Laser radiation having a plurality of discrete wavelengths is generated by apparatus including a resonant cavity and a non-linear element within the cavity. Medical data is separated into bulk content and metadata. The band pass filter band pass filters the VLIF information signal. Dimer diamine andor dimer acid may be present in the reaction mixture. In another embodiment, the reaction chamber itself is rotated while the wafer is kept stationary. The discomfort index is decreased by reducing the high frequency component, charging noise, metallic impulsive sound and the like of the image formation apparatus, to thereby contribute to the improvement of the use environment.