In this study, a multi-wavelength laser monolithically integrated on InP is presented. A linear laser cavity is built between two integrated Sagnac loop reflectors (SLRs), with an arrayed waveguide grating (AWG) as frequency-selective device, and semiconductor optical amplifiers as gain sections. The power is out coupled from the cavity using a side diffraction order of the AWG. Simultaneous laser operation is provided for four wavelengths/cavities in the device. The termination of the laser cavities with integrated SLRs avoids using high-reflection coating. Only anti-reflection coating is used in the output facet of the chip.