Very low-loss fiber-to-waveguide coupling using diffraction optical element mode converter

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)22_Publication in policy or professional journal

View graph of relations


Related Research Unit(s)


Original languageEnglish
Pages (from-to)320-328
Journal / PublicationProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - 2002


TitleOptical Fiber and Planar Waveguide Technology II
Period16 - 18 October 2002


Very low-loss coupling between standard single-mode fibers (SMF) and high refractive-index waveguides is achieved using diffraction optical element (DOE) as mode converter. The DOE is a beam-shaping element designed based on diffraction optics theory. DOE shapes the mode field of SMF to that of the waveguide, or vice versa. The mode mismatch between them is eliminated. DOE is a pure phase element, which phase distribution optimized by G-S algorithm. The most attractive point of this mode converter is that the DOE can be designed to achieve any mode field distribution of any waveguide structure. This advantage makes DOE a strong and flexible mode converter. Though being a phase element, DOE has certain wavelength tolerance covering a sufficiently wide band, which makes it applicable in multi-wavelength integrated planar lightwave circuits (PLCs). DOE can be approximated by binary optical element (BOE), so that it can be fabricated using existing PLC fabrication steps.

Research Area(s)

  • Diffraction optical element (DOE), Fiber-to-waveguide coupling, Mode converter