Tootfinder

Optimizing brightness of SPDC source in Laguerre-Gaussian modes using type-0 periodically-poled nonlinear crystal
Jungmo Lee, Kyungdeuk Park, Dongkyu Kim, Yonggi Jo, Dong-Gil Im, Yong Sup Ihn
https://arxiv.org/abs/2506.10385

Optimizing brightness of SPDC source in Laguerre-Gaussian modes using type-0 periodically-poled nonlinear crystal
Photon pairs generated via spontaneous parametric down-conversion (SPDC) can exhibit entanglement in the Laguerre-Gaussian (LG) mode basis, which enables high-dimensional free-space quantum communication by exploiting the high-dimensional space spanned by the LG modes. For such free-space quantum communication, the brightness of the quantum light source plays an important role due to the atmospheric turbulence and photon loss. A variety of studies have analyzed the SPDC brightness by decomposin…

we need to return,,,

Dat ik na al die jaren nog een Midsummer Murders zie die ik nog nooit gezien heb volgens mij.
(King's crystal)

I've been using #kicad to reverse my dad's frequency standard, locked off BBC Radio4 198kHz. I'm sure there are bits I've not got right, but the vague shape is there - a loop with input amp/filters from the receiver, which ends up combining with the divided output (at 2kHz) with the output of a 10MHz crystal oscillator based on a 74HC00; that combined result ends up driving a var…

A tunable, continuous-wave 130-mW laser at 213 nm
Lukas M\"oller, Stephan Hannig, Stefan Truppe, Simon Stellmer
https://arxiv.org/abs/2506.08709 https…

A tunable, continuous-wave 130-mW laser at 213 nm
We present a tunable, continuous-wave (CW) laser system emitting at 213 nm, based on the frequency quadrupling of a single Ti:sapph laser. The setup features two sequential, cavity-enhanced second-harmonic generation (SHG) stages. The first stage uses an LBO crystal and achieves a conversion efficiency of over 80%, yielding up to 3.3 W at 426 nm. The second stage employs a Brewster-cut BBO crystal with an elliptical beam waist to mitigate UV-induced degradation, producing up to 130 mW of deep U…

Emergent anisotropic three-phase order in critically doped superconducting diamond films
Jyotirmay Dwivedi, Jake Morris, Saurav Islam, Kalana D. Halanayake, Gabriel A. Vazquez-Lizardi, David Snyder, Anthony Richardella, Luke Lyle, Danielle Reifsnyder Hickey, Nazar Delegan, F. Joseph Heremans, David D. Awschalom, Nitin Samarth
https://

Emergent anisotropic three-phase order in critically doped superconducting diamond films
Two decades since its discovery, superconducting heavily boron-doped diamond (HBDD) still presents unresolved fundamental questions whose resolution is relevant to the development of this material for quantum technologies. We use electrical magnetotransport measurements of critically-doped homoepitaxial single crystal HBDD films to reveal signatures of intrinsic (electronic) granular superconductivity. By studying the dependence of electrical resistivity on temperature and magnetic field vector…

Generation of frequency entanglement by rotating Doppler effect
Bolong Yi, Ling Chen, Baocheng Zhang
https://arxiv.org/abs/2506.09488 https://

Generation of frequency entanglement by rotating Doppler effect
We propose a method to generate the frequency entanglement, allowing a continuous generation of entangled two-photon states in a hybrid degree of freedom by post-manipulation. Our method is based on type-II spontaneous parametric down-conversion in a nonlinear crystal and the rotation Doppler effect by rotating the q-plates, without preset discrete frequency entanglement. This allows the arbitrary modification of frequency entangled photons in a wide frequency range at room temperature, offerin…

🇺🇦 Auf radioeins läuft...
Keane:
🎵 Crystal Ball
#NowPlaying #Keane
https://goodknightproductions1.bandcamp.com/track/crystal-ball
https://open.spotify.com/track/3e90d7sOsXNnVyBfOhjo0z