Surface modification of poly[2-methoxy,5-(2-ethyl-hexyloxy)-1,4-phenylenevinylene] in the optical near field

We have studied the optical properties and the surface morphology of the conjugated polymer poly[2-methoxy,5-(2ʹ-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV), under laser irradiation at 488 nm emanating from the Al coated fiber probe of a near field scanning optical microscope. Laser irradiation of the polymer in the near field induces a degradation of the material demonstrated by a dynamic change in its optical transmission. The surface of the material is modified primarily by heat conduction from the fiber probe, which under our experimental conditions is the dominant heating mechanism in the near field.