| 摘要 |
PURPOSE:To provide a hermetic structure which is small and highly reliable of a waveguide type optical device formed with an optical waveguide in a first substrate. CONSTITUTION:A second substrate 6 consisting of the same material as the material of the first substrate 1 or having a coefft. of thermal expansion nearly equal to the coefft. of thermal expansion of the first substrate is provided with a groove 7 axisymmetrical with the optical waveguide 2. This second substrate 6 is put on the first substrate and is joined thereto. The circumference of the one substrate and the surface of the other substrate are fixed by any of solder, low melting glass or resin. An optical fiber 10 to be joined to the optical waveguide 2 is arranged in the groovs 8 formed on the first substrate 1 and is held by the groove 9 formed in the second substrate 6. The spacings of both grooves 8, 9 and the optical fiber 10 are packed by the solder or low melting glass. As a result, there is no need for housing the entire part of the substrate formed with the optical waveguide 2 into a hermetic casing and, therefore, the size and cost are reduced. In addition, the use of a resin for fixing is not required as there is no fixing of the substrate. This structure is stable to a change of ambient temp. as well. |
