Long term stable, synchronizable, low noise picosecond Ho:fiber NALM oscillator for Ho:YLF amplifier seeding

2022 ◽  
Author(s):  
Christoph Mahnke ◽  
Yi Hua ◽  
Yuxuan Ma ◽  
Haydar Salman ◽  
Thorsten Lamb ◽  
...  
Keyword(s):  
1974 ◽  
Vol 20 (8) ◽  
pp. 1009-1012 ◽  
Author(s):  
Robert L Berger ◽  
Walter S Friauf ◽  
Horace E Cascio

Abstract A precision thermistor bridge and thermistor is described for use in a thermal titration calorimeter or a high-speed stopped- or continuous-flow calorimeter of the Roughton type. These are compared and evaluated with regard to several other types of detectors, including the platinum resistance thermometer, thermocouple, transistor thermometer, and capacitance thermometers. At this time the best detection for our purpose seems to be a specially constructed 20-100 kΩ thermistor used in conjunction with a new ac lock-in amplifier bridge. The sensitivity of the system is equivalent to a peak-to-peak noise of 25 x 10-6 °C, with a 100-ms time constant and 1 µW power dissipation in the thermistor. Long-term drift of the bridge, without an oven, was 1 x 10-6 °C/min.


Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2592 ◽  
Author(s):  
Marek Przyborski ◽  
Jerzy Pyrchla ◽  
Krzysztof Pyrchla ◽  
Jakub Szulwic

The article discusses the registration of micro-gravity changes with the MGS-6 Micro-g LaCoste gravity sensor during static measurements. An experiment was carried out to determine how small changes in gravity can be registered using the MGS-6 system sensor. The tides of the Earth’s crust were chosen as the source of disturbance of the field with small amplitude and long-term changes. The tested sensor was placed in a geophysical observatory on a specially designed tripod. Simultaneously on the nearby concrete pillar, the registration of changes in gravity was carried out using the superconducting iGrav gravimeter. The high temporal stability of the superconducting gravimeters and the low noise combined with leading sensitivity of its reading allow it to be considered as a reliable reference source for MGS-6. The article discusses the impact of non-leveling changes of the MGS-6 gravimetry on the reading and determines the size of its non-linear drift. The obtained differences in indications between devices did not exceed 50 μ Gal for 68% of data. The measurements also showed excellent time stability of the MGS-6 measurement system. The data collected during the experiment allowed determining the level of accuracy that can be sought during real measurements using the MGS-6 system on research vessels. They also give an overview of the dynamics of the drift phenomenon of the analyzed research system.


Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 278-294 ◽  
Author(s):  
Harold Barker ◽  
Richard Burleigh ◽  
Nigel Meeks

Dates listed below are based on measurements made up to May 1968, and cover a period during which the technique of gas proportional counting using CO2 was gradually replaced by liquid scintillation counting using benzene. The gas counting measurements were carried out by the method and techniques previously described (Barker and Mackey, 1968) the only modifications being the replacement of some old electronic units by more stable solid-state equipment; proportional counting results are indicated in the text by (P) at the end of the relevant sample descriptions. Liquid scintillation counting, which is now the preferred method in this laboratory, is carried out using a Packard Tri-Carb liquid scintillation spectrometer model 3315/AES fitted with selected low-noise quartz-faced photomultipliers. Normally 3 ml of benzene is prepared from each sample. This is dissolved in 12 ml of scintillation grade toluene containing 5 gm/liter of scintillator (PPO) and the solution is measured in a standard low-potassium glass vial at a temperature of 0°C. Photomultiplier E.H.T., amplifier, and channel width settings are optimized for C14, and measurements are carried out at ca. 65% efficiency of detection for C14 to eliminate interference from any tritium which may be present in the benzene. Under these circumstances the background is approx. 8.6 cpm and the modern (95% Aox) is approx. 24.0 cpm. Samples are counted in groups of 3 to 5 together with background and modern reference samples and are measured for at least one week, the instrument being set to cycle at 100 min intervals. In this period, the counts accumulated are such that the background is always measured to a statistical accuracy of better than 1% and most other samples to a higher accuracy than this. Background and modern counts used in the calculation of each result are only those relevant to the period of measurement of that particular sample. Statistical analysis of groups of replicate measurements made under these conditions over a very long period of time has demonstrated the excellent long-term stability of the equipment and indicates that the technique is quite capable of achieving results of very high statistical accuracy when required.


Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3379 ◽  
Author(s):  
Caterina Travan ◽  
Alexander Bergmann

Graphene is a good candidate for filling the market requirements for cheap, high sensitivity, robust towards contamination, low noise, and low power consumption gas sensors, thanks to its unique properties, i.e., large surface, high mobility, and long-term stability. Inkjet printing is a cheap additive manufacturing method allowing fast, relatively precise and contactless deposition of a wide range of materials; it can be considered therefore the ideal technique for fast deposition of graphene films on thin substrates. In this paper, the sensitivity of graphene-based chemiresistor gas sensors, fabricated through inkjet printing, is investigated using different concentrations of graphene in the inks. Samples have been produced and characterized in terms of response towards humidity, nitrogen dioxide, and ammonia. The presented results highlight the importance of tuning the layer thickness and achieving good film homogeneity in order to maximize the sensitivity of the sensor.


Instruments ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 2 ◽  
Author(s):  
Christopher Bosyj ◽  
Neelesh Bhadwal ◽  
Thomas Coyle ◽  
Anthony Sinclair

Long-term installation of ultrasonic transducers in high temperature environments allows for continuous monitoring of critical components and processes without the need to halt industrial operations. Transducer designs based on the high-Curie-point piezoelectric material lithium niobate have been shown to both be effective and stable at extreme temperatures for long-term installation. In this study, several brazing techniques are evaluated, all of which aim to provide both mechanical bonding and acoustic coupling directly to a bare lithium niobate piezoelectric element. Two brazing materials—a novel silver-copper braze applied in a reactive air environment and an aluminum-based braze applied in a vacuum environment—are found to be suitable for ultrasound transmission at elevated temperatures. Reliable wide-bandwidth and low-noise ultrasound transmission is achieved between room temperature and 800 °C.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Grzegorz Szczepkowski ◽  
Ronan Farrell

This paper presents a study of linearity in wideband CMOS low noise amplifiers (LNA) and its relationship to power consumption in context of Long Term Evolution (LTE) systems and its future developments. Using proposed figure of merit (FoM) to compare 35 state-of-the-art LNA circuits published over the last decade, the paper explores a dependence between amplifier performance (i.e., combined linearity, noise figure, and gain) and power consumption. In order to satisfy stringent linearity specifications for LTE standard (and its likely successors), the paper predicts that LNA FoM increase in the range of +0.2 dB/mW is expected and will inevitably translate into a significant increase in power consumption—a critical budget planning aspect for handheld devices, active antenna arrays, and base stations operating in small cells.


1957 ◽  
Vol 35 (3) ◽  
pp. 258-270 ◽  
Author(s):  
B. G. Harvey ◽  
H. G. Jackson ◽  
T. A. Eastwood ◽  
G. C. Hanna

The α-particle energies of U234, U238, and Th232 have been measured with a grid ionization chamber. The electronic equipment was designed to provide low noise, high resolution, and good long term stability. Ra226, Em222, Po218, Po214, and Po210 were used as energy standards. An investigation was made of the corrections to the measurements due to variation in pulse rise-time, source thickness, and imperfect shielding of the collector by the grid. It was found that the experimentally observed resolution was satisfactorily accounted for by the combination of these factors and the noise and ionization straggling.Alpha particle pulse heights were measured in terms of the output of a precision pulse generator. The corrected pulse heights were related to the energies of the standard sources by a two-parameter least squares calculation; the standard deviation was never greater than 5 kev. On extrapolating to zero ionization the line so obtained intercepted the energy axis at 83 kev. The α-particle energies deduced using this line were: U234 4.768 ± 0.003, U238 4.195 ± 0.005, Th232 4.007 ± 0.005 Mev.


Author(s):  
Abu Bakar Ibrahim ◽  
Nurul Husna Abdul Kahar ◽  
Hafizul Fahri Hanafi ◽  
Ashardi Abas ◽  
Shamsul Arrieya Ariffin

The paper aims to develop a new cascode low noise amplifier (LNA) by using double feedback technique architecture for wireless communication especially for long term evolution (LTE). The objective of this article is to display the improved performance of gain by minimizing noise figures with innovative techniques for the realization of Long Term Evolution (LTE). The innovation technique with implementation double feedback technique architecture outlines the possibility to improve the performance in various parameters such as bandwidth, stability, gain, noise figure, power consumption and complexity. The realization using cascode LNA is verified by using FHX76LP Super Low Noise HEMT that operate at 5.8 GHz in compliant with LTE standard. The Advance Design System (ADS) software is used to obtain characteristics for collecting data in a smith chart and s-parameter generated by simulation. The cascode LNA with the double feedback technique achieves an average gain of 20.887 dB with a noise figure of 0.341 dB. The input return loss and output return loss are – 14.354 dB and – 11.879 dB respectively. The outcome of this work will contribute to providing a better wireless signal receiver especially for the LTE standard and it potentially addressing wireless communication issues in rural areas.


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