Quenching properties of gas mixture in a resistive plate chamber operated with streamer mode were investigated using optical image taken by the CCD camera and signal pulse waveform recorded by the digital oscilloscope. We have tested four quenching gases: C2H2F4, C2F6, CBrF3 and SF6. Streamer size, brightness and induced charge linearly depend on the ratio of Ar to quenching gas and their slope...

We demonstrate an efficient fiber-coupled source of nondegenerate polarization-entangled photons at 795 and 1609 nm using bidirectionally pumped parametric down-conversion in bulk periodically poled lithium niobate. The single-mode source has an inferred bandwidth of 50GHz and a spectral brightness of 300 pairs/s/GHz/mW of pump power that is suitable for narrowband applications such as entangle...

Extensive studies have been performed on random lasers in which multiple-scattering feedback is used to generate coherent emission. Q-switching and mode-locking are well-known routes for achieving high peak power output in conventional lasers. However, in random lasers, the ubiquitous random cavities that are formed by multiple scattering inhibit energy storage, making Q-switching impossible. I...

In this paper we present a non-interactive algorithm to estimate a representative value for the sky background on CCD images. The method we have devised uses the mode as a robust estimator of the background brightness in sub-windows distributed across the input frame. The presence of contaminating objects is detected through the study of the local intensity distribution function and the perturb...

We describe an achromatic, phase-stable, broadband source of polarization-entangled photon pairs with high spectral brightness that uses four-wave mixing in a fiber Sagnac interferometer. We achieved a polarizationentangled two-photon coincidence rate of 7 kHz per 0.5 THz 0.9 nm of bandwidth per 300 W of average pump power. At this rate, we observed two-photon fringe interference visibilities g...

This work focuses on determining the latitudinal structure of ammonia vapor in Saturn’s cloud layer near 1.5 bars using the brightness temperature maps derived from the Cassini RADAR (Elachi et al. [2004], Space Sci. Rev. 115, 71–110) instrument, which works in a passive mode to measure thermal emission from Saturn at 2.2-cm wavelength. We perform an analysis of five brightness temperature maps...

We demonstrate a wavelength-tunable, fiber-coupled source of polarization- entangled photons with extremely high spectral brightness and quality of entanglement. Using a 25 mm PPKTP crystal inside a polarization Sagnac interferometer we detect a spectral brightness of 273000 pairs (s mW nm)(-1), a factor of 28 better than comparable previous sources while state tomography showed the two-photon ...

Synchrotrons and storage rings deliver radiation across the electromagnetic spectrum at high repetition rates, and free electron lasers produce radiation pulses with high peak brightness. However, at present few light sources can generate both high repetition rates and high brightness outside the optical range. We propose to create steady-state microbunching (SSMB) in a storage ring to produce ...