| Summary: | 碩士 === 大葉工學院 === 電機工程研究所 === 84 === The successful development of optical networks toward
fiberto home system will require development of low cost
passive optical branching components. At present,
commercially-available components are expensive, bulky, and
have inconsistent performance. Silica-on-silicon integrated
optics technology is well suited to fabrication of such device.
In this thesis, single-mode Ge or Ti doped silica glass
waveguide have been formed on Si wafer by flame hydrolysis
deposition. The fabrication process is reproducible and
produces waveguide with a loss < 0.1dB/cm at a wavelength
1.3μm. The maximum ⊿n achieved are 0.8% and 0.5% for Ge doped
and Ti doped waveguide respectively.
Besides, a new method of automatically coupling between fiber
and an optical waveguide is disclosed. A key feature of
this technology is that V-grooves for holding the input and
output fibers can be precisely defined in silicon substrate
as part of the waveguide fabrication, allowing passive fiber
to waveguide alignment, leading to low cost device assembly and
rugged fiber to waveguide coupling. The etched depth for
opening V-groove window was minimized to be about 7μm in
this method. Alternatively, such a process also reveals high
reproducibility. By this invention, the alignment time of
fiber-to-waveguide is saved to 1/30 of conventional active
alignment. In addition, another invention relative to
methods for fabricating glass diaphragm on a silicon
microstructure was proposed. More specially, the present
invention relates to methods for fabricating glass diaphragms
and/or diaphragm-sealed chambers for use in
microelectromechanical systems (MEMS), such as pressure
transducers, microvalves, accelerometers, shear-stress
sensors, etc.
We fabricated several types of single mode S-band based 1*N
splitters using above technology. By cascading simple 1*2 S-
band splitters, 1*4 and 1*8 circuits were fabricated. For an
active alignment packaged 1*8 splitter, average insertion loss
of ＜11.5 dB was obtained with a uniformity of ＜1dB. For a
passive alignment packaged single channel waveguide, average
insertion loss of 2.8 dB of a 2cm long waveguide with an
uniformity of 1.2 dB were obtained. Although this
performance is not good, a further improvement is possible
by optimizing the fabrication parameter and process. A coupling
loss of below 1dB is expectant.
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