A portable rock crusher is adapted for attachment to a boom of an earthmoving vehicle. A recording clock generator 9 is included in the laser driving waveform generator 2 to generate a clock with a frequency higher than that of a synchronizing clock 202. The polar groups are connected to the hydrophobic groups by means of a linker. With the configuration, it is possible to embed additional information such as key information used for decoding contents, key production information, contents reproduction control information, and copying control information with a format hard to analyze and also to accurately read out for data reproduction.