Photo-Polymerized Acrylic Waveguides for Optical Interconnects

ABSTRACTWe have fabricated acrylic based optical channel waveguides using proximity photolithography as well as laser direct writing. The cladding layer is a photosensitive aliphatic urethane dimethacrylate and the guiding layer is a photosensitive aromatic acrylated epoxy. This material system provides good adhesion to a variety of substrate materials. Since both the guiding and cladding layers are applied, these materials can be employed in several electrical/optical applications including multi-chip modules using Si, SiO2, and polyimide as well as high speed electronic board technologies using teflon based substrates.Loss measurements show a guide loss of less than 0.08 dB/cm for multi-mode waveguides fabricated using the direct write laser technique. Lithographically defined guides have a loss of 0.3 dB/cm for similar size waveguides.

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Charged Molten Metal Droplet Deposition as a Direct Write Technology

MRS Proceedings ◽

10.1557/proc-624-17 ◽

2000 ◽

Vol 624 ◽

Cited By ~ 12

Author(s):

M. Orme ◽

J. Courter ◽

Q. Liu ◽

J. Zhu ◽

R. Smith

Keyword(s):

Molten Metal ◽

High Speed ◽

Droplet Diameter ◽

Metal Droplet ◽

Circuit Board ◽

Charged Droplet ◽

Direct Write ◽

Direct Writing ◽

Drop On Demand ◽

Metal Droplets

ABSTRACTThe formation of highly uniform charged molten metal droplets from capillary stream breakup has recently attracted significant industrial and academic interest for applications requiring high-speed and high-precision deposition of molten metal droplets such as direct write technologies. Exploitation of the high droplet production rates intrinsic to the phenomenon of capillary stream break-up and the unparalleled uniformity of droplet sizes and speeds attained with proper applied forcing to the capillary stream make many new applications related to the manufacture of electronic packages, circuit board printing and rapid prototyping of structural components feasible. Recent research results have increased the stream stability with novel acoustic excitation methods and enable ultra-precise charged droplet deflection. Unlike other modes of droplet generation such as Drop-on-Demand, droplets can be generated at rates typically on the order of 10,000 to 20,000 droplets per second (depending on droplet diameter and stream speed) and can be electrostatically charged and deflected onto a substrate with a measured accuracy of ±12.5 µm. Droplets are charged on a drop-to-drop basis, enabling the direct writing of fine details at high speed. New results are presented in which fine detailed patterns are “printed” with individual molten metal solder balls, and issues relevant to the attainment of high quality printed artifacts are investigated.

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Fabrication of Optical Channel Waveguides in the GaAs/AlGaAs System by Mev Ion Beam Bombardment

MRS Proceedings ◽

10.1557/proc-373-457 ◽

1994 ◽

Vol 373 ◽

Cited By ~ 3

Author(s):

T. Taylor ◽

D. Ila ◽

R. L. Zimmerman ◽

P. R. Ashley ◽

D. B. Poker

Keyword(s):

Planar Waveguide ◽

Ion Beam ◽

High Energy ◽

Optical Measurements ◽

Optical Channel ◽

Material System ◽

Optical Confinement ◽

Quantum Well Structures ◽

Oxygen Ions ◽

Channel Waveguides

AbstractWe have fabricated optical channel waveguides in planar GaAs/AlGaAs waveguides using 10 MeV oxygen ions at a fluence of 3x1013 and 3x1014 ions/cm2. Although disordering of GaAs/AlGaAs quantum well structures has previously been reported, to the best of the authors' knowledge the fabrication of channel waveguides using high energy oxygen bombardment has not been demonstrated in this material system. This technique may provide a totally new concept of localized material modifications in GaAs/AlGaAs waveguides by creating compositional disordered regions that act as optical confinement channels. The masking technique used to provide selective disordering of the planar waveguide structures will be presented. Optical measurements were performed on the channel waveguides at a wavelength of 1.3 μm.

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ZnO Channel Waveguides for Nonlinear Optical Applications

Japanese Journal of Applied Physics ◽

10.1143/jjap.49.04dg15 ◽

2010 ◽

Vol 49 (4) ◽

pp. 04DG15 ◽

Cited By ~ 6

Author(s):

Edgar Yoshio Morales Teraoka ◽

Tomohiro Kita ◽

Atsushi Tsukazaki ◽

Masashi Kawasaki ◽

Yasuo Ohtera ◽

...

