| 摘要 |
PROBLEM TO BE SOLVED: To provide a 3-wavelength laser which can retrieve the wavelengths of three types at two optical axes and which can be used as a light source for an optical pickup with a small size and a low cost. SOLUTION: The semiconductor laser apparatus comprises a first semiconductor laser 123 for oscillating a light having a first wavelength with a variable oscillation wavelength in a predetermined range, a second semiconductor laser 122 for oscillating the second wavelength different from the first wavelength, and a second harmonic element 133 which can generate a second harmonic wave of the light having the first wavelength. |
