Optically bistable interference filters and single bistable absorption layers were prepared by thermal and electron beam evaporation of CdSe, CdS, ZnSe, ZnS, MgF₂, Ta₂0₅ and Si0₂ on glass substrates. The bistable interference filters consist of a low absorption spacer, e.g. CdS, with multilaver mirrors on both sides and an absorption layer, e.g. CdSe, on the beam exit side. Absorption leads to heating and thermooptic tuning of the spacer resulting in optical bistability. Using low absorption spacers and an external absorber the temperature rise necessary for switching can be reduced. Therefore bistable elements allowing more than 10 mill. switching cycles have been achieved. Optical bistability is observed also in single ZnSe layers due to increasing absorption with an incident photon energy just below the band gap. The switching elements were operated between 500 and 600 nm wavelength and needed switching powers of several mW. Switching times in the microsecond range were measured.

Date Published: 8 March 1989
PDF: 5 pages
Proc. SPIE 1017, Nonlinear Optical Materials, (8 March 1989); doi: 10.1117/12.949960

Published in SPIE Proceedings Vol. 1017:
Nonlinear Optical Materials
Gerald Roosen, Editor(s)