SEMICONDUCTOR LASER DEVICE AND OPTICAL DEVICE

PROBLEM TO BE SOLVED: To provide a semiconductor laser device which can be made compact even where a plurality of semiconductor laser elements are mounted thereon.SOLUTION: A three-wavelength semiconductor laser device 100 (semiconductor laser device) comprises a heat radiating base 40, pad electrodes 41, 42 and 43 arranged on an upper surface 40a of the heat radiating base 40 in a B2 direction, a blue-violet semiconductor laser element 10, a red semiconductor laser element 20 and an infrared semiconductor laser element 30 bonded to the upper surfaces of the pad electrodes 41, 42 and 43, respectively, and emitting laser light in an A1 direction intersecting the B2 direction, and a PD 60 having a light receiving surface 60a arranged on the rear side (A2 side) with respect to the blue-violet semiconductor laser element 10, the red semiconductor laser element 20 and the infrared semiconductor laser element 30. The pad electrode 42 includes a lead-out wiring part 42b arranged on the light receiving surface 60a of the PD 60.