DEVICE AND METHODS UTILIZING OPTICAL WAVEGUIDE EMBEDDED BLAZED REFRACTIVE GRATINGS

摘要

In a broad aspect, the invention is an optical device that comprises an optical waveguide having a blazed Bragg grating such that at least a portion of the light coupled from a guided mode into radiation light beam or beams. The light outcoupled by the blazed fiber grating is focused onto a intermediate image on an intermediate image plane at a first predetermined position peculiarly depending on the wavelength of the light and the effective refractive index of the guided mode from which the light is coupled. The invention may comprise a spatial light modulator placed at the intermediate image plane which serves to control phase and amplitude components of the light beam or beams. More significantly, the invention further comprises a final focusing component which may be a lens used to focus the light beam exiting the spatial light modulator onto a final image on small area such that light intensity is increased and thereby the detection sensitivity is improved. The invention furthermore comprises a light receiver which could be a photodetector or a photodetector array used to detect the final image.