| 摘要 |
PROBLEM TO BE SOLVED: To reduce the cost of an optical semiconductor device using a substrate with power feeding lines, by preventing the length of its optical semiconductor element from being lengthened even when disposing a plurality of signal wirings on its sub-mount. SOLUTION: In the substrate, power feeding lines 3-9 requiring a large area are so disposed on the different side surface of a sub-mount 1 from its monitoring surface for an optical semiconductor element 2 as to make reducible a width W of the sub-mount 1 even when disposing thereon the plurality of power feeding lines 3-9. As a result, the length of the optical semiconductor element 2 mounted on the top surface of the sub-mount 1 is so made nearly as short as the width W of the sub-mount 1 as to make reducible the size of the optical semiconductor element 2. |
