A semiconductor laser device includes a laser diode provided on a semiconductor substrate, the laser diode including a first optical waveguide having a gain waveguide, a plurality of photodiodes, a first wavelength-selective filter having periodic transmission peaks, and a second wavelength-selective filter having periodic transmission peaks, the period of the transmission peaks of the second wavelength-selective filter being different from the period of the transmission peaks of the first wavelength-selective filter. Furthermore, two photodiodes among the plurality of photodiodes are optically coupled to the first optical waveguide through the first and second wavelength-selective filters, respectively.