The application of optical thin‐film interference structures, consisting of epitaxial III‐V alloy layers, to the fabrication of optoelectronic devices operating in the 1–10‐&mgr;m wavelength range which are suitable for two‐dimensional array integration and relevant to optical communications and computing is discussed. This paper deals with surface geometry narrow band filters and current injection modulators. Closely related surface lasers will be described in a subsequent publication. An environmentally stable filter consisting of GaAs and AlAs epitaxial layers with a passband width of 1.2 nm at a wavelength of 1.6 &mgr;m is demonstrated. Such filters are found to be tunable by tilting. A proposed design for a surface current injection modulator operating at a wavelength of 1.3 &mgr;m is given with a modulation ratio of 10:1 anticipated for an operating current of 5 mA. The significant advantages of compound semiconductor expitaxial layers over polycrystalline coatings for general thin‐film optics applications are outlined briefly.