A light source apparatus for radiating an induced emission light from a semiconductor laser device (200) to a free space via a multiple scattering optical system. The multiple scattering optical system comprises a first region (204) close to the semiconductor laser device (200) and a second region (205), which is in contact with the first region (204) and leads to the free space. A scattered substance is contained at a high concentration in the first region (204), the second region (205) has a lens section (205a) as a magnifier for at least the principal part of a secondary face light source formed over the boundary face between the first and second regions (204, 205). Thus, a simple constitution provides a low-power consumption light source apparatus small is size, low in cost, and suitable for an optical communication system having a high-speed, wide-range communication area, and an optical communication module comprising this apparatus. This apparatus enables a high efficiency of extracting light safe to human eyes even with a high-output semiconductor light-emitting device.