Experimental Dataset of Nonlinear Dynamics in a Three-Semiconductor-Laser System Coupled Through a 2×2 X-Coupler

Dataset Description This dataset contains experimental time-series measurements and operating parameters obtained from a three-semiconductor-laser system interconnected through a common 2×2 optical fiber X-coupler with local optoelectronic feedback branches. The experimental system consists of three single-mode semiconductor laser diodes operating at a wavelength of 1310 nm. Each laser branch incorporates a variable optical attenuator and a photodetector to control and establish its local optoelectronic feedback loop. The three optical branches are interconnected through a common 2×2 X-coupler, providing optical interaction between the laser branches and a common output signal at Port 4. A locally developed multi-channel current controller (MCC) was used to independently adjust the DC bias current supplied to each laser diode. Dataset Contents The dataset includes eight independent experimental runs, with four recorded signals for each run, resulting in 32 CSV files. The four signals correspond to: Signal 1: Feedback signal associated with Laser Diode 1. Signal 2: Feedback signal associated with Laser Diode 2. Signal 3: Feedback signal associated with Laser Diode 3. Signal 4: Common output signal detected at Port 4 of the X-coupler. The package also includes an Excel workbook (Parameters.xlsx) containing the laser operating currents, threshold currents, maximum optical powers, optical transmission settings, measured output powers, and experimental run information. Data Acquisition Specifications Acquisition instrument: Tektronix MSO 5204 mixed-signal oscilloscope. Oscilloscope bandwidth: 2 GHz. Sampling rate: 1.0 GS/s. Sampling interval: 1 ns. Record length: 100,000 samples per signal. Total recording duration: approximately 100 µs. Signal amplitude: Voltage (V). Time coordinate: microseconds (µs). Data Organization The CSV directory is organized into eight subfolders corresponding to Experimental Runs 1–8. Each folder contains four CSV files representing the three laser feedback signals and the common output signal. The Parameters.xlsx workbook provides two worksheets: Results and Paper_Table_Summary, documenting the operating conditions and experimental parameters. Scientific Applications These experimental measurements can be used for nonlinear time-series analysis, including time-domain characterization, phase-space reconstruction, Fast Fourier Transform (FFT), correlation dimension estimation, largest Lyapunov exponent analysis, and the investigation of complex dynamical behavior in coupled semiconductor lasers.