ONO2000 Tutorial

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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Optical
Loss
Photothermal Deflection Spectroscopy
convenient for defining mechanisms accounting for
absorption losses. For telecommunication
wavelengths, C-H vibrational overtones usually
dominate.
CLD in APC
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Optical
Loss
It is important to measure optical loss
associated with both absorption and scattering.
Common methods include those of Teng (shown
below) and the cut back method
Optical loss measured for FTC chromophore (max
loading) in PMMA
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Optical
Loss
Mechanisms of Absorption Loss --Interband
electronic absorption --Vibrational
absorption Mechanisms of Scattering
Loss --Material heterogeneity associated with
spin castng --Material heterogeneity associated
with poling -Associated with lattice
hardening -Associated electrophoretic
effect --Material damage associated electric
field poling --Dust particles and foreign
contamination --Optical loss associated with
solvent attack during deposition of cladding
layers --Optical loss from due to cladding
problems --Optical loss associated with reactive
ion etching or photochemical processing
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Lattice
Hardening
Unless a high glass transition polymer is
utilized, lattice hardening must be carried out
to insure adequate thermal stability of the
poling-induced electro-optic activity. On
such lattice hardening scheme is the DEC shown
below
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Thermal
Stability
In thermal stability to 100-120 is adequate,
then a good host is the APC polymer identified
by Lockheed-Martin
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Optical
Loss
The trick to controlling processing losses is to
make sure that the polymer is sufficiently hard
to avoid dielectric breakdown (poling-induced
damage) and damage from the solvent used for
cladding deposition. A hard lattice also helps
to minimize losses in reactive ion etching
(RIE). It is also important to
maintain conditions of a chemical etch (low
kinetic energy of reactive ions). By control of
RIE conditions, excess loss due to RIE
processing can be kept to 0.01 dB/cm. With
control of all processing conditions, waveguide
optical loss can be kept to 1.0 dB/cm. The
greatest source of optical loss associated with
active EO circuits is insertion loss associated
with mode size mismatch between spherical
(approx. 10 mm) silica fiber core and elliptical
(approx. 1-2 micron) core polymeric waveguide.
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Coupling
Loss and Tapered Transitions
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Coupling
Loss and Tapered Transitions
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Optical
Loss
Three dimensional optical circuits and low loss
transition between passive and active waveguides
can be fabricated if vertical transitions can be
produced. The first step is to produce a
vertical slope by shadow, gray scale, or
offset mask techniques. Use of a shadow mask is
shown below.
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Optical
Loss
Processing steps to produce a vertical
transition are shown.
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ONO2000Tutorial
MATERIAL ISSUES Auxiliary Properties--Optical
Loss
A low insertion loss modulator structure is shown.
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ONO2000Tutorial
3-D INTEGRATED OPTICAL CIRCUITS Polarization
Splitter
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ONO2000Tutorial
PROTOTYPE DEVICE EVALUATION Vp
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ONO2000Tutorial
PROTOTYPE DEVICE EVALUATION Vp
Both TACAN and Lockheed-Martin have obtained 1 V
Vp values for push-pull Mach Zehnder modulators.
More typical values for devices such as the
package array below is 2-3 V at telecommunication
wavelengths.
Current Device Vp 2.5 V _at_ 1300 nm 3.7 V _at_
1550 nm Frequency to 60 GHz Temperature Maximum
90C Insertion Loss 5 - 6 dB Extinction ratio
25-30 dB
Latest LiNbO3 (Lucent) Vp 6 V _at_ 1550
nm Frequency to 30 GHz Temperature Max.
70C Insertion loss 6 dB
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ONO2000Tutorial
MATERIAL ISSUES Prototype Device
Evaluation--Bandwidth
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ONO2000Tutorial
MATERIAL ISSUES Prototype Device
Evaluation--Stability
TACAN stability data are given below more data
are needed to evaluate thermal and photochemical
stability.
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ONO2000Tutorial
DEVICES Phased Array Radar and Time Stretching
Two different approaches to phased array radar
including one utilizing the following voltage
controlled RF phase shifter will be discussed.
Also Time Stretching relevant to 100
Gbit/sec analog-to-digital conversion will be
demonstrated.
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ONO2000Tutorial
REPRESENTATIVE RECENT PUBLICATIONS