Abstract. We report a hybrid integrated external cavity laser by butt coupling a quantum dot reflective semiconductor optical amplifier and a silicon-on-insulator chip. The device lasers at 1302 nm in the O-band, a wavelength regime critical to data communication systems. We measured 18 mW on-chip output power and over 50-dB side-mode suppression ratio. We also demonstrated open eye diagrams at 10 and 40 Gb∕s. © The Authors.Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.