All-active tapered 1.55-mu-m InGaAsP-BH-DFB laser with continuously chirped grating

We demonstrate the first realization of all-active tapered index coupled 1.55 µm InGaAsP-BH-DFB-lasers involving chirped gratings. The variation of the effective refractive index along the tapered active stripe is compensated using an optimized continuously chirped grating. The grating has been formed by direct write electron-beam lithography. Lasers with a AR/cleaved cavity show stable single mode operation and high optical output power up to 60 mW. The yield of lasers with a SMSR > 40 dB is more than 70 %. The -3dB farfield angles (FWHM) amount to 14° and 20° in lateral and vertical direction, respectively.