Low Cost Method for Generating Periodic Nanostructures by Interference Lithography Without the Use of an Anti-Reflection Coating

MRS Advances ◽  
2017 ◽  
Vol 2 (17) ◽  
pp. 927-932
Author(s):  
Omree Kapon ◽  
Merav Muallem ◽  
Alex Palatnik ◽  
Hagit Aviv ◽  
Yaakov. R. Tischler
Keyword(s):  
Laser Light ◽  
Low Cost ◽  
Single Mode ◽  
Interference Lithography ◽  
Silicon Substrates ◽  
High Fidelity ◽  
Periodic Nanostructures ◽  
Positive Photoresist ◽  
Quarter Wavelength ◽  
Ammonium Dichromate

ABSTRACTInterference lithography has proven to be a useful technique for generating periodic sub-diffraction limited nanostructures. Interference lithography can be implemented by exposing a photoresist polymer to laser light using a two-beam arrangement or a one-beam configuration based on a Lloyd’s Mirror Interferometer. For typical photoresist layers, an anti-reflection coating must be deposited on the substrate to prevent adverse reflections from cancelling the holographic pattern of the interfering beams. For silicon substrates, such coatings are typically multilayered and complex in composition. By thinning the photoresist layer to a thickness well below the quarter wavelength of the exposing beam, we demonstrate that interference gratings can be generated without an anti-reflection coating on the substrate. We used ammonium dichromate doped polyvinyl alcohol as the positive photoresist because it provides excellent pinhole free layers down to thicknesses of 40 nm, and can be cross-linked by a low-cost single mode 457 nm laser and etched in water. Gratings with a period of 320 nm and depth of 4 nm were realized, as well as a variety of morphologies depending on the photoresist thickness. This simplified interference lithography technique promises to be useful for generating periodic nanostructures with high fidelity and minimal substrate treatments.

Deep nulling of laser light with a single-mode-fiber beam combiner

2006 ◽  
Vol 45 (12) ◽  
pp. 2749 ◽  
Author(s):  
Pierre Haguenauer ◽  
Eugene Serabyn
Keyword(s):  
Laser Light ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Beam Combiner

Measuring Optical Properties of Advanced Nano/Micro-Periodic Structures Fabricated by Multi-Exposure Interference Lithography

2020 ◽  
Author(s):  
Shuzo Masui ◽  
Masaki Michihata ◽  
Kiyoshi Takamasu ◽  
Satoru Takahashi
Keyword(s):  
Periodic Structures ◽  
Low Cost ◽  
Industrial Applications ◽  
Interference Lithography ◽  
High Dispersion ◽  
Optical Elements ◽  
Precise Control ◽  
Periodic Grating ◽  
Interference Fringes ◽  
Multiple Interference

Abstract Functional optical elements based on nano/micro-periodic structures have attracted much attention. Since the fabrication of these dual-periodic structures requires precise control of periodicity, the semiconductor process such as an electron beam lithography has been mainly employed. However, these techniques have problems with expensive and low throughput for industrial applications. Therefore, there remains a need for low cost and high throughput fabrication methods of dual-periodic structures. Then we developed a multi-exposure interference lithography (MEIL) system using rotational Lloyd’s mirror interferometer to overcome these problems. The advantages of interference lithography are a large processing area and low cost. Our developed rotational Lloyd’s mirror setup enables us to a highly precise superposition of multiple interference fringes by multi-exposure. Furthermore, we developed a measurement setup for reflective diffractive elements using a two axial rotating stage and measured the diffraction properties of the fabricated dual-periodic diffraction gratings. In this paper, as a demonstration, we succeeded in the fabrication of high-dispersion diffraction grating with an enhanced diffraction efficiency of the −3rd order light. The fabricated shapes have a periodicity of 1997 nm and 665 nm. Furthermore, it was confirmed that the intensity of the −3rd order light was enhanced by about 10 times compared to the single periodic grating.

Switchable and tunable linear cavity erbium-doped fiber laser based on FBGs embedded in Sagnac rings

Laser Physics ◽  
2021 ◽  
Vol 32 (1) ◽  
pp. 015101
Author(s):  
Gangxiao Yan ◽  
Weihua Zhang ◽  
Peng Li ◽  
Qiuhao Jiang ◽  
Meng Wu ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Low Cost ◽  
Single Mode ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Hole Burning ◽  
Linear Cavity ◽  
Erbium Doped ◽  
Optical Fiber Sensing ◽  
Birefringence Effect

