Optical networks are evolving toward ultrawide bandwidth and autonomous operation. In this scenario, it is crucial to accurately model and control optical power evolutions (OPEs) through optical amplifiers (OAs), as they directly affect the signal-to-noise ratio and fiber nonlinearities. However, a fundamental contradiction arises between the complex physical phenomena in optical transmission and the required precision in network control. Traditional theoretical methods underperform due to ideal assumptions, while data-driven approaches entail exorbitant costs associated with acquiring massive amounts of data to achieve the desired level of accuracy. In this work, we propose a Bayesian inference framework (BIF) to construct the digital twin of OAs and control OPE in a data-efficient manner. Only the informative data are collected to balance the exploration and exploitation of the data space, thus enabling efficient autonomous-driving optical networks (ADONs). Simulations and experiments demonstrate that the BIF can reduce the data size for modeling erbium-doped fiber amplifiers by 80% and Raman amplifiers by 60%. Within 30 iterations, the optimal controlling performance can be achieved to realize target signal/gain profiles in links with different types of OAs. The results show that the BIF paves the way to accurately model and control OPE for future ADONs.

The idea of a slot waveguide amplifier based on erbium-doped tellurite glass is first theoretically discussed in this work. Choosing the horizontal slot for low propagation loss, the TM mode profile compressed in the insertion layer was simulated, and the gain characteristics of the slot waveguide amplifier were calculated. Combining the capacity to confine light locally and the merits of tellurite glass as an emission host, this optimized amplifier shows enhanced interactions between the electric field and erbium ions and achieves a net gain of 15.21 dB for the 0.01 mW input light at 1530 nm, implying great promise of a high-performance device.

Using the few-mode erbium-doped fiber (FM-EDF) with a simple two-layer erbium-doped structure, we demonstrate an all-fiber FM-EDF amplifier. The gain equalization among the six spatial modes supported by the FM-EDF is achieved when only the pump in the fundamental mode (LP₀₁) is applied. When the signals in six spatial modes are simultaneously amplified, the average modal gain is about 15 dB, and differential modal gain is about 2.5 dB for the signal at 1550 nm.

The influence of the fourth-order dispersion coefficient on the behavior of parametric gain and saturation power of a one-pump fiber optical parametric amplifier over a signal wavelength span in the presence of fiber random dispersion fluctuations was investigated. The output signal power for the parametric gain calculation was obtained by numerically solving the three-coupled amplitude equations. Based on the calculations of the parametric gain over a variation of the signal wavelength, it is found that the saturation power behavior is dependent on the behavior of parametric gain. The manipulations of signal wavelength and the fourth-order dispersion coefficient changed the phase-matching condition, thereby affecting the resulting parametric gain and saturation power.

We demonstrate here an environmentally stable and extremely compactable Er-doped fiber laser system capable of delivering sub-100-fs temporal duration and tens of nanojoules at a repetition rate of 10 MHz. This laser source employs a semiconductor saturable absorber mirror mode-locked soliton laser to generate seed pulses. A single-mode-fiber amplifier and a double-cladding-fiber amplifier (both with double-pass configuration) are bridged by a divider and used to manage the dispersion map and boost the soliton pulses. By using 64 replicas, pulses with as high as 60 nJ energy within 95 fs duration are obtained at 10 MHz, corresponding to 600 kW peak power.

To overcome the beam squint in wide instantaneous frequency, we review a number of system-level optical controlled phase array antennas for beam forming. The optical delay network based on a fiber device in terms of topological structure of an N-bit optical switch, fiber grating, high-dispersion fiber, and vector-sum technology is discussed, respectively. Lastly, an integrated circuit is simply summarized.

We study light propagation through cyclic arrays, composed by copies of a given PT-symmetric dimer, using a group theoretical approach and finite element modeling. The theoretical mode-coupling analysis suggests the use of these devices as output port replicators where the dynamics is controlled by the impinging light field. This is confirmed in good agreement with finite element propagation in an experimentally feasible necklace of passive PT-symmetric dimers constructed from lossy and lossless waveguides.