Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon

Ion-sliced thin-film lithium niobate (LN) compact waveguide technology has facilitated the resurgence of integrated photonics based on lithium niobate. These thin-film LN waveguides offer over an order of magnitude improvement in optical confinement, and about two orders of magnitude reduction in waveguide bending radius, compared to conventional LN waveguides. Harnessing the improved confinement, a variety of miniaturized and efficient photonic devices are demonstrated in this work. First, two types of compact electrooptic modulators are presented – microring modulators, and Mach-Zehnder modulators. Next, two distinct approaches to nonlinear optical frequency converters are implemented – periodically poled lithium niobate, and mode shape modulation (grating assisted quasi-phase matching). Following this, stochastic variations are added to the mode shape modulation approach to demonstrate random quasi-phase matching. Afterward, broadband photon-pair generation is demonstrated in the miniaturized periodically poled lithium niobate, and spectral correlations of the biphoton spectrum are reported. Finally, extensions of the aforementioned results suitable for future work are discussed

Evaluating the acute and chronic toxicity of potassium carbonate and the interactive effects between sodium and potassium on rainbow trout (Oncorhynchus mykiss)

Capture-and-reuse of recirculating aquaculture system (RAS) effluents as hydroponic fertilizer can mitigate the high costs of waste treatment and disposal. However, RAS operators must address limitations in macro- (K, Ca) and micro-nutrients (Fe, Zn, Mo, Cu) and the phytotoxic sodium concentrations (\u3e50 mg/L Na) present in solution. One option is to replace sodium-based pH buffering salts such as sodium bicarbonate with potassium-based derivates such as potassium carbonate or bicarbonate. However, findings in previous studies demonstrate adverse sublethal impacts on fish health due to elevated potassium concentrations. Lethal effects of potassium salts (KCl, KHCO3, and K2SO4) have been demonstrated in fathead minnows (Pimephales promelas) and bluegills (Lepomis macrochirus). Research findings indicate that potassium toxicity in fishes may be mitigated by concentrations of other cations such as sodium, magnesium, and calcium. However, published research on potassium toxicity and interactive effects between sodium and potassium on fish health is limited. The objectives of this research were to determine the acute toxicity of potassium carbonate (K2CO3), the interactive acute toxic effects between two salts (K2CO3 and NaCl), and the chronic toxicity of K2CO3 on growth performance of rainbow trout (Oncorhynchus mykiss) cultured in RAS. The acute toxicity of potassium carbonate (K2CO3) was determined using a median lethal concentration (LC50) study. Five concentrations (707, 1502, 2298, 3093, and 3888 mg/L K2CO3) were tested with ten replicates per treatment. Percent mortality was recorded over a 96-hour period and LC50 concentrations were determined at 24, 48, 72, and 96 hours using Probit regression. Two rounds of preliminary mortality studies with three replicates per treatment were used to determine the interaction between sodium and potassium. The first round of studies tested the effect of K: Na ratio and the second round tested the effects of a balanced (1:1) K: Na ratio using the same potassium concentrations (from K2CO3) used in Experiment 1. Percent mortalities were recorded over a 96-hour period and the results of round two were compared to Experiment 1. A grow-out study was conducted to determine the effects of increased potassium concentrations on the growth performance of rainbow trout. Growth data were collected over 79 days in a replicated study where potassium carbonate was used as the pH buffering salt. Feed conversion ratios (FCRs) and specific growth rates (SGRs) were calculated after the study was concluded. The growth data obtained in this study were compared to growth data obtained in Spring 2018. Median lethal concentrations (LC50) of 3470, 3016, 2831, and 2672 mg/L K2CO3 were obtained at 24, 28, 72, and 96-hours, respectively. However, interactive effects between sodium and potassium on acute toxicity were not observed. In the grow-out study, the SGR was significantly higher (p=0.0093) in the potassium treatment (SGR-1.32 ± 0.02 %/day) than in the control (SGR-0.87 ± 0.06 %/day) and the FCR was significantly lower (p=0.013) in the potassium treatment (FCR-1.18± 0.04) than in the control (FCR-2.96 ± 0.22). The results of this research displayed low acute toxicity to elevated potassium concentrations in rainbow trout. Growth performance was also greater in the potassium treatment than in the control. Furthermore, no interaction between sodium and potassium was demonstrated. This potentially indicates that the replacement of potassium carbonate as the sole buffering salt will not negatively impact fish health. However, there are sources of error including the use of different cohorts and the fluctuations in culture water potassium concentrations. Therefore, another grow-out study should be run using the same cohort of fish reared at the same time under different conditions to obtain a more valid understanding of the effects of elevated potassium on fish health

Beamforming in MISO Systems: Empirical Results and EVM-based Analysis

We present an analytical, simulation, and experimental-based study of beamforming Multiple Input Single Output (MISO) systems. We analyze the performance of beamforming MISO systems taking into account implementation complexity and effects of imperfect channel estimate, delayed feedback, real Radio Frequency (RF) hardware, and imperfect timing synchronization. Our results show that efficient implementation of codebook-based beamforming MISO systems with good performance is feasible in the presence of channel and implementation-induced imperfections. As part of our study we develop a framework for Average Error Vector Magnitude Squared (AEVMS)-based analysis of beamforming MISO systems which facilitates comparison of analytical, simulation, and experimental results on the same scale. In addition, AEVMS allows fair comparison of experimental results obtained from different wireless testbeds. We derive novel expressions for the AEVMS of beamforming MISO systems and show how the AEVMS relates to important system characteristics like the diversity gain, coding gain, and error floor.Comment: Submitted to IEEE Transactions on Wireless Communications, November 200

