Patent ID: 7215886

Claim:
A transmitting optical communication module comprising: a receptacle for connecting an optical fiber from an external side of said optical communication module; a transmitter module comprising: a can-cap comprising a lens; a light emitting element; a ceramic substrate; at least one signal transmission line of said light emitting element disposed on said ceramic substrate and having a connecting segment that is narrower than a remaining segment thereof; a pair of ground lines disposed on said ceramic substrate and extending along both sides of said signal transmission line, each ground line having a connecting segment that is narrower than a remaining segment thereof; and a can-stem provided with a through-hole, wherein said ceramic substrate is fixed through said through-hole of said can-stem, wherein said light emitting element is disposed in a space within said can-cap which is sealed off by said can-stern, said light emitting element being optically coupled to said optical fiber via said lens, wherein spacing between said connecting segments of said signal transmission line and said ground lines is greater than spacing between said remaining segments thereof; a flexible wiring board having disposed thereon conductors, each conductor having a first connecting segment and a second connecting segment, both of which are narrower than a remaining segment thereof, wherein, spacing between said first connecting segments and spacing between said second connecting segments each is greater than spacing between said remaining segments; and a printed circuit board having disposed thereon conductors, each conductor having a connecting segment that is narrower than a remaining segment thereof, wherein spacing between said connecting segments is greater than spacing between said remaining segments, said connecting segments of said signal transmission line and of said ground lines being connected to respective ones of said first connecting segments of said flexible wiring board conductors, said second connecting segments of said conductors of said flexible wiring board being connected to respective ones of said connecting segments of said printed circuit board conductors, wherein a high frequency characteristic impedance of said signal transmission line is matched to about 50Ω.