| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive method suitable for mass production, by which a diffraction grating for joining and dissociating light to and from a dielectric coating film having a high refractive index on a base board system. SOLUTION: In the method for manufacturing a diffraction grating structure to join and dissociate light to and from a dielectric coating film 2 having a high feractive index on a base board 1, ultraviolet laser beams 12a and 12b whose intensity is simultaneously, spatially and periodically modulated are irradiated to the dielectric coating film 2 having a high refractive index and/or base board 1, and an intensity modulating period is selected in response to a desired grating period. Perferably, intensity is modulated by at least two ultraviolet laser beams 12a and 12b interfering with each other or preferably, by a mask structure, and the ultraviolet laser beams are formed of one or more excimer lasers, and the ultraviolet laser beams are preferably oscillated one or more times in pulse time not more than 1μs in a prescribed time, and a refractive index of the coating film 2 having a high refractive index and/or at least a surface area of the base board 1 is spatially modulated by the laser beams 12a and 12b. |
