for Promoting Academic Excellence of Universities
of Optical-MEMS for Light Modulation
(MEMS) is a rapidly developing technology with promising
applications to optical switching fabrics, optical sensors,
displays, micro-actuators etc. The purpose of the subproject
is to utilize MEMS technology to fabricate miniature
optical components and systems for light modulation.
Major tasks include (1) a micro-heterodyne-interferometer
using an unconventional sinusoidal modulation scheme
and a new signal-processing algorithm and (2) High efficiency
electro-optic light modulator based on waveguide-coupled
surface plasmon resonance.
....A new type of heterodyne
interferometry based on a micro-grating mirror which
is modulated in sinusoidal signal is first proposed.
In this study a new algorithm for modulating a micro-grating
mirror using a sine-wave signal instead of a saw-tooth
signal is proposed in order to resolve the flyback problem
in a PZT driver. An improved synthetic heterodyne demodulator
circuit is designed and arranged to interrogate the
output signal from an interferometric sensor with a
sine-wave modulation (phase-generated carrier). As compared
to the conventional technique, modulating the PZT stack
in a saw-tooth signal, this technique supplies a wider
modulated frequency and, therefore, a wider frequency
response in a sensing system. Finally, the new synthetic
heterodyne will be applied to a micro-optics bench as
a micro interferometry.
....The second target
of the proposed study is to design and fabricate a novel
high-efficiency electro-optic (E-O) light modulator
whose operation is based on the attenuated total reflection
(ATR) effect, in which the surface plasmon wave (SPW)
is excited by an incident waveguide-coupled light wave.
The E-O light modulator is fabricated using a non-linear
optical (NLO) polymer. The modulator is characterized,
and its performance tested, in terms of the thickness
and dielectric constant of the polymer thin film, the
E-O coefficient, the insertion loss, and the modulation
index. Additionally, the dynamic response of the E-O
light modulator is fully investigated and discussed.
Also, we demonstrate FM/FDM analog video communication
system using this E-O polymer light modulator as light
....The major focuses
in the second year include:
1. Design and fabrication of microactuators and several
micro mirrors. Several critical micro optical components
have been achieved.
2. Simulation of microactuators
3. Design and fabricate a novel high-efficiency E-O
polymer light modulator. Also, a FM/FDM analog video
communication system is demonstrated by using this E-O
polymer light modulator.