| Summary: | 碩士 === 國立交通大學 === 電子物理學系 === 85 === In this thesis, we studied the nonlinear
saturable absorption and reflectivity of the
saturable Bragg reflectors. The device structure can be regarded
as a high reflectivity Bragg mirror incorporated
with semiconductor InGaAlAs/AlGaAs muilti-
quantum wells. These wells are used as saturable absorbers whose
optical property dominates the dynamics of
passive mode-locking. The overall device structure is
controlled by molecular beam epitaxy (MBE) . It is successfully
used for passive mode locking the Ti:sapphire
laser to obtain 100fs ultra-short pulses. Besides,we
observe the alteration of reflectivity by changing the thickness
of epitaxial lay ers and compare it with
simulation results. the experimental data shows that when
the absorption peak of the multiquantum wells is located within
the high-broad re -flection band, the
charateristics of the output pulses, such as pulse width, tun
-ing range, and stability...etc.,can be highly improved.
Finally, the optical pro -perties of strained
quantum well and the dynamics of mode-locking are also diss-
cussed.
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