Title :
A 1.3 μm directional coupler polarization splitter by ion exchange
Author :
Miliou, Amalia N. ; Srivastava, Ramakant ; Ramaswamy, Ramu V.
Author_Institution :
Dept. of Electr. Eng., Florida Univ., Gainesville, FL, USA
fDate :
2/1/1993 12:00:00 AM
Abstract :
A glass waveguide polarization splitter for operation in the 1.3 μm wavelength region is reported. The device, which has a symmetric directional coupler configuration, exploits the stress-induced birefringence in K+-Na+, ion-exchanged waveguides, giving rise to an adequate difference in the coupling lengths for the two polarizations. Starting from the measured potassium concentration (refractive index) profile of the structure and utilizing a combination of the multilayer stack theory and the effective-index method, the normal mode propagation constants and mode field profiles are calculated to determine the polarization splitting length and the extinction ratio, and the results are compared with the experimental data. It is shown that in a given coupler, the splitting occurs at several wavelengths in the 1.0-1.45 μm range. A 25 mm-long coupler, fabricated by thermal diffusion of K+ ions in BK7 glass, exhibits an extinction ratio of 18.2 dB at 1.32 μm, in excellent agreement with the simulation results
Keywords :
birefringence; directional couplers; integrated optics; ion exchange; optical constants; optical couplers; optical glass; potassium; refractive index; sodium; 1.00 to 1.45 micron; 1.32 micron; 25 mm; BK7 glass; IR; K+-Na+; coupling lengths; directional coupler polarization splitter; effective-index method; extinction ratio; glass waveguide; ion exchange; ion-exchanged waveguides; mode field profiles; multilayer stack theory; normal mode propagation constants; polarization splitting length; refractive index; stress-induced birefringence; symmetric directional coupler configuration; thermal diffusion; wavelength region; Birefringence; Directional couplers; Extinction ratio; Glass; Length measurement; Nonhomogeneous media; Polarization; Propagation constant; Refractive index; Wavelength measurement;
Journal_Title :
Lightwave Technology, Journal of
