We experimentally demonstrate a free-space data transmission system in an indoor simulated smoke chamber with a laser carrier of an erbium-doped actively mode-locked fiber laser and a holmium-doped actively mode-locked fiber laser. Two additional semiconductor lasers operating at 0.85 and 1.06 µm are used to calibrate the visibility of a smoke channel using the Ijaz model and compare smoke attenuation with 1.55 and 2.04 µm lasers. The eye patterns and bit error rates of 1.55 and 2.04 µm laser carriers with a data rate of 4.04 Gbps are investigated experimentally at 0.5, 0.05, and 0.005 km visibilities. The experimental results show that the smoke attenuation is wavelength dependent for V < 0.5 km. As the visibility decreases, the long wavelength laser is less affected by the attenuation and power fluctuation caused by Mie scattering. The measured optical signal-to-noise ratios of the 1.55 and 2.04 µm laser carriers for V = 0.005 km are 4.83 and 8.62 dB, respectively. The corresponding link sensitivities are −14.59 and −17.74 dBm, respectively, indicating that the 2.04 µm data transmission system is more reliable under an extremely dense smoke condition.

Free-space optical communication (FSOC) enables high-speed, secure, and scalable data transmission, with great potential for space–ground networks. However, existing FSOC systems predominantly employ point-to-point transmitters, each requiring bulky beam steering devices with complex control mechanisms, which severely limits their feasibility for multi-node micro-platform applications. Here, to address such a challenge, we propose a novel point-to-multipoint FSOC scheme based on reconfigurable SiC gratings, which are directly fabricated in stretchable PDMS films via femtosecond laser-induced carbide precipitation. The reconfigurable SiC transmission gratings are with good transparency (~91.9% at 1550 nm), dynamic beam steering capability (hundred-milliradian level), and an ultralightweight design (single grating: 0.4 g). The SiC fringes are specially fabricated within the internally symmetric region of the PDMS film to mitigate the structure distortion during stress regulation, significantly enhancing the long-range transmission capability in degraded atmospheric channels. The system supports 1-to-7 and 1-to-9 dynamic optical communication for 1D and 2D configurations, respectively. In a state-of-the-art 225-meter outdoor experiment, the system achieves reliable 10 Gbps transmission for each node. This portable FSOC system overcomes the limitations of conventional systems, enabling scalable and flexible multibeam steering. This approach establishes a robust foundation for long-range, multinode, and high-capacity FSOC networks among spatial micro-platforms such as unmanned aerial vehicles and micro-satellites.

We propose an all-optical wavelength converter for the mid-infrared spectral range with enhanced conversion efficiency. A highly nonlinear MXene-decorated microfiber is fabricated by the optical deposition method as the conversion medium, and the fiber exhibits a remarkable nonlinear optical response. We combine the benefits of the two-dimensional MXene materials and tapered microfiber to promote conversion efficiency. Homebuilt holmium-doped fiber lasers emitting at 2.05 μm wavelength are used as pump and signal sources. The experimental conversion efficiency observed by the optical spectrum analyzer is measured at –27.22 dB. This optical device allows an arbitrary tuning range of 17 nm. The fluctuations of the conversion efficiency remain within 1 dB during 2 h. The results of this study may contribute to the realization of optical converter application in the all-optical network at 2 μm wavelength.

We report on the switchable generation of a dissipative soliton (DS) pulse and a noise-like pulse (NLP) in an all-fiberized Tm-doped fiber laser in the normal-dispersion region. Mode-locking operation is achieved through a nonlinear polarization rotation component, and the cavity dispersion is compensated using ultra-high numerical aperture (UHNA4) fiber that is easy to integrate and low in cost. At a pump threshold of 510 mW, DS operation can first be achieved without additional filter. The 3 dB spectrum bandwidth of the DS pulse is greater than 50 nm, and the duration of the de-chirped pulse is 193 fs. By increasing the pump power to 880 mW, the mode-locking state can evolve into NLP operation with proper cavity polarization state. The 3 dB spectrum bandwidth and duration of de-chirped coherence spike are 105.6 nm and 121 fs, respectively. Meanwhile, ultra-broadband NLP (over 150 nm considering 3 dB spectrum width) can also be observed with the appropriate cavity parameters. All the proposed pulse patterns present good capacity for achieving narrow pulse width and withstanding high pulse energy.

Nanosecond dissipative soliton resonance pulse is a demonstration of an all polarization-maintaining (PM) thulium-doped fiber laser in a nonlinear amplifying loop mirror (NALM)-based figure-eight configuration. Each loop of the apparatus includes a controllable power amplifier. With increased amplifier power, pulse width broadens linearly from 3.6 to 13.5 ns, and maximum single pulse energy can reach 27.5 nJ. Interestingly, the output peak power presents two completely opposite proportional effects in terms of the variation of settings for two amplifiers, respectively. The experimental results show that the NALM loop plays an important role for tunable pulse duration, and the unidirectional ring part makes a significant contribution for power scaling.

With the development of all‐optical networks, all‐optical devices have become a research hotspot in recent years. Two‐dimensional materials, represented by graphene and black phosphorus, have attracted great interest in the scientific community due to their excellent optical, electrical, magnetic, and mechanical properties. Bridging the gap between fiber optics and nanotechnology, microfibers can interact with light and matter at the micro or even nanoscale. By combining two‐dimensional materials with microfibers, composite waveguides can be formed. They have the advantages of high nonlinear effect, all‐fiber structure, and high damage threshold, etc. The composite waveguide can be directly applied to optical fiber communication systems, and plays an important role in the field of all‐optical signal processing with a huge application prospect. In this review, the properties of typical 2D materials are first introduced. Next, the preparation methods of the relevant equipments are introduced and compared. Then, the all‐optical signal processing technology based on 2D material‐integrated microfiber composite waveguide is reviewed. The latest developments of all‐optical modulators, all‐optical wavelength converters, all‐optical logic gates and all‐optical thresholding devices are presented. Finally, the challenges and opportunities for the future development of 2D materials‐integrated microfiber optoelectronic devices are summarized.