Extremely broadband AlGaAs/GaAs superluminescent diodes

Extremely broadband AlGaAs/GaAs superluminescent diodes are fabricated on substrate with four quantum wells of different widths. By choosing 20, 33, 56, and 125 Å, respectively, for the four quantum wells, the spectrum could be broadened to several times that of the conventional superluminescent diodes. The measured spectra of the fabricated devices with such quantum-well structure show that the full-width at half-maximum spectral width could be as large as 915 Å. © 1997 American Institute of Physics.