Abstract A switchable and tunable erbium-doped fiber laser with a linear cavity based on fiber Bragg gratings embedded in Sagnac rings is proposed and experimentally verified. Due to the stress birefringence effect and the polarized hole burning effect, which are introduced into the single-mode fiber in the polarization controllers (PCs) by the PCs, the designed laser can achieve seven kinds of laser-states output including three kinds of single-wavelength laser states, three kinds of dual-wavelength laser states and one kind of triple-wavelength laser state. The optical signal-to-noise ratios of the output wavelengths are all higher than 52 dB, and the wavelength shifts are all less than 0.04 nm. Furthermore, the temperature tuning of the wavelength range is also researched, which is about 1.2 nm. Due to advantages, such as low cost, simple structure, easy switching and multiple laser states, the designed laser has great application potential in laser radar, optical fiber sensing and so on.

scholarly journals Analysis of Curvature in Fiber Optic Cable for Macrobending-Based Slope Sensor

2021 ◽  
Vol 3 (1) ◽  
pp. 45-56
Author(s):  
Imam Mulyanto
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Laser Intensity ◽  
Single Mode ◽  
Power Losses ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Working Principle

The analysis of fiber optics for macro bending-based slope sensors using SMF-28 single-mode optical fibers has been successfully conducted. Fiber optics were treated to silicon rubber molding and connected with laser light and power meters to measure the intensity of laser power generated. The working principle was carried out using the macrobending phenomenon on single-mode optical fibers. The intensity of laser light in fiber optic cables decreases in the event of indentation or bending of the fiber optic cable. Power losses resulting from the macrobending process can be seen in the result of the information sensitivity of fiber optics to the change of angle given. From the results of the study, the resulting fiber optic sensitivity value is -0.1534o/dBm. The larger the angle given, the lower the laser intensity received by the power meter.

scholarly journals Closed-loop ring resonator topology for bandpass filter applications

2020 ◽  
Vol 17 (3) ◽  
pp. 1422
Author(s):  
Norfishah Ab Wahab ◽  
M. N. Md Tan ◽  
M. N. Hushim
Keyword(s):  
Transmission Lines ◽  
Closed Loop ◽  
Bandpass Filter ◽  
Ring Resonator ◽  
Single Mode ◽  
Ring Structure ◽  
Transmission Zeros ◽  
Quarter Wavelength ◽  
Coupled Lines ◽  
Loop Ring

<p class="Pa41">This paper presents a single mode pseudo-elliptic bandpass resonator based on closed-loop ring topology. The resonator is built from six quarter wavelength transmission lines to form a square closed-loop ring structure. This structure creates transmission zeros at the lower and upper sidebands so that high selectivity bandpass filter response is achieved. The advantage of this topology is that the design is less complex since no perturbation is needed on the ring lines for creation of transmission zeros. Higher-order filters can be constructed by introducing quarter-wavelength coupled-lines, coupled at both input and output of the closed-loop ring resonator. For proof of concept, the filters are designed at 10 GHz up to 3<sup>rd</sup> order, simulated using full-wave electromagnetic simulator on microstrip substrate, <em>FR-4</em> with characteristics given as <em>Ԑr </em>= 4.70, <em>h </em>= 1.499 mm and <em>tan δ </em>= 0.012.  The filters are simulated and responses are found to be agreeable with the proposed idea.</p>

scholarly journals Improving Learners' Comfort With Cesarean Sections Through the Use of High-Fidelity, Low-Cost Simulation

MedEdPORTAL ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Tatiana Acosta ◽  
Jill Marie Sutton ◽  
Sarah Dotters-Katz
Keyword(s):  
Low Cost ◽  
High Fidelity ◽  
Cesarean Sections ◽  
Cost Simulation

scholarly journals Novel Neonatal Simulator Provides High-Fidelity Ventilation Training Comparable to Real-Life Newborn Ventilation

Children ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 940
Author(s):  
Joanna Haynes ◽  
Peder Bjorland ◽  
Øystein Gomo ◽  
Anastasia Ushakova ◽  
Siren Rettedal ◽  
...  
Keyword(s):  
Skill Acquisition ◽  
Low Cost ◽  
Negative Relationship ◽  
Real Life ◽  
Neonatal Resuscitation ◽  
Healthcare Personnel ◽  
Positive Pressure ◽  
High Fidelity ◽  
High Resource ◽  
Clinical Conditions

Face mask ventilation of apnoeic neonates is an essential skill. However, many non-paediatric healthcare personnel (HCP) in high-resource childbirth facilities receive little hands-on real-life practice. Simulation training aims to bridge this gap by enabling skill acquisition and maintenance. Success may rely on how closely a simulator mimics the clinical conditions faced by HCPs during neonatal resuscitation. Using a novel, low-cost, high-fidelity simulator designed to train newborn ventilation skills, we compared objective measures of ventilation derived from the new manikin and from real newborns, both ventilated by the same group of experienced paediatricians. Simulated and clinical ventilation sequences were paired according to similar duration of ventilation required to achieve success. We found consistencies between manikin and neonatal positive pressure ventilation (PPV) in generated peak inflating pressure (PIP), mask leak and comparable expired tidal volume (eVT), but positive end-expiratory pressure (PEEP) was lower in manikin ventilation. Correlations between PIP, eVT and leak followed a consistent pattern for manikin and neonatal PPV, with a negative relationship between eVT and leak being the only significant correlation. Airway obstruction occurred with the same frequency in the manikin and newborns. These findings support the fidelity of the manikin in simulating clinical conditions encountered during real newborn ventilation. Two limitations of the simulator provide focus for further improvements.