Keyword(s):

Nonlinear Optical ◽

Channel Waveguides ◽

Optical Applications ◽

Nonlinear Optical Applications

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Closed-form variational effective-index analysis for diffused optical channel waveguides

Journal of the Optical Society of America A ◽

10.1364/josaa.16.002781 ◽

1999 ◽

Vol 16 (11) ◽

pp. 2781 ◽

Cited By ~ 2

Author(s):

Ashmeet Kaur Taneja ◽

Enakshi Khular Sharma

Keyword(s):

Closed Form ◽

Effective Index ◽

Optical Channel ◽

Index Analysis ◽

Channel Waveguides

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Laser ablation of nonlinear-optical polymers to define low-loss optical channel waveguides

Optics Letters ◽

10.1364/ol.19.001840 ◽

1994 ◽

Vol 19 (22) ◽

pp. 1840 ◽

Cited By ~ 5

Author(s):

Joseph C. Chon ◽

Paul B. Comita

Keyword(s):

Laser Ablation ◽

Nonlinear Optical ◽

Optical Channel ◽

Optical Polymers ◽

Low Loss ◽

Nonlinear Optical Polymers ◽

Channel Waveguides

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Ultrathin perpendicular magnetic anisotropy CoFeB free layers for highly efficient, high speed writing in spin-transfer-torque magnetic random access memory

Scientific Reports ◽

10.1038/s41598-019-54466-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Jodi M. Iwata-Harms ◽

Guenole Jan ◽

Santiago Serrano-Guisan ◽

Luc Thomas ◽

Huanlong Liu ◽

...

Keyword(s):

Magnetic Anisotropy ◽

High Speed ◽

Random Access ◽

Perpendicular Magnetic Anisotropy ◽

Spin Transfer Torque ◽

Tunnel Barrier ◽

Magnetic Memory ◽

Material System ◽

Highly Efficient ◽

Memory Applications

AbstractPerpendicular magnetic anisotropy (PMA) ferromagnetic CoFeB with dual MgO interfaces is an attractive material system for realizing magnetic memory applications that require highly efficient, high speed current-induced magnetic switching. Using this structure, a sub-nanometer CoFeB layer has the potential to simultaneously exhibit efficient, high speed switching in accordance with the conservation of spin angular momentum, and high thermal stability owing to the enhanced interfacial PMA that arises from the two CoFeB-MgO interfaces. However, the difficulty in attaining PMA in ultrathin CoFeB layers has imposed the use of thicker CoFeB layers which are incompatible with high speed requirements. In this work, we succeeded in depositing a functional CoFeB layer as thin as five monolayers between two MgO interfaces using magnetron sputtering. Remarkably, the insertion of Mg within the CoFeB gave rise to an ultrathin CoFeB layer with large anisotropy, high saturation magnetization, and good annealing stability to temperatures upwards of 400 °C. When combined with a low resistance-area product MgO tunnel barrier, ultrathin CoFeB magnetic tunnel junctions (MTJs) demonstrate switching voltages below 500 mV at speeds as fast as 1 ns in 30 nm devices, thus opening a new realm of high speed and highly efficient nonvolatile memory applications.

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Processing variables of direct-write, near-field electrospinning impact size and morphology of gelatin fibers

10.1101/2020.09.17.301804 ◽

2020 ◽

Author(s):

Zachary G. Davis ◽

Aasim F. Hussain ◽

Matthew B. Fisher

Keyword(s):

Acetic Acid ◽

Acid Concentration ◽

Near Field ◽

Fiber Formation ◽

Direct Write ◽

Acetic Acid Concentration ◽

Direct Writing ◽

Fiber Morphology ◽

Gelatin Concentration ◽

The Impact

AbstractSeveral biofabrication methods are being investigated to produce scaffolds that can replicate the structure of the extracellular matrix. Direct-write, near-field electrospinning of polymer solutions and melts is one such method which combines fine fiber formation with computer-guided control. Research with such systems has focused primarily on synthetic polymers. To better understand the behavior of biopolymers used for direct-writing, this project investigated changes in fiber morphology, size, and variability caused by varying gelatin and acetic acid concentration, as well as, process parameters such as needle gauge and height, stage speed, and interfiber spacing. Increasing gelatin concentration at a constant acetic acid concentration improved fiber morphology from large, planar structures to small, linear fibers with a median of 2.3 µm. Further varying the acetic acid concentration at a constant gelatin concentration did not alter fiber morphology and diameter throughout the range tested. Varying needle gauge and height further improved the median fiber diameter to below 2 µm and variability of the first and third quartiles to within +/-1 µm of the median for the optimal solution combination of gelatin and acetic acid concentrations. Additional adjustment of stage speed did not impact the fiber morphology or diameter. Repeatable interfiber spacings down to 250 µm were shown to be capable with the system. In summary, this study illustrates the optimization of processing parameters for direct-writing of gelatin to produce fibers on the scale of collagen fibers. This system is thus capable of replicating the fibrous structure of musculoskeletal tissues with biologically relevant materials which will provide a durable platform for the analysis of single cell-fiber interactions to help better understand the impact scaffold materials and dimensions have on cell behavior.

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