Ultrafast Laser Application Of Class Molybdenum Disulfide Material

Ultrafast laser possess unique ultra-short pulse with ps or fs of pulse duration time and high peak power at relatively low energy intensity.They have many practical applications in a great deal of field for investigating the delicate changes in super-fast process of chemical reactions,transient imaging,ultrafast optical switch,high precision large capacity optical communication system.In addition,its abundant spectroscopy compositions could deliver the spectral detection,pulse shaping,etc.Moreover,fiber laser possess many intrinsic advantages,such as excellent cooling performance,good beam quality,high pump conversion efficiency,compact structure for packaging and lower maintenance cost,etc.,which above-mentioned have capture great interest from researchers.There are two major technologies for achievement ultra-short pulse fiber lasers,active mode-locked and passive mode-locked techniques.Comparing extra components in active mode-locked technique,only an intra-cavity nonlinear optical modulator for passive mode-locking makes structure greatly simple and be used pervasively.The optical modulator is a saturable absorber(SA),which could be divided into class SA(e.g.NPR)and intrinsic SA(e.g.SESAM,CNTs).Recently,two dimensional layered materials(e.g.graphene,TMDs,and BP)have triggered rapid growing interest duo to their remarkable optoelectronic properties.It is an ultimate aim,using the material SA aforesaid to produce pulses with narrow duration,high frequency,large energy and academic research of soliton dynamics in fiber lasers.MoS2,one typical shining material of TMDs,possess layer-dependent band gap characteristics.Majority TMDs materials and BP(e.g.BP nano sheet,BPQDs,PQDs)could be called class MoS2 materials for their same band gap characteristics.Here,we investigate the optical nonlinearities of MoS2,BPQDs and PQDs,and obtain ultra-fast pulses.The main research achievements list as follow:1.Here,the "lateral interaction scheme" is employed to solve the issue of low laser damage threshold of few-layer MoS2.To our known,it is the first time dropping few-layer MoS2 suspension onto a taper fiber and drying in room temperature,where the laser beam interact with MoS2 material through the evanescent field.Based on the component as a SA,a mode-locked and Q-switching mode-locked pulse Yb-doped fiber laser is achieved with favorable stability.This scheme allows it to survive with an incident continuous laser power higher than 1 W,which also increase the interaction distance between few-layer MoS2 and the enanescent field,improve the modulated ability to light field,enhance cooling process and have great potential to research multi-soliton states with big nonlinear polarizability.Considering a number of MoS2-liked layered TMDs,we offer an effective approach to defuse the problem of low laser damage threshold.2.The bandgap of BP can be tuned from 0.3 ev to 2 ev,and thus holds great promising in bridging the gap between zero-bandgap graphene and large-bandgap TMDs(1-2 eV).More important,BP is direct band gap under any layer structure,which could improve the effect direct interaction with optical field.BPQDs possess uniform appearance and diameter size,even more superior optical saturable absorption properties than BP nanosheets.Here,we optical deposit BPQDs materials onto homemade taper fiber for the first time,meanwhile accompany with a constant temperature stage to prolong the material working time.The ultra-short pulses in communication band Er-doped fiber laser are generated.This work highlights that this 2D materials as SAs could leverage benefits in short-pulse fiber laser technology.3.PQDs are 1-2 few-layers,with unique diameter size,bandgaps and prospect desirable photonic performance.However,there is no report on investigating the nonlinear optical response of PQDs in the near infrared region,speciously at 1550 nm,and its applicability as a potential SA device to produce ultrashort pulses in this spectral region.We fabricate creatively a based PQDs taper fiber SA,and then produce fs pulses and polarization-locked vector solitons from an Er-doped fiber laser with excellent stability.This experiment indicates that this nanomaterial could be a promising two dimensional SA candidate for ultrafast optics,and an ideal platform for academic research of various soliton dynamics.Its unique optical properties promise to shape the future of ultra-short pulse fiber lasers.