An integrated optical filter device that is tunable with a narrow linewidth and fast operation, and that can be configured to perform a number of filtering functions, including pass-through and multi-channel drop functions, redirecting optical radiation of different wavelengths into different optical channels. The filter device is easy to fabricate inexpensively and reliably using existing technology and is compact and more densely packed than devices produced by the prior art, even for low refractive index materials, in that it uses substantially straight rather than curved strip optical waveguides. Wavelength tuning can be accomplished by means of a number of alternative control arrangements and configurations.