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Nonlinearity in coherent fiber links is fundamentally driven by the temporal statistics and spectral structure of signal intensity. This paper develops a unified framework that links block-level energy statistics of shaped constellations to…

Signal Processing · Electrical Eng. & Systems 2026-03-06 Ravneel Prasad , Emanuele Viterbo

The interaction of light with objects and media moving at relativistic and superluminal speeds enables unconventional phenomena such as Fresnel drag, Hawking radiation, and light amplification. Synthetic motion, facilitated by modulated…

Deep space explorations require transferring huge amounts of data quickly from very distant targets. Laser communication is a promising technology that can offer a data rate of magnitude faster than conventional microwave communication due…

We present a simple and robust approach to reduce laser speckle, which has limited the adoption of lasers in imaging and display applications. We use colloidal solutions that can quickly reduce speckle contrast due to the Brownian motion of…

Optics · Physics 2017-03-30 Brandon Redding , Graham Allen , Eric R. Dufresne , Hui Cao

Atmospheric turbulences can generate scintillation or beam wandering phenomena that impairs free space optical (FSO) communication. In this paper, we propose and demonstrate a proof-of-concept FSO communication receiver based on a spatial…

In practical satellite-based quantum key distribution (QKD) systems, the preparation and transmission of polarization-encoding photons suffer from complex environmental effects and high channel-loss. Consequently, the hinge to enhancing the…

Quantum Physics · Physics 2024-11-14 Zexu Wang , Huaxing Xu , Ju Li , Jinquan Huang , Hui Han , Changlei Wang , Ping Zhang , Feifei Yin , Kun Xu , Bo Liu , Yitang Dai

We design and experimentally demonstrate a radio frequency interference management system with free-space optical communication and photonic signal processing. The system provides real-time interference cancellation in 6 GHz wide bandwidth.

Signal Processing · Electrical Eng. & Systems 2021-07-30 Yang Qi , Ben Wu

We present a novel laser mode-locking scheme and discuss its unusual properties and feasibility using a theoretical model. A large set of single-frequency continuous-wave lasers oscillate by amplification in spatially separated gain media.…

Applications relying on mid-infrared radiation (Mid-IR, $\lambda\sim$ 3-30 $\mu$m) have progressed at a very rapid pace in recent years, stimulated by scientific and technological breakthroughs. Mid-IR cameras have propelled the field of…

Typical astronomical spectrographs have a resolution ranging between a few hundred to 200.000. Deconvolution and correlation techniques are being employed with a significance down to 1/1000 th of a pixel. HeAr and ThAr lamps are usually…

Astrophysics · Physics 2015-05-13 Piet O. Schmidt , Stefan Kimeswenger , Hans Ulrich Kaeufl

Inspired by the concept of coherent frozen waves, this paper introduces one possible theoretical framework of its partially coherent version, a frozen spatial coherence, in which a desired two-point correlation structure of an optical field…

Optics · Physics 2022-06-22 M. A. Pinto , P. A. Brandão

High peak power ultrafast lasers are widely used in nonlinear spectroscopy but often limit its spectral resolution because of the broad frequency bandwidth of ultrashort laser pulses. Improving the resolution by achieving spectrally narrow…

Optics · Physics 2009-11-13 Stanislav O. Konorov , Xiaoji G. Xu , John W. Hepburn , Valery Milner

Pixel size in cameras and other refractive imaging devices is typically limited by the free-space diffraction. However, a vast majority of semiconductor-based detectors are based on materials with substantially high refractive index. We…

Optics · Physics 2018-03-28 Bo Fan , Sandeep Inampudi , Viktor A. Podolskiy

Previous and ongoing searches for extraterrestrial optical and infrared nanosecond laser pulses and narrow line-width continuous emissions have so far returned null results. At the commonly used observation cadence of $\sim 10^{-9}\,$s,…

Instrumentation and Methods for Astrophysics · Physics 2018-12-12 Michael Hippke

We propose a new scintillation-type detector in which high-energy radiation produces electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The…

Instrumentation and Detectors · Physics 2009-11-13 A. Kastalsky , S. Luryi , B. Spivak

Consider a ultraviolet (UV) scattering communication system where the position of the transmitter is fixed and the receiver can move around on the ground. To obtain the link gain effectively and economically, we propose an algorithm based…

Signal Processing · Electrical Eng. & Systems 2019-04-09 Difan Zou , Zhengyuan Xu , Chen Gong

In optical communications, logical bits are encoded in physical degrees-of-freedom (DoFs) of the electromagnetic field. Consequently, optical scattering in a communications channel compromises the information transfer. In the…

Power spectral density measurements of any sampled signal are typically restricted by both acquisition rate and frequency response limitations of instruments, which can be particularly prohibitive for video-based measurements. We have…

Biological Physics · Physics 2009-02-10 Wesley Philip Wong , Ken Halvorsen

Optical modulators can be made nowadays with high modulation speed, broad bandwidth, while being compact, owing to the recent advance in material science and microfabrication technology. However, these optical modulators usually work for…

The radiation pattern of transmit antennas varies and fluctuates as receivers change their location, other objects move around, and due to the antenna design itself. In this paper, we demonstrate how this observation can be exploited to…

Information Theory · Computer Science 2020-05-18 Milad Johnny , Alireza Vahid