scholarly journals A perspective on high photon flux nonclassical light and applications in nonlinear optics

2020 ◽  
Vol 8 ◽  
Author(s):  
Th. Lamprou ◽  
I. Liontos ◽  
N. C. Papadakis ◽  
P. Tzallas

Abstract Nonclassical light sources have a vital role in quantum optics as they offer a unique resource for studies in quantum technology. However, their applicability is restricted by their low intensity, while the development of new schemes producing intense nonclassical light is a challenging task. In this perspective article, we discuss potential schemes that could be used towards the development of high photon flux nonclassical light sources and their future prospects in nonlinear optics.

Agronomy ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 207 ◽  
Author(s):  
Hao Wei ◽  
Jiangtao Hu ◽  
Chen Liu ◽  
Mengzhao Wang ◽  
Jin Zhao ◽  
...  

Supplementary lighting is commonly used in high-quality seedling production. In this study, grafted tomato seedlings were grown for 10 days in a glasshouse with 16-h daily supplementary lighting at 100 μmol·m−2·s−1 PPFD (Photosynthetic photon flux density) from either high-pressure sodium (HPS), metal halide (MH), far-red (FR), white LEDs (Light emitting diodes) (W), or mixed LEDs (W1R2B1, where the subscript numbers indicate the ratio of the LED chips) to determine which light sources improve the seedling quality. The control seedlings did not receive any supplementary light. Physiological parameters and the expression of genes related to photosynthesis were analyzed. The results showed that root length, biomass, number of leaves, chlorophyll (SPAD), scion dry weight to height ratio (WHR), and specific leaf weight (SLW) were the greatest for grafted seedlings grown in W1R2B1. The level of root ball formation was the greatest for seedlings grown in W1R2B1, followed by those grown in W, HPS, and MH. Seedlings grown in FR did not fare well, as they were very thin and weak. Moreover, the expression of two photosynthetic genes (PsaA and PsbA) was significantly increased by W1R2B1 and W, which suggests that the plastid or nuclear genes might be regulated. The overall results suggest that W1R2B1 was the most suitable light source to enhance the quality of grafted tomato seedlings. The results of this study could be used as a reference for seedling production in glasshouses, and may provide new insights in the research on lights affecting the development of plants.


2019 ◽  
Vol 184 (Supplement_1) ◽  
pp. 593-603 ◽  
Author(s):  
Michael D Reddix ◽  
Matthew E Funke ◽  
Micah J Kinney ◽  
John L Bradley ◽  
Greg Irvin ◽  
...  

Abstract Prototype low-intensity threat laser eye protection (LIT-LEP) spectacles were evaluated for US Coast Guard (USCG) cockpits and night vision goggle compatibility. The impetus for interest in aviation LIT-LEP is driven in part by the fact that easily accessible 0.5–2.0 W high-power laser pointers exceed safety standards for direct on-axis viewing. A repeated-measures experimental design was used to assess LIT-LEP performance relative to a no-LEP control for the following tasks: Near- and far contrast acuity, night vision goggle far-contrast acuity, emissive and non-emissive light source color-vision screening, and USCG multifunctional display color symbol discrimination reaction time and accuracy. Near- and far-contrast acuity results demonstrated good LIT-LEP performance for typical in- and out-of-cockpit lighting conditions. Night vision goggle performance suffered marginally at only one contrast level (85%; 20/30 acuity line). Color vision test results showed good color balance in that S-, M-, and L-cone performance did not demonstrate a clinical diagnostic color defect for emissive or non-emissive light sources when wearing LIT-LEP. Color symbol discrimination reaction-time-task results based on inverse efficiency scores revealed that some non-primary flight display colors exhibited a combination of slower speed and decreased accuracy. The findings will contribute to an acquisition decision as well as guide future LEP designs.


Author(s):  
Dr. R. Thillaikkarasi ◽  
Sindhuja R ◽  
Sivabharati M ◽  
Abira Bright ◽  
Sreejith V

Optics has, since ancient times, being used as aid for the exam human patients and in some therapeutic treatments. Many of the optic medical instruments in use today were developed in the nineteenth century and, with the advent of optical fibers and laser light sources in the mid twentieth century, a new generation of medical devices, instruments, and techniques have been developed that have helped modernize medicine and perform task unimaginable only a few decades ago. This chapter illustrates through several optical instrument and application examples the uses, benefits, and future prospects that optics brings as an enabling technology to the medicine and the overall healthcare industry.


2021 ◽  
Vol 30 (3) ◽  
pp. 8-12
Author(s):  
Jae Hoon LEE ◽  
Hyojun SEOK

Quantum measurements with atoms have been at the forefront of quantum technology and provide crucial information for a better understanding of quantum physics ever since their conception over a century ago. The universality of the quantized energy states of atoms makes the collective state of an atomic ensemble an outstanding platform for quantum-enhanced metrology. We introduce basic concepts regarding the metrological gain acquired from using nonclassical quantum states via multiparticle entanglement. Current challenges and future prospects for further enhancement of the measurement sensitivity through the use of nonclassical atomic states are discussed with reference to the shot noise and Heisenberg limits.


