Sequence influence of nonidentical InGaAsP quantum wells on broadband characteristics of semiconductor optical amplifiers--superluminescent diodes.

Extremely broadband emission is obtained from semiconductor optical amplifiers-superluminescent diodes with nonidentical quantum wells made of InGaAsP/InP materials. The well sequence is experimentally shown to have a significant influence on the emission spectra. With the three In(0.67) Ga(0.33) As(0.72) P(0.28) quantum wells near the n -cladding layer and the two In(0.53) Ga(0.47) As quantum wells near the p -cladding layer, all bounded by In(0.86) Ga(0.14) As(0.3)P(0.7) barriers, the emission spectrum could cover from less than 1.3 to nearly 1.55 microm, and the FWHM could be near 300 nm.