All-fiber IPDA lidar for CH leakage monitoring using InGaAs/InP single-photon detector.

An integrated path differential absorption (IPDA) lidar for CH leakage monitoring is proposed and demonstrated. In the simplified all-fiber optical layout, a homemade InGaAs/InP single-photon detector (SPD) using multi-channel technique with multi-mode fiber coupling is used to increase the maximum count rate and coupling efficiency. The system is calibrated in intensity and frequency domains.

Three-dimensional detection of CO and wind using a 1.57 µm coherent differential absorption lidar.

A 1.57-µm coherent differential absorption lidar is demonstrated for measuring three-dimensional CO and wind fields simultaneously. The maximum detection range of CO is up to 6 km with a range resolution of 120 m and a time resolution of 1 min.

Deep neural network for modeling soliton dynamics in the mode-locked laser.

Integrating the information of the first cycle of an optical pulse in a cavity into the input of a neural network, a bidirectional long short-term memory (Bi_LSTM) recurrent neural network (RNN) with an attention mechanism is proposed to predict the dynamics of a soliton from the detuning steady state to the stable mode-locked state. The training and testing are based on two typical nonlinear dynamics: the conventional soliton evolution from various saturation energies and soliton molecule evolution under different group velocity dispersion coefficients of optical fibers. In both cases, the root mean square error (RMSE) for 80% of the test samples is below 15%.

Generation and dynamics of soliton and soliton molecules from a VSe/GO-based fiber laser.

Recently, in addition to exploring the application of new saturable absorber devices in fiber lasers, soliton dynamics has also become a focus of current research. In this article, we report an ultrashort pulse fiber laser based on VSe/GO nanocomposite and verify the formation process of soliton and soliton molecules by the numerical simulation. The prepared VSe/GO-based device shows excellent saturable absorption characteristics with a modulation depth of 14.