scholarly journals A novel, low-cost, reusable, high-fidelity neurosurgical training simulator for cerebrovascular bypass surgery

2019 ◽  
Vol 130 (5) ◽  
pp. 1663-1671
Author(s):  
Ulas Cikla ◽  
Balkan Sahin ◽  
Sahin Hanalioglu ◽  
Azam S. Ahmed ◽  
David Niemann ◽  
...  
Keyword(s):  
Bypass Surgery ◽  
Low Cost ◽  
Artery Bypass ◽  
Superficial Temporal Artery ◽  
Temporal Artery ◽  
High Fidelity ◽  
Skin Closure ◽  
Neurosurgical Training ◽  
Training Simulator ◽  
Live Animal

OBJECTIVECerebrovascular bypass surgery is a challenging yet important neurosurgical procedure that is performed to restore circulation in the treatment of carotid occlusive diseases, giant/complex aneurysms, and skull base tumors. It requires advanced microsurgical skills and dedicated training in microsurgical techniques. Most available training tools, however, either lack the realism of the actual bypass surgery (e.g., artificial vessel, chicken wing models) or require special facilities and regulations (e.g., cadaver, live animal, placenta models). The aim of the present study was to design a readily accessible, realistic, easy-to-build, reusable, and high-fidelity simulator to train neurosurgeons or trainees on vascular anastomosis techniques even in the operating room.METHODSThe authors used an anatomical skull and brain model, artificial vessels, and a water pump to simulate both extracranial and intracranial circulations. They demonstrated the step-by-step preparation of the bypass simulator using readily available and affordable equipment and consumables.RESULTSAll necessary steps of a superficial temporal artery–middle cerebral artery bypass surgery (from skin opening to skin closure) were performed on the simulator under a surgical microscope. The simulator was used by both experienced neurosurgeons and trainees. Feedback survey results from the participants of the microsurgery course suggested that the model is superior to existing microanastomosis training kits in simulating real surgery conditions (e.g., depth, blood flow, anatomical constraints) and holds promise for widespread use in neurosurgical training.CONCLUSIONSWith no requirement for specialized laboratory facilities and regulations, this novel, low-cost, reusable, high-fidelity simulator can be readily constructed and used for neurosurgical training with various scenarios and modifications.

Solution-processed whispering-gallery-mode microsphere lasers based on colloidal CsPbBr3 perovskite nanocrystals

2021 ◽  
Author(s):  
Minghong Xie ◽  
Wenxiao Gong ◽  
Lei Kong ◽  
Yang Liu ◽  
Yang Mi ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Single Mode ◽  
Whispering Gallery Mode ◽  
Solution Processed ◽  
Time Resolved ◽  
Perovskite Nanocrystals ◽  
Whispering Gallery ◽  
Low Threshold ◽  
The Stability

Abstract Perovskite nanocrystals (NCs) have emerged as attractive gain materials for solution-processed microlasers. Despite the recent surge of reports in this feld, it is still challenging to develop low-cost perovskite NCbased microlasers with high performance. Herein, we demonstrate low-threshold, spectrally tunable lasing from ensembles of CsPbBr3 NCs deposited on silica microspheres. Multiple whispering-gallery-mode lasing is achieved from individual NC/microspheres with a low threshold of ∼3.1 µJ cm−2 and cavity quality factor of ∼1193. Through time-resolved photoluminescence measurements, electron-hole plasma recombination is elucidated as the lasing mechanism. By tuning the microsphere diameter, the desirable single-mode lasing is successfully achieved. Remarkably, the CsPbBr3 NCs display durable room-temperature lasing under ∼107 shots of pulsed laser excitation, substantially exceeding the stability of conventional colloidal NCs. These CsPbBr3 NC-based microlasers can be potentially useful in photonic applications.

XPS Jensen Lung as a Low-Cost, High-Fidelity Training Adjunct to Ex-Vivo Lung Perfusion

2018 ◽  
Vol 37 (4) ◽  
pp. S243-S244
Author(s):  
B. Shukrallah ◽  
C. Eggeman ◽  
D. Mast ◽  
D. Igoe ◽  
J. Ralston ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Low Cost ◽  
Lung Perfusion ◽  
High Fidelity ◽  
Ex Vivo Lung Perfusion
Sign in / Sign up

Export Citation Format

Share Document