2D ternary transition metal dichalcogenides (TMDCs) have been studied widely by researchers from the fields of nanotechnology to materials science because of the extraordinary chemical/physical characteristics, and significant potential in nanoscale device applications. Here, the application of Nb x Re (1−x) S 2 nanosheets in ultrafast photonics is studied. The few-layer Nb x Re (1−x) S 2 nanosheets are fabricated through liquid phase exfoliation method and a Nb x Re (1−x) S 2 -microfiber device is constructed by depositing these nanosheets onto the tapered region of a microfiber. After incorporating the Nb x Re (1−x) S 2 -microfiber saturable absorber (SA) into a net positive dispersion Er-doped fiber (EDF) laser cavity, the generation of stable dissipative soliton pulses with a pulse duration of 1.03 ps proved as polarization-locked vector solitons upon further study. With pump power growing to 900 mW, the average output power increases to 116.9 mW without pulse splitting. Besides, the pulse width can be compressed to 149.6 fs outside the cavity by using a single-mode fiber. Compared with previous works based on 2D materials-based saturable absorbers, the Nb x Re (1−x) S 2 -based mode-locked fiber laser proposed herein, reveals superior comprehensive performance.

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We present a two-dimensional carpet cloak for static magnetic field, a design that renders the magnetic response of a given volume invisible from its exterior, without altering the external magnetic fields. The device is designed using transformation optics method and can be implemented with alternating superconducting and magnetic material layers. Through the proper design of the constitutive tensors and relative thicknesses of each slab, we achieve the perfect performance of invisibility. Full wave numerical simulations confirm our design.

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Two-dimensional (2D) transition metal chalcogenides (TMCs) become more attractive upon addition of a third element owing to their unique structure and remarkable physical and chemical properties, which endow these materials with considerable potential for applications in nanoscale devices. In this work, a Re x Nb(1–x)S2-based saturable absorber (SA) device for ultrafast photonics applications is studied. The device is assembled by placing Re x Nb(1–x)S2 nanosheets with a thickness of 1–3 nm onto a microfiber to increase their compatibility with an all-fiber laser cavity. The prepared Re x Nb(1–x)S2-based device exhibits a modulation depth of 24.3%, a saturation intensity of 10.1 MW/cm2, and a nonsaturable loss of 28.5%. Furthermore, the Re x Nb(1–x)S2-based device is used to generate ultrashort pulses in an erbium-doped fiber (EDF) laser cavity. At a pump power of 260 mW, the EDF laser operates in a conventional soliton mode-locked region. The pulse width is 285 fs, and the repetition frequency is 61.993 MHz. In particular, the bound-state soliton mode-locking operation is successfully obtained in a pump power range of 300–900 mW. The bound-state pulses are formed by doubling identical solitons with a temporal interval of 0.8 ps. The output power is as high as 47.9 mW, and the repetition frequency is 123.61 MHz. These results indicate that the proposed Re x Nb(1–x)S2-based SAs have comparable properties to currently used 2D SAs and provide a basis for their application in the field of ultrafast photonics.