Abstract: An optical crosspoint switch structure is disclosed. The switch permits light signal to be diverted from any arbitrary number of input ports to any or several of an arbitrary number of output ports. The switch consists of two groups or intercepting optical waveguides formed on a planar substrate, which are the input and output waveguides respectvely. At each intersection another waveguide is formed above the input and output waveguides. Optical coupling between this upper waveguide and the input/output waveguides is controlled by an electrical or optical signal. The upper waveguide has a corner mirror at the intersection. When the control signal allows, light couples from the input waveguide to the upper waveguide. After being reflected by the corner mirror, the light couples from the upper waveguide into the output waveguide. The upper waveguide incorporates the active switching element. Allowing high modulation depth and low crosstalk level.