France Telecom Etablissement Autonome De Droit Public

Etat Francais Represente Par Le Ministre

Jean Landreau

Hisao Nakajima

The present invention pertains to a method and apparatus for the deposition and measurement of anti-reflective coatings on non-resonating semiconductor laser amplifiers. Two faces (15-1, 15-2) of the amplifier (15) alternately receive the sputtered material in small quantities. The semiconducting structure is supplied with constant current (16) and the voltage (V) is measured at the terminals of the structure. When the coatings are deposited on both faces, the voltage increases and passes through a maximum corresponding to the reflectivity minimum at which point deposition of the coating is stopped. The two faces are treated in the same way with coatings of the same thickness.

Process and apparatus for the deposition of anti-reflection coatings and

Method to control the thickness of an antireflection coating. According to the invention, the semi-conductive structure (14) is fed with a constant current (16) and the voltage (24) is measured at its terminals. This voltage passes through a maximum when the reflectivity of the antireflection coating passes through a minimum. Application for the embodiment of semi-conductive lasers.

Growing community of inventors

Antony, France

Jean Landreau