1982/04/01 by M. Austin, Michael W. Austin · 44 citations
Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #Advanced Fiber Optic Sensors #Bend radius #Bending #Composite material #Coupling loss #Curvature #Dielectric #Dielectric loss #Geometry #Insertion loss #Materials science #Multi-mode optical fiber #Optical fiber #Optics #Optoelectronics #Photonic and Optical Devices #Physics #RADIUS #Radiation #Radius of curvature #Return loss #Scattering #Telecommunications #Waveguide
paper · doi:10.1109/jqe.1982.1071580
published in IEEE Journal of Quantum Electronics 18(4), 795-800 (IEEE Photonics Society)
openalex publication_date 1982/04/01 · openalex created_date 2025/10/10 · openalex updated_date 2025/11/06
Curved dielectric optical waveguides suffer from radiation loss due to bending. To minimize the bending loss and reduce the radius of curvature, it is necessary to fabricate guides which provide strong optical confinement. This paper gives a brief review of curved waveguide analysis and presents some experimentally measured loss values for GaAs/GaAlAs curved rib waveguides. The rib waveguides, fabricated using ion beam milling, have a large rib height and are tightly guided structures. When corrected for reflection losses and input coupling efficiency, a minimum loss of approximately 3 dB has been achieved for a multimode 90° curved guide with a radius of curvature of 300 μm, and 8.5 dB for a single-mode curved guide with a radius of curvature of 400 μm. It is believed that most of this residual loss is not radiation loss due to bending, but rather scattering loss due to rib wall imperfections.