Few-layer Ti_(3)CN MXene for ultrafast photonics applications in visible band

Ti_(3)CN,as a typical hetero-MXene,has attracted tremendous attention for its unique properties.However,its ultrafast photonics applications are still rare.Here,the few-layer Ti_(3)CN MXene was successfully prepared by selective etching and molecular delamination technique.The nonlinear optical response of few-layer Ti_(3)CN MXene at 640 nm was studied using the open-aperture Z-scan technique.The asprepared Ti_(3)CN MXene sample exhibited excellent nonlinear saturable absorption characteristics,resulting in the nonlinear absorption coefficient b of
4.05×10^(-2)cm/GW,which was one order of magnitude larger than that of black phosphorus(BP)and molybdenum disulfide(MoS_(2)).For the optical modulation applications of few-layer Ti_(3)CN MXene,passively Q-switched(PQS)solid-state visible lasers based on Ti_(3)CN saturable absorber(SA)at 522 nm,607 nm,639 nm,and 721 nm were successfully realized.Furthermore,a Ti_(3)CN-based stable passively mode-locked Pr:YLF red laser was also successfully achieved with a pulse duration of 30 ps,and the corresponding repetition rate was 73.1 MHz.The optical modulation device based on few-layer Ti_(3)CN MXene shows good performance.Our work demonstrates that the tremendous prospects of the few-layer Ti_(3)CN MXene as a visible optical modulation device in ultrafast photonics applications.

Highly efficient dual-wavelength acousto-optically Q-switched Tm,La:CaF_(2)laser

A highly efficient milli-joule-level Q-switched Tm,La:CaF_(2)laser is experimentally demonstrated.By employing an acousto-optic modulator,the diode-pumped pulsed lasers are stably operated at repetition rates ranging from 500 Hz to 10 kHz.Dual-wavelength operation of 1881.7 nm and 1888.5 nm is achieved with slope efficiency of 64.7%.Up to 1.89 mJ of pulse energy is obtained at a pulse width of 100 ns,corresponding to a peak power of 18.88 kW.These results verified that the Tm,La:CaF_(2)crystal could be a promising candidate for achieving highly efficient and high-energy pulsed lasers.

Graphdiyne as a saturable absorber for 2-µm all-solid-state Q-switched laser

As a novel one-atom-thick carbon allotrope,graphdiyne(GDY)has attracted wide interest in two-dimensional materials owing to its unique feature with a planar layer comprising sp2-and sp-hybridized carbon atoms and a direct natural bandgap.A high-quality saturable absorber(SA)based on GDY was successfully fabricated,and the nonlinear saturable absorption properties were investigated.A compact diode-pumped solid-state passively Q-switched laser based on the as-prepared GDY-SA could be operated at 2µm.The Q-switched laser delivered a maximum average output power of 1.29 W at a central wavelength of 1908.41 nm with up to 54.8%slope efficiency.A repetition rate of 91.58 kHz and single pulse energy of 23.08µJ were obtained.This work is the first application of GDY as an SA to generate all-solid-state pulsed lasers.These results indicate that GDY is a promising SA for solid-state pulsed lasers and has further application potential for ultrafast photonic devices in the 2-µm region.

Broadband nonlinear optical response of graphdiyne for mid-infrared solid-state lasers

Graphdiyne(GDY),a novel all-carbon nanomaterial,is considered the most easily synthesized and stable carbon allotrope,positioning it as a promising photoelectric material.Herein,we successfully fabricated a high-quality GDY saturable absorber and saturable absorber mirror.Both broadband nonlinear saturable absorption and ultrafast relaxation dynamic properties in midinfrared region of the GDY were investigated.All solid-state diode-pumped short and ultrashort pulsed lasers were realized using the GDY absorber at wavelengths of 2 and 2.8μm,respectively.The results were then theoretically analyzed.This is the first presentation of ultrashort pulsed lasers in the mid-infrared region with GDY absorbers.These results resolutely confirm that GDY could be an optional broadband SA for all solid-state mid-infrared pulsed lasers,and they evidence its promising applications in mode-locked ultrafast lasers.

Graphene oxide for diode-pumped Tm:YLF passively Q-switched laser at 2 μm

A diode-pumped Tm:YLF passively Q-switched laser at 2μm was first demonstrated by using graphene oxide(GO)as a saturable absorber(SA).In this letter,continuous-wave(CW)laser and pulse laser performances were studied meticulously and systematically.It reasonably showed the dependence of the pulse duration,pulse energy,and pulse repetition rate on the absorbed power.A maximum repetition rate of 38.33 kHz and a single pulse energy of 9.89μJ were obtained.

Silver nanorods absorber for passively Q-switched Nd,Gd:CaF_(2) laser

Using a novel silver nanorods absorber with a localized surface plasmon resonance absorption peak at 1.06μm,we obtain a diode-pumped passively Q-switched(PQS)Nd,Gd:CaF_(2) disordered crystal laser output.Its PQS pulse laser performances are studied comprehensively and systematically in this Letter.The single pulse energy and peak power can be attained to 2.15μJ and 2.06 W,respectively.