Optically preamplified receiver with low quantum limit

An optically preamplified receiver configuration resulting in a very low quantum limit is presented. Optical amplifiers are proven to efficiently enhance the receiver sensitivity of optical communication systems. We present an optically preamplified OOK/DD receiver scheme with a very low quantum limit, which is predicted to outperform previously studied configuration

Photonic techniques for sub-Terahertz wireless data transmission

\u3cp\u3eWireless data communication links with capacities beyond 100 Gbit/s will require operating at sub-Terahertz frequencies using a large bandpass bandwidth facing new engineering challenges. We review several implementation aspects by using photonic technologies.\u3c/p\u3

On analytical expressions for the distribution of the filtered output of square envelope receivers with signal and colored Gaussian noise input

Closed-form expressions for the moment generating function (MGF) of the filtered output of square envelope receivers with signal and colored Gaussian noise input are derived. The informative signal is a binary sequence of rectangular pulses. The considered Gaussian processes are the Wiener process, a Gaussian process with linear covariance (moving average) and the Ornstein-Uhlenbeck process. The derived MGFs are then applied to the problem of finding the quantum limit for optically preamplified, direct detection receivers

Single photodiode, single wavelength, and single polarization 65 Gb/s 16-QAM and QPSK coherent transmission

\u3cp\u3eThis paper presents an investigation of an optical transmission scheme using a single photodetector (PD) which, as in conventional coherent detection systems, allows the linear transfer of the amplitude and phase information of the optical field into the electrical domain. This is possible by means of optical heterodyne detection and the adjustment of the carrier-to-signal power ratio (CSPR), thus the undesired signal-to-signal beating products (SSBP) due to the PD square-law, can be considered negligible. Through simulation, the CSPR impact on this scheme is determined. Then, its experimental validation is done for a single wavelength and single polarization transmission with a total bitrate of 65 Gb/s over 10 km of standard single-mode fiber (SSMF).\u3c/p\u3

On a recursive formula for the moments of phase noise

We present a recursive formula for the moments of phase noise in communication systems. The phase noise is modeled using continuous Brownian motion. The recursion is simple and valid for an arbitrary initial phase value. The moments obtained bp the recursion are used to calculate approximations to the probability density function of the phase noise, using orthogonal polynomial series expansions and a maximum entropy criterio

Silicon nitride integrated optical beamforming network for millimeter wave photonics systems

\u3cp\u3eThis work presents the design of a mathbf{1x4} optical true time delay beamforming network integrated into a Si\u3csub\u3e3\u3c/sub\u3eN\u3csub\u3e4\u3c/sub\u3ephotonic chip for hybrid millimeter wave/photonic systems. The spectral periodicity of a ring resonator-based tree structure is exploited to provide simultaneously the same delay configuration to different gigabit optical channels, increasing the effective beamforming bandwidth. The free spectral range is fixed to 33.3 GHz to assure the combability with wavelength division multiplexing applications. The simulation results show that the progressive delay between outputs can be continuously tuned from 0 ps to 20 ps. These values assure the operation at 60 GHz band.\u3c/p\u3

Error probability evaluation of optical systems disturbed by phase noise and additive noise

A direct and efficient method for evaluation of the error probability of optical heterodyne receivers in the presence of phase noise is presented. Closed form expressions for the statistics of the decision variable, including photodetector shot noise and thermal noise from electronic circuitry, are shown. Amplitude shift keying (ASK), frequency shift keying (FSK) and differential phase-shift keying (DPSK) are examined

24-dimensional modulation formats for 100 Gbit/s IM-DD transmission systems using 850 nm single-mode VCSEL

\u3cp\u3eTwenty-four dimensional modulation format with 2 bit/symbol spectrum efficiency is proposed and investigated in an up to 100 Gbit/s VCSEL-based IM-DD transmission system with respect to the channel bandwidth and the power budget.\u3c/p\u3