A method of manufacturing a controlled release fertilizer wherein the fertilizer is deposited onto a first polymer film and then covered by a second polymer film to encapsulate the fertilizer between the first polymer film and the second polymer film. A gate insulating film has a layered structure including a first insulating layer containing an oxide and a second insulating layer disposed on the side closer to the gate electrode closer than the first insulating film and having a higher dielectric constant than the first insulating film, the layered structure being in contact with the oxide semiconductor layer. Other design wavelengths, bend angles and displacements are possible through appropriate adjustment of grating frequency, prism geometry, andor material.