| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element, a semiconductor light-emitting element module, and an optical pulse tester, capable of emitting light having a plurality of wavelengths from the same end surface, of operating light having a long wavelength at a high output in a fundamental lateral mode, of suppressing a radiation mode at a butt joint interface, and of obtaining a high fiber output.SOLUTION: A plurality of active layers 13 and 14 are arranged from a first light emission end surface 10a toward a second light emission end surface 10b in an order that a gain band is reduced, and include stripe parts 13a and 14a having a constant stripe width. A stripe width of the stripe parts 13a and 14a is equal to or less than a cut-off width by which light generated at the active layer 13 having a long wavelength side gain band becomes a fundamental lateral mode waveguide. The active layer 13 further includes a taper part 13b connecting between the stripe parts 13a and 14a, and whose width is continuously reduced toward the stripe part 14a of the active layer 14 having a short wavelength side gain band. |
