Graphdiyne has an inborn band gap energy, where the minimal band gap is about from 0.46 to 1.22 eV, which shows great potential in ultrafast laser generation. In this work, we fabricate a graphdiyne-decorated microfiber and demonstrate its saturable absorption characteristics experimentally. This device is used as a saturable absorber to generate the conventional soliton and noise-like pulse in an erbium-doped mode-locked fiber laser. The conventional soliton with a spectral bandwidth of 2.45 nm can switch into noise-like pulse with 37.14 nm bandwidth by adjusting the pump power and the polarization controller. For the noise-like pulse, the mode-locked state has excellent stability with 2.17 nJ maximum pulse energy and 283 fs coherent peak duration. This work indicates that graphdiyne could be a remarkable nonlinear photonic device to explore the dynamics of various mode-locked pulses.

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.

A 2 μm band active mode-locked fiber laser with 3m thulium-holmium co-doped fiber as gain medium is reported. According to the cavity length, the fundamental frequency is 12.24 MHz and two MZM modulators are used to obtain pulse sequences and spectrum of different repetition frequencies. When the stable repetition frequency is 489.7 MHz, the signal-to-noise ratio is 62.32 dB and the 3 dB bandwidth is 0.09 nm. A mode-locked pulse carrier of 489.7 Mb/s was obtained by synchronous digital modulation, the signal-to-noise ratio of the measured eye image was 11.1 dB. I.IntroductionIn recent decades, due to the needs of equipment production and the development of science and technology, 2 μm fiber laser has been widely valued and developed especially in the medical, beauty and other fields.[1] The 2 μm band is in the safe band of human eyes, it covers the high

All-optical wavelength conversion technology based on two-dimensional (2D) materials has lately received keen interest. As a new 2D material, borophene displays acceptable photoelectric properties. We demonstrate the all-optical wavelength conversion through four-wave mixing (FWM) in borophene-microfiber hybrid waveguides. Borophene is deposited at the thinnest part of the tapered fiber and enhanced FWM occurs in this photonic device. By optimizing the effect of nonlinear polarization, wavelength tuning, and power variation, the conversion efficiency increases to − 19.1 d B , corresponding to 3 dB conversion bandwidth in a range of 7.1 nm. In addition, this photonic device is employed to achieve all-optical wavelength conversion of 10 Gb/s non-return-to-zero digital sequence. The signal quality of converted light such as optical signal-to-noise ratio, bit-error-rate, and eye diagram are investigated, which indicates that the proposed wavelength converter has high conversion efficiency and remarkable stability. This study shows that the borophene-microfiber waveguide has potential application prospects in all-optical signal processing.

An all-optical wavelength converter based on graphene oxide (GO) is proposed at the 1.9 µm band. The homemade GO-coated microfiber is acquired through the optical deposition method, which shows a remarkable nonlinear optical response. Stable conversion efficiency up to −45.52 dB is obtained with 1 nm wavelength interval, and the wavelength tuning range can reach 6 nm (1969-1975 nm). With fixed wavelength interval, the conversion efficiency can increase with the increase of pump power. Simultaneously, the fluctuation of conversion efficiency is ±0.41 dB within 2 hours. The demonstrated all-optical wavelength converter based on GO can play an outstanding role in the future of all-optical communications and networks.