EFFECTS OF AIR GAPS ON BUTT-JOINTS BETWEEN ISOTROPIC AND ANISOTROPIC PLANAR WAVE-GUIDES

Power transmission properties are investigated for a butt-joint which contains an air gap between an isotropic planar waveguide and an aniso tropic one whose optical axis is lying in the plane defined by the pro pagation axis and the normal of the waveguide surface. New transmissio n coefficients are introduced for estimating the optical-power which i s launched out into the gap from the incoming waveguide. Wave propagat ion through the gap is analyzed on the basis of the BPM concept. And t he power transmitted across the interface between the gap and the outg oing waveguide is evaluated by means of the overlap integral of the fi eld profiles. The effects of the air gap and the refractive index of f illing liquid as well as axial displacement and angular misalignment a re discussed on the basis of numerical results.