MATERIAL ISSUES: Auxiliary Properties--Optical Loss ONO2000 Tutorial Photothermal Deflection Spectroscopy convenient for defining mechanisms accounting for absorption losses. For telecommunication wavelengths, C-H vibrational overtones usually dominate. CLD in APC

MATERIAL ISSUES: Auxiliary Properties--Optical Loss ONO2000 Tutorial 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

MATERIAL ISSUES: Auxiliary Properties--Optical Loss ONO2000 Tutorial 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

MATERIAL ISSUES: Auxiliary Properties--Lattice Hardening ONO2000 Tutorial 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

MATERIAL ISSUES: Auxiliary Properties--Thermal Stability ONO2000 Tutorial In thermal stability to is adequate, then a good host is the APC polymer identified by Lockheed-Martin

MATERIAL ISSUES: Auxiliary Properties--Optical Loss ONO2000 Tutorial 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  m) silica fiber core and elliptical (approx. 1-2 micron) core polymeric waveguide.

MATERIAL ISSUES: Auxiliary Properties--Coupling Loss and Tapered Transitions ONO2000 Tutorial

MATERIAL ISSUES: Auxiliary Properties--Coupling Loss and Tapered Transitions ONO2000 Tutorial

MATERIAL ISSUES: Auxiliary Properties--Optical Loss ONO2000 Tutorial 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.

MATERIAL ISSUES: Auxiliary Properties--Optical Loss ONO2000 Tutorial Processing steps to produce a vertical transition are shown.

MATERIAL ISSUES: Auxiliary Properties--Optical Loss ONO2000 Tutorial A low insertion loss modulator structure is shown.

3-D INTEGRATED OPTICAL CIRCUITS: Polarization Splitter ONO2000 Tutorial

PROTOTYPE DEVICE EVALUATION: V  ONO2000 Tutorial

PROTOTYPE DEVICE EVALUATION: V  ONO2000 Tutorial Both TACAN and Lockheed-Martin have obtained 1 V V  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 V  = nm ; nm Frequency to ~ 60 GHz Temperature Maximum ~90°C Insertion Loss dB Extinction ratio dB Latest LiNbO 3 (Lucent) V  = nm Frequency to 30 GHz Temperature Max. 70°C Insertion loss 6 dB

MATERIAL ISSUES: Prototype Device Evaluation--Bandwidth ONO2000 Tutorial

MATERIAL ISSUES: Prototype Device Evaluation--Stability ONO2000 Tutorial TACAN stability data are given below; more data are needed to evaluate thermal and photochemical stability.

DEVICES: Phased Array Radar and Time Stretching ONO2000 Tutorial 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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