The present invention provides a heat-sensitive recording material that comprises a support, a heat-sensitive recording layer comprising a leuco dye and a developer, and a protective layer principally comprising a pigment and a binder. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The movable girder has the same under-clad layer, core layer and over-clad layer as the wave-guide-type diffraction grating.