Real-time automatic polarization control based on golden section search and proportional endless reset-free control action.

We propose and experimentally demonstrate a real-time automatic polarization control scheme for fiber-optic systems based on golden section search (GSS) and proportional endless reset-free (PE-RF) control action. In the proposed method, we separate the orthogonal components of the incoming state of polarization of light and use one of the polarization components to generate a feedback signal such that the power in the other component is maximized. The feedback signal is applied to waveplates of an electronic polarization controller for which the required voltage signals are derived by the application of GSS and PE-RF control algorithms, implemented on an Arduino Uno R3 microcontroller.

Fiber-optic frequency comb generation using low-seed power FWM and Brillouin-assisted power equalization.

In this paper, we experimentally demonstrate an all-fiber broadband tunable optical frequency comb (OFC) operating in the C-band. The OFC is generated by broadening a power-equalized stimulated Brillouin scattering (SBS)-based seed comb (SBS-OFC) using four-wave mixing (FWM) in a highly nonlinear fiber (HNLF). The seed SBS-OFC is obtained from a pump and Stokes power recycling cavity, which yields ≈15 comb lines with 10.

All-SBS fiber-based setup for optical frequency comb generation utilizing a pump recycling technique and comb line isolation by implementing Brillouin amplification.

We describe an all-stimulated Brillouin scattering (SBS) fiber-based setup for the generation, amplification, and isolation of frequency components from an optical frequency comb (OFC). The cascaded SBS-OFC is obtained by utilizing pump and Stokes power recycling techniques. A total of >15 comb lines within a 45 dB bandwidth, having an average power of 16 dBm, is observed in the 1550 nm wavelength region of operation.

Reduced sampling rate Kalman filters for carrier phase and frequency offset tracking in 200 Gbps 16 QAM coherent communication system.

We propose 1 state and 2 state multi-step Kalman filters (MKFs) to estimate and compensate CFO, LPN and NLPN in long-haul coherent fiber-optic communication systems. The proposed filters generate state estimates once every m symbols and therefore operate at a reduced sampling rate compared to conventional KFs that perform symbol by symbol processing. No computations are performed to obtain phase estimates of the intermediate [Formula: see text] samples; instead, the present and previous estimates are averaged and used to derotate the intermediate [Formula: see text] samples which are then demodulated to recover the transmitted symbols.

16 Gbps random bit generation using chaos in near-symmetric erbium-doped fiber ring laser.

We demonstrate a bias-free random bit generator at 16 Gbps using chaos in a near-symmetric erbium-doped fiber (EDF) ring laser. The laser consists of two EDFs, each pumped at 980 nm, two intracavity filters of central wavelength 1549.30 nm, and two 90:10 output couplers.

Experimental demonstration of 12.5 GHz wideband chaos in symmetric dual-port EDFRL.

We study the dynamics of chaos in a dual-port erbium-doped fiber ring laser (EDFRL). The laser consists of two erbium-doped fibers, intracavity filters at 1549.32 nm, isolators, and couplers.