Patent ID: 6289699
Filing Date: 2001-09-18
Classification: G02B,H04J

Abstract:
A method of enhancing the performance of a fused, grating assisted mode coupler having a coupling region comprising the steps of:forming a coupler having a coupling region with a cross-sectional dimension of 20 microns or less, the coupler having substantial photosensitivity enhancing dopant throughout the cross-sectional area in the coupling region;enhancing the photosensitivity of the coupler at least in the coupling region by indiffusion of a gas into the cross-sectional area of the coupler to a level such that an actinic illumination exposure to <1kJ/cm.sup.2 impresses an index of refraction change >10.sup.-5 within the coupling region; andwriting the grating in the photosensitivity enhanced coupling region of the coupler with actinic illumination.