Light source device and image display apparatus

摘要

A light source device includes a phosphor layer formed on a base, and an excitation light source exciting the phosphor. A dichroic mirror is arranged between the phosphor layer and the excitation light source and inclined with respect to a propagation direction of excitation light from the excitation light source. An incident region of the excitation light and an exiting region of fluorescence emitted from the phosphor belong to a space on the same side with respect to the surface with the phosphor layer disposed. In a dominant wavelength of the excitation light, the dichroic mirror has a spectral characteristic of transmitting 50% or more of light of a p-polarized component and reflecting 50% or more of light of a s-polarized component. Fluorescence emitted from the phosphor layer can be extracted highly efficiently and propagated by a compact and simple optical system.