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The existing methods for measuring the orbital-angular-momentum (OAM) spectrum suffer from issues such as poor efficiency, strict interferometric stability requirements, and too much loss. Furthermore, most techniques inevitably discard part of the field and measure only a post-selected portion of the true spectrum. Here, we propose and demonstrate an interferometric technique for measuring the true OAM spectrum of optical fields in a single-shot manner. Our technique directly encodes the OAM-spectrum information in the azimuthal intensity profile of the output interferogram. In the absence of noise, the spectrum can be fully decoded using a single acquisition of the output interferogram, and, in the presence of noise, acquisition of two suitable interferograms is sufficient for the purpose. As an important application of our technique, we demonstrate measurements of the angular Schmidt spectrum of the entangled photons produced by parametric down-conversion and report a broad spectrum with the angular Schmidt number 82.1.

Solid-state microwave systems offer strong interactions for fast quantum logic and sensing but photons at telecom wavelength are the ideal choice for high-density low-loss quantum interconnects. A general-purpose interface that can make use of single photon effects requires < 1 input noise quanta, which has remained elusive due to either low efficiency or pump induced heating. Here we demonstrate coherent electro-optic modulation on nanosecond-timescales with only $$0.1{6}_{-0.01}^{+0.02}$$ 0.1 6 − 0.01 + 0.02 microwave input noise photons with a total bidirectional transduction efficiency of 8.7% (or up to 15% with $$0.4{1}_{-0.02}^{+0.02}$$ 0.4 1 − 0.02 + 0.02 ), as required for near-term heralded quantum network protocols. The use of short and high-power optical pump pulses also enables near-unity cooperativity of the electro-optic interaction leading to an internal pure conversion efficiency of up to 99.5%. Together with the low mode occupancy this provides evidence for electro-optic laser cooling and vacuum amplification as predicted a decade ago.

The present study on evaluation of antioxidant activity of the flowers and seed oil of Neem plant Azardirachta indica A. Juss revealed that the ethanolic extract of flowers and seed oil at 200 μg/ml producing the highest free radical scavenging activity i.e. 64.17±0.02% and 66.34±0.06% respectively. The Neem oil has the highest amount of total phenol content (132 μg/ml) which is responsible for highest percentage of inhibition of DPPH radical. In conclusion Neem flower and seed oil have potential for use in human health which is used as food by common people and in diabetes and Neem seed oil is widely used for variety of diseases and also antioxidant potential for use in different pharmaceutical industries.

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