| abstract |
An organic nonlinear optical material comprising a 4-nitrophenylaminoacetaldehyde acetal of the following formula (I): ##STR1## wherein R 1 , R 2 and R 3 each represent a hydrogen atom, or a linear or branched alkyl group having 1 to 6 carbon atoms, and R 4 represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, a nitro group or a halogen atom. |