Uncooled 25 Gbit/s direct modulation of semi-insulating buried-heterostructure 1.3 µm AlGaInAs quantum-well DFB lasers

Uncooled 25 Gbit/s direct modulation of 1.3 µm DFB lasers is demonstrated. The 150 µm-long semi-insulating buried-heterostructure AlGaInAs quantum-well DFB lasers show clear eye-openings with dynamic extinction ratio of 5 dB up to 70°C. 13 km singlemode-fibre transmission experiments using the devices show low power penalty within 1.3 dB between 25 and 70°C. These characteristics are the first achievement by 1.3 µm directly modulated lasers.