Author(s):  
Alexander Kirsche ◽  
Robert Klas ◽  
Martin Gebhardt ◽  
Lucas Eisenbach ◽  
Wilhelm Eschen ◽  
...  

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 870 ◽  
Author(s):  
Filippos Bantis ◽  
Athanasios Koukounaras ◽  
Anastasios S. Siomos ◽  
Kalliopi Radoglou ◽  
Christodoulos Dangitsis

Watermelon is cultivated worldwide and is mainly grafted onto interspecific squash rootstocks. Light-emitting diodes (LEDs) can be implemented as light sources during indoor production of both species and their spectral quality is of great importance. The objective of the present study was to determine the optimal emission of LEDs with wide wavelength for the production of watermelon and interspecific squash seedlings in a growth chamber. Conditions were set at 22/20 °C temperature (day/night), 16 h photoperiod, and 85 ± 5 μmol m−2 s−1 photosynthetic photon flux density. Illumination was provided by fluorescent (FL, T0) lamps or four LEDs (T1, T2, T3, and T4) emitting varying wide spectra. Watermelon seedlings had greater shoot length, stem diameter, cotyledon area, shoot dry weight-to-length (DW/L) ratio, and Dickson’s quality index (DQI) under T1 and T3, while leaf area and shoot dry weight (DW) had higher values under T1. Interspecific squash seedlings had greater stem diameter, and shoot and root DW under T1 and T3, while leaf and cotyledon areas were favored under T1. In both species, T0 showed inferior development. It could be concluded that a light source with high red emission, relatively low blue emission, and a red:far-red ratio of about 3 units seems ideal for the production of high-quality watermelon (scion) and interspecific squash (rootstock) seedlings.


Author(s):  
Chaohua Jiang ◽  
Xiaohong Zeng ◽  
Renfeng Shan ◽  
Wu Wen ◽  
Jianfeng Li ◽  
...  

Circular RNAs (circRNAs) are covalently closed circular structures without 5′ caps and 3′ tails, which are mainly formed from precursor mRNAs (pre-mRNAs) via back-splicing of exons. With the development of RNA sequencing and bioinformatic analysis, circRNAs were recently rediscovered and found to be widely expressed in the tree of life. Cerebellar degeneration-related protein 1 antisense RNA (CDR1as) is recognized as one of the most well-identified circRNAs. It contains over 70 miR-7 binding sites and can regulate gene activity by sponging miR-7. Increasing numbers of studies have recently demonstrated that CDR1as is abnormally expressed in many types of tumors, such as colorectal cancer, cholangiocarcinoma and osteosarcoma, and plays a vital role in the development of cancer. However, there are few reviews focusing on CDR1as and cancer. Hence, it is important to review and discuss the role of CDR1as in cancer. Here, we first review the main biological features of CDR1as. We then focus on the expression and roles of CDR1as in cancer. Finally, we summarize what is known on the role of CDR1as in cancer and discuss future prospects in this area of research.


Nanophotonics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1513-1531 ◽  
Author(s):  
Isabelle M. Palstra ◽  
Hugo M. Doeleman ◽  
A. Femius Koenderink

AbstractHybrid cavity-antenna systems have been proposed to combine the sub-wavelength light confinement of plasmonic antennas with microcavity quality factors Q. Here, we examine what confinement and Q can be reached in these hybrid systems, and we address their merits for various applications in classical and quantum optics. Specifically, we investigate their applicability for quantum-optical applications at noncryogenic temperatures. To this end we first derive design rules for hybrid resonances from a simple analytical model. These rules are benchmarked against full-wave simulations of hybrids composed of state-of-the-art nanobeam cavities and plasmonic-dimer gap antennas. We find that hybrids can outperform the plasmonic and cavity constituents in terms of Purcell factor, and additionally offer freedom to reach any Q at a similar Purcell factor. We discuss how these metrics are highly advantageous for a high Purcell factor, yet weak-coupling applications, such as bright sources of indistinguishable single photons. The challenges for room-temperature strong coupling, however, are far more daunting: the extremely high dephasing of emitters implies that little benefit can be achieved from trading confinement against a higher Q, as done in hybrids. An attractive alternative could be strong coupling at liquid nitrogen temperature, where emitter dephasing is lower and this trade-off can alleviate the stringent fabrication demands required for antenna strong coupling. For few-emitter strong-coupling, high-speed and low-power coherent or incoherent light sources, particle sensing and vibrational spectroscopy, hybrids provide the unique benefit of very high local optical density of states, tight plasmonic confinement, yet microcavity Q.


Sign in / Sign up

Export Citation Format

Share Document