Patent ID: 6122422
Filing Date: 2000-09-19
Classification: G02B

Abstract:
An article comprisinga) an optical waveguide adapted for guiding light of a predetermined wavelength in a first direction as well as for guiding light of the predetermined wavelength in a second direction opposite the first direction; andb) a tap for coupling from the optical waveguide at least some of the light that is propagating in the optical waveguide in the first direction, and for coupling from the optical waveguide at least some of the light that is propagating in the optical waveguide in the second direction;c) the optical waveguide is a single mode optical waveguide adapted for guiding fundamental mode light in the first and the second direction;d) the tap is a bi-directional tap that comprises a blazed refractive index grating in the optical waveguide;e) the blazed refractive index grating is selected to direct at least some of the light that is propagating in the first direction in the waveguide from the first fundamental mode into at least one first non-guided mode, and to direct at least some of the light that is propagating in the second direction in the waveguide from a second fundamental mode into at least one second non-guided mode;f) the article comprises at least one coupling element that is in optical co-operation with the optical waveguide such that the first and second non-guided modes respectively are first and second radiation modes; andg) the article comprises at least one focusing element selected to bring the light in the first radiation mode substantially to a focus on a predetermined region of a first utilization element, and to bring the light in the second radiation mode substantially to a focus on a predetermined region of a second utilization element.