A 1.55-mu-m GaInAsP/InP optical amplifier integrated with access waveguides provides 0 dB fibre to fibre gain at only 47 mA bias current and a 5 dB saturation gain already high enough to design 0 dB integrated complex circuits. Polarisation gain dependence and gain ripple are less than 0.5 dB and 0.7 dB, respectively.