Using a global optimization algorithm, we show that significant gain in performance can be obtained by using the Ungerboeck's set-partitioning scheme for DP-QPSK and DP-16QAM in four dimensions.

Global optimization of fiber-optic communication systems using four-dimensional modulation formats

A photonic crystal fiber (PCF) for sensing of sulfuric acid is designed and analyzed using Comsol Multiphysics. To analyze the sensor performance, 0%, 10%, 20%, 30%, 40% H2SO4 solution is placed into the fiber separately and then relative sensitivity, confinement loss, birefringence, effective area etc. are investigated for each solution over wavelength ranging from 0.8 to 1.8 µm. The sensor structure affords moderately high relative sensitivity and around 63.4% sensitivity is achieved for the highest concentration of H2SO4 at the wavelength 1.5 µm in x polarization direction. This PCF model also shows zero confinement loss for all solutions of H2SO4 over wavelength ranging from 1 to 1.35 µm and later on approximately 1.422 × 10−17 dB/km confinement loss is found for the highest concentration of H2SO4 at 1.5 µm wavelength. Besides, higher birefringence is attained when the concentration of sulfuric acid is lower and it is achieved 7.5 × 10−4 at 1.5 µm wavelength. Moreover, higher sensing area is achieved at high concentration of sulfuric acid.

Chemical sensing through photonic crystal fiber: sulfuric acid detection

Adaptive neuro-fuzzy estimation of optimal lens system parameters

We present a closed-form maximum likelihood-based data detection algorithm for long-haul optical channels with dominant nonlinear phase noise induced by self-phase modulation. The closed-form detector is evaluated in terms of symbol error rate as a function of input power, and compared with other sub-optimal detectors as well as a non-parametric detector. We show that the performance of the detector deteriorates for high input power levels yielding an optimal operation region. We also provide insights into the behavior of the detector in the highly nonlinear regime.

https://publications.lib.chalmers.se/records/fulltext/local_139199.pdf

An ML-Based Detector for Optical Communication in the Presence of Nonlinear Phase Noise

We report a novel digital coherent receiver based on sampling the signal in the optical domain to overcome the speed limitations of electrical analog-to-digital converters. Digital coherent receivers with aggregate optical sampling rates of up to 112 GHz are realized experimentally. The performance of such receivers is investigated in transmission experiments. Transmission of 56 GBd quadrature phase-shift keying signals over 610-km standard single-mode fiber and coherent detection with electronic impairment mitigation is demonstrated. The employed electrical analog-to-digital converters have only 20 GHz bandwidth and a sampling rate of 50 GHz.

/pdf/high-speed-digital-coherent-receiver-based-on-parallel-2r07oo6bob.pdf

High-Speed Digital Coherent Receiver Based on Parallel Optical Sampling

We present a global optimization algorithm especially appropriate for the optimization of optical communication systems. It is independent of external parameters and converges to the global optimum, considerably reducing the simulation time. The algorithm is used to optimize the fiber launch powers and dispersion map of a single-channel OOK, DPSK and DQPSK at several data rates.

An Algorithm for Global Optimization of Optical Communication Systems

A method for processing data in an optical network element is provided, wherein a multicarrier signal is linear pre-coded, and wherein the linear pre-coded signal is modulated An according optical network element is also suggested

Method for processing data in an optical network element and optical network element

We present a novel, fast method for optimizing the performance of a system. It is used to optimize the dispersion map and signal power in a DQPSK 111Gb/s link.

Global optimization of optical communication systems

We use a global optimization algorithm to find the optimum fiber launch powers and dispersion map of single-channel RZ-DPSK and RZ-DQPSK systems at data rates ranging from 5 Gbit/s to 130 Gbit/s.

Global optimization of RZ-DPSK and RZ-DQPSK systems at various data rates

Different pulse shapes are presented as alternative to traditional (N)RZ pulses in communication systems using direct detection. The pulses are efficiently generated in the frequency domain using the discrete Fourier transform. The trade-off between spectral occupancy and eye opening is discussed and performance is evaluated by means of simulations.

Oscar Gaete

Papers

An Algorithm for Global Optimization of Optical Communication Systems

Method for processing data in an optical network element and optical network element

Global optimization of optical communication systems

Global optimization of RZ-DPSK and RZ-DQPSK systems at various data rates

Pulse shaping using the discrete fourier transform for direct detection optical systems