Abstract: A writing/erasing method for use in connection with homotropic organic optical media is disclosed and claimed. The method includes writing on a thin film with light of a first linear polarity to induce birefringence along the direction of an optical axis of the film's initial state followed by erasing the film with light of a second linear polarity. The first and second linear polarities are angularly offset with respect to one another, preferably by 90 degrees.