Coupling argon-laser light into absorbing SiO2–TiO2 waveguides, we observed at constant input power depending on the angle of incidence and the initial gap width, self-pulsing, bistability, or a special form of bistability with either a constant or a self-pulsing output. The system's dynamics is governed by two effects with different time constants, both caused by heating of the waveguide by the incoupled absorbed power: (1) thermal expansion of waveguide and prism, which reduces the coupling gap width and thus changes the incoupling efficiency, and (2) desorption of H2O molecules from the SiO2–TiO2 layer, which changes the effective guide index.
© 1987 Optical Society of America
Original Manuscript: December 30, 1986
Manuscript Accepted: April 14, 1987
Published: July 1, 1987
V. Briguet, P. Pirani, and W. Lukosz, "Self-pulsing in prism coupling into planar waveguides," Opt. Lett. 12, 525-527 (1987)