Germanium Power Devices

Germanium Power Devices Corp. was founded in 1973 and began by manufacturing high-quality germanium transistors for demanding electronic applications. From the early 1980s the company shifted its focus to optoelectronics, producing germanium and InGaAs photodiodes and detector arrays. Now trading as GPD Optoelectronics, the family-owned business supplies germanium pn detectors, standard and extended-wavelength InGaAs detectors, customisable two-colour detectors and quadrant photodiodes, and has relocated to an expanded facility in Salem, New Hampshire. Its devices are used in aerospace, industrial and scientific instrumentation.

Sources: source 1