Broadband rhenium disulfide optical modulator for solid-state lasers  

作　　者：XIANCUI SU BAITAO ZHANG YIRAN WANG GUANBAI HE GUORU LI NA LIN KEJIAN YANG JINGLIANG HE SHANDE LIU 

机构地区：[1]State Key Laboratory of Crystal Materials,Shandong University [2]College of Electronics,Communication,and Physics,Shandong University of Science and Technology

出　　处：《Photonics Research》2018年第6期498-505,共8页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(NSFC)(51321091,61505098,61575110,61675116);Young Scholars Program of Shandong University(SDU)(2017WLJH48)

摘　　要：Rhenium disulfide （ReS2）, a member of group VII transition metal dichalcogenides （TMDs）, has attracted increasing attention because of its unique distorted 1T structure and electronic and optical properties, which are much different from those of group VI TMDs （MoS2, WS2, MoSeg, WSe2, etc.）. It has been proved that bulk ReS2 behaves as a stack of electronically and vibrationally decoupled monulayers, which offers remarkable possibilities to prepare a monolayer ReS2 facilely and offers a novel platform to study photonic properties of TMDs. However, due to the large and layer-independent bandgap, the nonlinear optical properties of ReS2 from the visible to midinfrared spectral range have not yet been investigated. Here, the band structure of ReS2 with the introduction of defects is simulated by the ab initio method, and the results indicate that the bandgap can be reduced from 1.38 to 0.54 eV with the introduction of defects in a suitable range. In the experiment, using a bulk ReS2 with suitable defects as the raw material, a few-layered broadband ReS2 saturable absorber （SA） is prepared by the liquid phase exfoliation method. Using the as-prepared ReS2 SA, passively Q-switched solid-state lasers at wavelengths of 0.64, 1.064, and 1.991 μm are investigated systematically. Moreover, with cavity design, a femtosecond passively modelocked laser at 1.06μm is successfully realized based on the as-prepared ReS2 SA for the first time. The results present a promising alternative for a rare broadband optical modulator and indicate the potential of ReS2 in generating Q-switched and mode-locked pulsed lasers. It is further anticipated that this work may be helpful for the design of 2D optoelectronic devices with variable bandgaps.Rhenium disulfide(ReS_2), a member of group Ⅶ transition metal dichalcogenides(TMDs), has attracted increasing attention because of its unique distorted 1T structure and electronic and optical properties, which are much different from those of group Ⅵ TMDs(MoS_2, WS_2, MoSe_2, WSe_2, etc.). It has been proved that bulk ReS_2 behaves as a stack of electronically and vibrationally decoupled monolayers, which offers remarkable possibilities to prepare a monolayer ReS_2 facilely and offers a novel platform to study photonic properties of TMDs. However,due to the large and layer-independent bandgap, the nonlinear optical properties of ReS_2 from the visible to midinfrared spectral range have not yet been investigated. Here, the band structure of ReS_2 with the introduction of defects is simulated by the ab initio method, and the results indicate that the bandgap can be reduced from 1.38 to 0.54 eV with the introduction of defects in a suitable range. In the experiment, using a bulk ReS_2 with suitable defects as the raw material, a few-layered broadband ReS_2 saturable absorber(SA) is prepared by the liquid phase exfoliation method. Using the as-prepared ReS_2 SA, passively Q-switched solid-state lasers at wavelengths of 0.64,1.064, and 1.991 μm are investigated systematically. Moreover, with cavity design, a femtosecond passively modelocked laser at 1.06 μm is successfully realized based on the as-prepared ReS_2 SA for the first time. The results present a promising alternative for a rare broadband optical modulator and indicate the potential of ReS_2 in generating Q-switched and mode-locked pulsed lasers. It is further anticipated that this work may be helpful for the design of 2D optoelectronic devices with variable bandgaps.

关 键 词：Nonlinear optical materials LASERS Q-SWITCHED LASERS SOLID-STATE Mode-locked lasers NANOMATERIALS 

分 类 号：TN1[电子电信—物理电子学]