Wavelength-tunable light source

摘要

A wavelength-tunable light source (1) includes an emitting section (3) that emits light having a plurality of single wavelengths on a substrate (2). Surface-emitting lasers (4a-d) are arranged in close proximity to each other on the substrate in the emitting section. The number of surface-emitting lasers corresponds to the number of wavelengths to be emitted. The light with the wavelengths emitted from the respective surface-emitting lasers is incident on a medium at substantially the same position.