CsPbBr3 nanocrystal for mode-locking Tm-doped fiber laser

CsPbBr3 nanocrystal is used as the saturable absorber(SA) for mode-locking Tm-doped fiber laser in a ring fiber cavity.The modulation depth, saturable intensity, and non-saturable loss of the fabricated SA are 14.1%, 2.5 MW/cm^2,and 5.9%, respectively.In the mode-locking operation, the mode-locked pulse train has a repetition rate of 16.6 MHz with pulse width of 24.2 ps.The laser wavelength is centered at 1992.9 nm with 3-dB spectrum width of 2.5 nm.The maximum output power is 110 mW with slope efficiency of 7.1%.Our experiment shows that CsPbBr3 nanocrystal can be used as an efficient SA in the 2-μm wavelength region.

Manipulating vector solitons with super-sech pulse shapes

Theoretical simulations about manipulating vector solitons with super-sech pulse shapes are conducted based on an optical fiber system.By changing the temporal pulses’parameters when the orthogonally polarized pulses have the same or different input central wavelengths,the output modes in orthogonal directions will demonstrate different properties.When the input orthogonal modes have the same central wavelength,the“2+2”pseudo-high-order vector soliton can be generated when the time delay is changed.While under the condition of different central wavelengths,orthogonal pulses with multiple peaks accompanied with two wavelengths can be achieved through varying the projection angle,time delay or phase difference.Our simulations are helpful to the study of optical soliton dynamics in optical fiber systems.

Polarization manipulation of bright-dark vector bisolitons

We simulate the polarization manipulation of bright-dark vector bisolitons at 1-µm wavelength regime.Through changing the pulse parameters,different kinds of pulse shapes and optical spectra are generated in output orthogonal polarization directions.When the input vector bisoliton is polarization-locked with 1064 nm central wavelength,“1+1”fundamental dark-dark and“2+1”pseudo-high-order bright-dark group-velocity-locked vector solitons can be achieved through changing the projection angle.When the input vector bisoliton is group-velocity-locked with 1063 nm and 1065 nm central wavelengths,“2+1”and“2+2”pseudo-high-order bright-dark group-velocity-locked vector solitons,bright-dark group-velocity-locked vector solitons with chirp-like temporal oscillations are generated.Our simulation results can provide beneficial conduct for polarization manipulation of vector multi-solitons,and have promising applications in quantum information register,optical communications,nanophotonics,and all-optical switching.

Pulse shaping of bright-dark vector soliton pair

We simulate pulse shaping of bright-dark vector soliton pair in an optical fiber system.Through changing input pulse parameters(amplitude ratio,projection angle,time delay,and phase difference),different kinds of pulse shapes and spectra can be generated.For input bright-dark vector soliton pair with the same central wavelength,“2+1”-and“2+2”-type pseudo-high-order bright-dark vector soliton pairs are achieved.While for the case of different central wavelengths,bright-dark vector soliton pairs with multiple pulse peaks/dips are demonstrated with appropriate pulse parameter setting.

Ultraflat, broadband, and highly coherent supercontinuum generation in all-solid microstructured optical fibers with all-normal dispersion

High flatness, wide bandwidth, and high-coherence properties of supercontinuum(SC) generation in fibers are crucial in many applications. It is challenging to achieve SC spectra in a combination of the properties, since special dispersion profiles are required, especially when pump pulses with duration over 100 fs are employed. We propose an all-solid microstructured fiber composed only of hexagonal glass elements. The optimized fiber possesses an ultraflat all-normal dispersion profile, covering a wide wavelength interval of approximately 1.55 μm. An SC spectrum spanning from approximately 1030 to 2030 nm(corresponding to nearly one octave) with flatness<3 dB is numerically generated in the fiber with 200 fs pump pulses at 1.55 μm. The results indicate that the broadband ultraflat SC sources can be all-fiber and miniaturized due to commercially achievable 200-fs fiber lasers. Moreover, the SC pulses feature high coherence and a single pulse in the time domain, which can be compressed to 13.9-fs pulses with high quality even for simple linear chirp compensation. The Fourier-limited pulse duration of the spectrum is 3.19 fs, corresponding to only 0.62 optical cycles.

Stimulated Brillouin scattering by the interaction between different-order optical and acoustical modes in an As2Se3 photonic crystal fiber

Brillouin gain spectra(BGS)in an As2Se3 photonic crystal fiber(PCF)are investigated numerically.The profiles of the BGS are simulated by calculating the characteristics of different-order optical and acoustic waves in the PCFs with different core diameters.For the small-core PCF,there are two peaks in BGS,but there is only one peak for the large-core PCF.We also reveal that in the small-core PCF,the difference of Brillouin frequency shift between the LP01 and LP11 modes is obvious,while it is not obvious in the large-core PCF.The Brillouin threshold increases with the core diameter increasing.