Patent ID: 6556731
Filing Date: 2003-04-29
Classification: B41J,G02B,G02F

Abstract:
A waveguide mode filter comprising:a gallium arsenide substrate comprising layers of materials arranged to confine an electrical field in a relatively small thickness and wherein the said layers include: an N-doped gallium arsenide substrate; an N-doped aluminum gallium arsenide layer formed over said substrate; an N-doped gallium arsenide layer formed over the N-doped aluminum gallium arsenide layer; a P-doped gallium arsenide layer formed over the N-doped gallium arsenide layer; a P-doped aluminum gallium arsenide layer formed over the P-doped gallium arsenide layer; and a P-doped gallium arsenide layer formed over the P-doped aluminum gallium arsenide layer; and a necked waveguide having: a relatively broad input end which receives light and allows propagation of multi-mode light waves therethrough; a narrowed neck portion at which higher modes radiate outside the waveguide and only the modes which can propagate therethrough pass therethrough providing mode filtering; and a relatively broad output end.