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We present a concept to improve the spatial resolution of silicon pixel-detectors via the implementation of a sub-pixel cross-coupling, which introduces directional charge sharing between pixels. The charge-collection electrode is segmented…

Instrumentation and Detectors · Physics 2020-07-24 Sinuo Zhang , David-Leon Pohl , Tomasz Hemperek , Jochen Dingfelder

We investigate dispersion and absorption properties of a weak probe field in a four level atomic system through interacting dark resonances. We show that two narrow peaks appears in the optical spectra due to the presence of interacting…

Quantum Physics · Physics 2010-01-12 Kh. Saaidi , S. Dehnar Sydid , S. W. Rabiei

New feasibity of coherent quantum control of four-wave mixing processes in a resonant Doppler-broadened medium are studied. We propose a technique which enables one to enhance the quantum efficiency of nonlinear optical conversion. At the…

Spectroscopic features revealing the coherent interaction of a degenerate two-level atomic system with two optical fields are examined. A model for the numerical calculation of the response of a degenerate two-level system to the action of…

Quantum Physics · Physics 2007-05-23 A. Lezama S. Barreiro A. Lipsich A. M. Akulshin

We show how quantum coherence effects can be used to improve the resolution and the contrast of diffraction-limited images imprinted onto a probe field. The narrow and sharp spectral features generated by double-dark resonances (DDR) are…

Quantum Physics · Physics 2014-03-26 Onkar N. Verma , Tarak N. Dey

We experimentally demonstrate coherent amplification of probe field in a tripod-type atoms driven by strong coupling, signal and weak probe fields. We suppress linear and nonlinear atomic absorptions for resonant and near resonant probe via…

In radar systems, high resolution in the Doppler dimension is important for detecting slow-moving targets as it allows for more distinct separation between these targets and clutter, or stationary objects. However, achieving sufficient…

Computer Vision and Pattern Recognition · Computer Science 2025-05-26 Denisa Qosja , Kilian Barth , Simon Wagner

We investigate the frequency estimation of an optical field suffering from an unavoidable dissipative environment. Generally, dissipative noises greatly reduce the precision. Here, we find that two-photon driving can improve the measurement…

Quantum Physics · Physics 2020-07-01 Dong Xie , Chunling Xu

Super-resolution theory aims to estimate the discrete components lying in a continuous space that constitute a sparse signal with optimal precision. This work investigates the potential of recent super-resolution techniques for spectral…

Information Theory · Computer Science 2016-11-24 M. Ferreira Da Costa , W. Dai

We have demonstrated that near complete coherence can be achieved in a four level double lambda-like systems using a train of ultra-short optical pulses. The effect of the Doppler broadening has been analyzed and a scheme has been proposed…

Optics · Physics 2014-01-16 Pawan Kumar , Amarendra K. Sarma

We demonstrate spectroscopy of incoherent light with sub-diffraction resolution. In a proof-of-principle experiment we analyze the spectrum of a pair of incoherent point-like sources whose separation is below the diffraction limit. The two…

Super-resolution tasks oriented to images captured in ultra-dark environments is a practical yet challenging problem that has received little attention. Due to uneven illumination and low signal-to-noise ratio in dark environments, a…

Computer Vision and Pattern Recognition · Computer Science 2023-09-12 Jiaxin Gao , Ziyu Yue , Yaohua Liu , Sihan Xie , Xin Fan , Risheng Liu

Light field imaging has recently known a regain of interest due to the availability of practical light field capturing systems that offer a wide range of applications in the field of computer vision. However, capturing high-resolution light…

Computer Vision and Pattern Recognition · Computer Science 2018-01-16 Reuben A. Farrugia , Christine Guillemot

Absorption profile of a four-level ladder atomic system interacting with three driving fields is studied perturbatively and analytical results are presented. Numerical results where the driving field strengths are treated upto all orders…

Quantum Physics · Physics 2015-06-26 S N Sandhya

This paper attempts a probe into negative refraction without absorption by means of an incoherent pump field and a strong coherent field coupling the dense four-level atomic system.With the application of the incoherent pump field to…

Quantum Physics · Physics 2024-03-05 Shun-Cai Zhao , Zheng-Dong Liu , Qi-Xuan Wu

We propose and demonstrate pump-probe spectroscopy of rubidium absorption which reveals the sub-Doppler hyperfine structure of the $^{5}$S$_{1/2} \leftrightarrow$ $^{5}$P$_{3/2}$ (D2) transitions. The counter propagating pump and probe…

Coherence phenomena in four-level atomic system, cyclicly driven by three coherent fields, are investigated thoroughly at zero and weak magnetic fields. Each strongly interacting atomic state is converted to a triplet due to a dynamical…

Optics · Physics 2016-09-20 F. Ghafoor , R. G. Nazmitdinov

The propagation of a weak probe field in a laser-driven four-level atomic system is investigated. We choose mercury as our model system, where the probe transition is in the ultraviolet region. A high-resolution peak appears in the optical…

Quantum Physics · Physics 2009-11-13 M. Mahmoudi , M. Sahrai , J. Evers

We extend the measurement range of optical correlation-domain reflectometry (OCDR) by modulating the laser output frequency at two frequencies, while preserving spatial resolution. We demonstrate distributed reflectivity sensing with a…

Instrumentation and Detectors · Physics 2023-09-06 Mana Sakamoto , Tomoya Miyamae , Kohei Noda , Kentaro Nakamura , Heeyoung Lee , Yosuke Mizuno

We introduce the first method to enable an optical amplification of a coherent Raman spectroscopy signal called radio frequency Doppler Raman spectroscopy. Doppler Raman measurements amplify the optical signals in coherent Raman…

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