In order to realize high coupling efficiency between single-mode fibers, micro-lenses fabricated by photoresist melting method are used. The fiber-to-fiber coupling is analyzed by the Gaussian beam relay method. The coupling efficiency of 63% is measured from the two microlens configuration and that of the one microlens configuration is 54%. The dependence of the coupling efficiency upon spatial misalignment is studied.
The multiple layer ridge waveguide is designed by spectral index method(SI). The calculated results of the SI compare quite well with the vector finite-element method. The ridge waveguide is fabricated by the chemically assisted ion beam etching technique(CAIBE). The near fields of the transverse modes are measured and compared with the calculated modes obtained by the spectral index method.
