In fabricating a monochromic and highly coherent light source, no single crystalline bulk semiconductor is used, but two different kinds of transparent substances are alternately stacked over each other to constitute a periodic structure in 1/2 of the intended wavelength. At least one of the two kinds of transparent substances is controllable in electric conductivity, and the structure is such that inside a medium consisting of this kind of transparent substance light-emitting semiconductor particulates are embedded. Accordingly, a light-emitting device has this structure, which makes possible control of the center wavelength of light emission, the width of wavelength distribution and coherence by adjusting the geometrical parameters of the device without having to alter the kind of material use.