On-chip optical parametric oscillation into the visible: generating red, orange, yellow, and green from a near-infrared pump

Optical parametric oscillation (OPO) in a microresonator is promising as an efficient and scalable approach to on-chip coherent visible light generation. However, so far only red light at < 420 THz (near the edge of the visible band) has been reported. In this work, we demonstrate on-chip OPO covering > 130 THz of the visible spectrum, including red, orange, yellow, and green wavelengths. In particular, using a pump laser that is scanned 5 THz in the near-infrared from 386 THz to 391 THz, the signal is tuned from the near-infrared at 395 THz to the visible at 528 THz, while the idler is tuned from the near-infrared at 378 THz to the infrared at 254 THz. The widest signal-idler separation we demonstrate of 274 THz corresponds to more than an octave span and is the widest demonstrated for a nanophotonic OPO to date. Our work is a clear demonstration of how nonlinear nanophotonics can transform light from readily accessible compact near-infrared lasers to targeted visible wavelengths of interest, which is crucial for field-level deployment of spectroscopy and metrology systems.Comment: 6 pages, 5 figure

Abnormal muscle in the anterior compartment of the forearm: a case report

During routine dissection for the undergraduate medical students, we encountered an unusual, additional muscle in the anterior compartment of the forearm. This muscle took origin from the anterior surface of the radius in common with the flexor digitorum superficialis muscle. It had a tendon of origin and a tendon of insertion. Its fleshy radial belly and the tendon of insertion, crossed superficial to the median nerve. The muscle was inserted partly to the flexor retinaculum and partly to the undersurface of palmar aponeurosis. The observations made by us in the present case will supplement our knowledge of variations of the muscles in this region which could be useful for hand surgeons as it could possibly compress the median nerve because of its close relationship to it

A universal frequency engineering tool for microcavity nonlinear optics: multiple selective mode splitting of whispering-gallery resonances

Whispering-gallery microcavities have been used to realize a variety of efficient parametric nonlinear optical processes through the enhanced light-matter interaction brought about by supporting multiple high quality factor and small modal volume resonances. Critical to such studies is the ability to control the relative frequencies of the cavity modes, so that frequency matching is achieved to satisfy energy conservation. Typically this is done by tailoring the resonator cross-section. Doing so modifies the frequencies of all of the cavity modes, that is, the global dispersion profile, which may be undesired, for example, in introducing competing nonlinear processes.Here, we demonstrate a frequency engineering tool, termed multiple selective mode splitting (MSMS), that is independent of the global dispersion and instead allows targeted and independent control of the frequencies of multiple cavity modes. In particular, we show controllable frequency shifts up to 0.8 nm, independent control of the splitting of up to five cavity modes with optical quality factors $\gtrsim 10^5$, and strongly suppressed frequency shifts for untargeted modes. The MSMS technique can be broadly applied to a wide variety of nonlinear optical processes across different material platforms, and can be used to both selectively enhance processes of interestand suppress competing unwanted processes.Comment: 13 pages, 8 figure

A Countdown to Orthognathic Surgery

For patients whose orthodontic problems are so severe that&nbsp;neither growth modification nor camouflage offers a solution,&nbsp;surgery to realign the jaws or reposition dentoalveolar segments&nbsp;is the only possible treatment. Surgery is not a substitute for&nbsp;orthodontics in these patients. Instead, it must be properly&nbsp;coordinated with orthodontics and other dental treatment to&nbsp;achieve good overall results

STABILITY INDICATING RP-HPLC METHOD FOR THE ESTIMATION OF QUETIAPINE FUMARATE IN BULK AS WELL AS IN PHARMACEUTICAL DOSAGE FORM

This study was designed to develop and validate a simple, sensitive, precise, and specific stability indicating reverse phase high-performance liquid chromatographic (HPLC) method for estimation of Quetiapine Fumarate in bulk and its tablet dosage form. The HPLC separation was carried out by reverse phase chromatography on Thermo column Symmetry C18 (4.6 x 150mm, 5 mm) with a mobile phase composed Sodium dihydrogen phosphate and the pH was adjusted to 4.0 by Orthophosporic Acid &amp; Methanol in the ratio of 35:65 v/v in isocratic mode at a flow rate of 1.0 ml/min. The run time was maintained for 6mins. The detection was monitored at 290 nm. The calibration curve for Quetiapine Fumarate was linear from 20 to60 µg/ml. The inter-day and intra-day precision was found to be within the limits. The proposed method was adequate sensitivity, reproducibility, and specificity for the determination of Quetiapine Fumarate in bulk and its tablet dosage forms. The limit of detection [LOD] and limit of quantification [LOQ] for Quetiapine Fumarate were found to be 0.01 µg/ml and 0.03 µg /ml respectively. The Accuracy recoveries were 100.0-100.4% and reproducibility was found to be satisfactory. The bulk active pharmaceutical ingredient was subjected to  thermal,  photolytic,  hydrolytic  (acidic  and  basic)  and  oxidative  stress  conditions  and  stressed  samples  were analyzed by the proposed method. The method was validated in terms of linearity, precision, accuracy, specificity and robustness. All the validation was done as per ICH guidelines. The proposed method was simple, fast, accurate, and precise for the quantification of Quetiapine Fumarate in the dosage form, bulk drugs as well as for routine analysis in quality control. Key-Words: Quetiapine Fumarate, RP-HPLC, ICH, Stability Indicating Studies, LOD, LOQ