Improved wavelength trimming of distributed-feedback lasers using very narrow multiple quantum wells

We succeeded in wavelength trimming DFB lasers over a 0.44-nm spectral range toward long wavelengths. This improved spectral range is made possible by using narrow 2.7 nm multiple quantum well active region. We fabricated DFB lasers that have active layers consisting of fifteen compressively-strained InGaAs quantum wells. The wells are 2.7-nm wide and are separated by 1O-nm InGaAsP barriers. The SCH structure was grown on an n-type InP substrate by low pressure metal organic vapor phase epitaxy.