Monolithic integration of GaAlAs superluminescent diode with the optical amplifier

Integrated superluminescent diode (SLD) was fabricated using an AlGaAs semiconductor quantum well (SQW) heterostructure wafer. A 3 ��m-wide SLD with 300 to approximately 500 ��m length is aligned with the 3 ��m-wide input aperture of the tapered amplifier. The amplifier is 1.3 to approximately 1.5 mm in length and the gain region expands linearly from 3 ��m-wide at the input end to 110 to approximately 130 ��m at the output end. The outside stripes of SLD and amplifier regions were etched slightly for restricting lateral current diffusion. Light-current (L-I) characteristics of the integrated SLD were measured under pulse conditions.