arXiv subjects

Wojciech Zwoliński

Publications and source records attributed to Wojciech Zwoliński.

4 recordsLinked to original sources

arXiv2026

Non-invasive super-resolution imaging through scattering media using highly nonlinear labels

While scattered light conveys most of the information we perceive, scattering may also distort that information before it reaches our detectors. The problem is acute in many applications, such as in high-resolution microscopy of biological tissue, where scattering degrades both resolution and signal-to-noise ratio. Here, for the first time, we demonstrate that combining two intrinsic properties of scattered light: speckle statistics and the memory effect, with highly non-linear optical response yields, rather surprisingly, super-resolution, low-background, non-invasive imaging of objects completely hidden behind a strongly scattering, opaque layers. Crucially, our technique of Nonlinear Imaging with Speckle Excitation (NISE) does not resort to wavefront shaping, adaptive optics, complicated optical setups, or iterative image reconstruction algorithms. Because the strategy relies solely on the properties of scattered light and high-order nonlinear response of the luminescent labels, it can be applied to any speckle-forming propagation, from biological tissue to multicore fibers, combined with any type of phenomenon that exhibits a sufficiently high order nonlinearity.

physics.optics↗

arXiv2019

Photon Efficiency Limits in the Presence of Background Noise

We identify theoretical limits on the photon information efficiency (PIE) of a deep-space optical communication link constrained by the average signal power and operated in the presence of background noise. The ability to implement a scalable modulation format, Geiger-type direct photon counting detection, and complete decoding of detection events are assumed in the analysis. The maximum attainable PIE is effectively determined by the background noise strength and it exhibits a weak, logarithmic dependence on the detected number of background photons per temporal slot.

quant-ph↗

arXiv2018

Range Dependence of an Optical Pulse Position Modulation Link in the Presence of Background Noise

We analyze the information efficiency of a deep-space optical communication link with background noise employing the pulse position modulation (PPM) format and a direct-detection receiver based on Geiger-mode photon counting. The efficiency, quantified using Shannon mutual information, is optimized with respect to the PPM order under the constraint of a given average signal power in simple and complete decoding scenarios. We show that the use of complete decoding, which retrieves information from all combinations of detector photocounts occurring within one PPM frame, allows one to achieve information efficiency scaling as the inverse of the square of the distance, i.e. proportional to the received signal power. This represents a qualitative enhancement compared to simple decoding, which treats multiple photocounts within a single PPM frame as erasures and leads to inverse-quartic scaling with the distance. We provide easily computable formulas for the link performance in the limit of diminishing signal power.

quant-ph↗

arXiv2018

Optimizing deep-space optical communication under power constraints

We investigate theoretically the efficiency of deep-space optical communication in the presence of background noise. With decreasing average signal power spectral density, a scaling gap opens up between optimized simple-decoded pulse position modulation and generalized on-off keying with direct detection. The scaling of the latter follows the quantum mechanical capacity of an optical channel with additive Gaussian noise. Efficient communication is found to require a highly imbalanced distribution of instantaneous signal power. This condition can be alleviated through the use of structured receivers which exploit optical interference over multiple time bins to concentrate the signal power before the detection stage.

quant-ph↗