Low distortion up to 2 GHz in 1.55 μm multiquantum well distributed-feedback laser

Abstract

The distortion characteristics of multiquantum well (MQW) distributed-feedback (DFB) lasers emitting at l.55 μm wavelength are investigated over a wide frequency range. The relaxation oscillation frequency fr of the MQW DFB laser is 13 GHz at Ib = 77 mA, which is about 1.5 times larger than that of a DFB laser with a bulk active layer. Owing to the high relaxation oscillation frequency characteristics and the good linearity of the light-output against injection-current curve of the MQW DFB laser, extremely low distortion characteristics (IM2 < − 65 dBc) are achieved up to a high modulation frequency of 2 GHz.