrum of the sun now known as Fraunhofer lines.
The German research organization Fraunhofer Society is named after him and is Europe's biggest Society for the Advancement of Applied Research.