OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To enhance the sensitivity of a long wavelength side by providing a recording layer which contains specific azulenium salt compound. CONSTITUTION:A recording layer which contains azulenium salt compound represented by a formula I is provided. In the formula I, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10 and R11 are hydrogen atom, halogen atom or univalent organic residue, or substituted or unsubstituted condensed ring may be formed of one of the combinations of R1 and R2, R2 and R3, R3 and R4, R4 and R5, R5 and R6, and R6 and R7, R12 and R13 are substituted or unsubstituted alkyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted styryl group or substituted or unsubstituted heterocyclic ring. N is 1 or 2. Z indicates anionic residue. Thus, a recording can be performed with high sensitivity by absorbing at long wavelength side and using long wavelength oscillation laser to obtain a high C/N ratio.