Title :
Polarization independent integrated mode transformer for uncladded InGaAsP/InP rib waveguides without epitaxial regrowth
Author :
Albrecht, P. ; Heidrich, H. ; Loffler, R. ; Morl, L. ; Reier, F. ; Weinert, C.M.
Author_Institution :
Heinrich-Hertz-Inst. fur Nachrichtentech. Berlin GmbH, Germany
Abstract :
A polarization insensitive fibre port for integration in complex PICs has been demonstrated. The spot-size transformation is performed by a thickness taper integrated with an uncladded InGaAsP/InP rib waveguide in cooperation with guiding layers in the waveguide buffer. No epitaxial overgrowth is necessary to achieve polarization independent coupling. The thickness taper is structured by using shadow mask ion beam etching. The first fabricated integrated spot size transformers show a polarization independent coupling loss of 2.3/spl plusmn/0.2 dB (butt coupled cleaved fibre). The radiation loss along the waveguide taper amounts to 0.6 dB. The -1 dB-alignment tolerances are larger than /spl plusmn/2.4 /spl mu/m. A theoretical coupling loss of 1 dB is predicted for an optimized waveguide shape. The high yield fabrication process is suited for integration of the spot size transformer in complex PICs.
Keywords :
III-V semiconductors; gallium arsenide; indium compounds; integrated optics; optical couplers; optical fabrication; optical losses; rib waveguides; sputter etching; 0.6 dB; 2.1 to 2.5 dB; InGaAsP-InP; alignment tolerances; core thickness tapering; coupling loss; flat-end fibres; guiding layers; high yield fabrication process; integration; optimized waveguide shape; photonic IC; polarization independent coupling; polarization independent integrated mode transformer; polarization insensitive fibre port; radiation loss; shadow mask ion beam etching; spot-size transformation; thickness taper; uncladded InGaAsP/InP rib waveguides; waveguide buffer;
Conference_Titel :
Optical Communication, 1996. ECOC '96. 22nd European Conference on
Conference_Location :
Oslo, Norway
Print_ISBN :
82-423-0418-1