Abstract: An optical module equipped with at least one optical component, a package for housing the one optical component, and a joining portion. The joining portion is formed within the package by Sn—Ag solder containing 2.0 to 5.0 wt % Ag and 2.0 to 20.0 wt % Au, or Sn—Zn solder containing 6.0 to 10.0 wt % Zn and 2.0 to 20.0 wt % Au.

Abstract: The present invention discloses a diameter-reducing member joint device, where connecting a first member to be connected as the boss of a flange joint or composed of relatively large-diameter pipes to a second member to be connected and having an outer diameter smaller than that of the first member, characterized by interposing a diameter-reducing pipe joint, which has at one end a large-diameter connection portion connected to the first member and also at the other end a small-diameter connection portion connected to the second member, between the first and second members to be connected, and by using a ring-like or cylindrical heat-shrinkable member made of a heat-shrinkable type of shape memory alloy.