| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluorescent light source device in which, when excitation light is irradiated on a wavelength conversion member, the back scattering of the excitation light is restricted, resulting in high luminous efficiency being obtained.SOLUTION: Provided is a fluorescent light source device equipped with a wavelength conversion member having a phosphor which is excited by excitation light, said device being characterized in that a periodic structure is formed on an excitation light receiving face in the wavelength conversion member, and that the cycle of the periodic structure is less than or equal to the wavelength of the excitation light. The cycle of the periodic structure should preferably be somewhere in the range in which there occurs a diffraction of fluorescent light radiated from the phosphor. |
