Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microl...Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microlasers remains challenging.In this work,we address this challenge by demonstrating a tunable vertical cavity surface emitting laser(VCSEL)employing a tunable gain medium of halide phase-change perovskites-specifically MAPbI_(3) perovskite,sandwiched between two highly reflective mirrors composed of bottom-distributed Bragg reflectors(DBRs).This VCSEL possesses single-mode lasing emission with a low threshold of 23.5μJ cm^(−2) under 160 K,attributed to strong optical confinement in the high-quality(Q)cavity.Upon the phase change of MAPbI_(3) perovskite,both its gain and dielectric constant changes dramatically,enabling a wide(Δλ>9 nm)and temperature-sensitive(0.30 nm K^(−1) rate)spectral tunability of lasing mode in the near-infrared(N-IR)region.The laser displays excellent stability,demonstrating an 80%lifetime of>2.4×107 pulses excitation.Our findings may provide a versatile platform for the next generation of tunable coherent light sources.展开更多
Traditional light sources cannot emit an electromagnetic(EM)field with an orbital angular momentum(OAM),limiting their applications in modern optics.The recent development of the OAM laser,mainly based on micro-and na...Traditional light sources cannot emit an electromagnetic(EM)field with an orbital angular momentum(OAM),limiting their applications in modern optics.The recent development of the OAM laser,mainly based on micro-and nanostructures,can satisfy the increasing requirements for on-chip photonics and information capacities.Nevertheless,the photonic structures have fixed parameters that prevent these OAM lasers from being dynamically tuned.Here,we propose tunable vortex lasing from a microring cavity integrated by a phase change material,Ge_(2)Sb_(2)Te_(5)(GST225).By modulating the complex refractive index to create an exceptional point(EP)to break the degeneracy of whispering gallery modes with opposite orientations,the microlaser working at the EP can impart an artificial angular momentum,thus emitting vortex beams with well-defined OAM.The grating scatter on the edge of the microring can provide efficient vertical radiation.The vortex laser wavelength from the GST225/InGaAsP dual-layered microring cavity can be dynamically tuned by switching the state of GST225 between amorphous and crystalline without changing the microring geometry.We construct an electric-thermal model to show the tuning range of operating wavelengths(EPs)from 1544.5 to 1565.9 nm in~25 ns.Our study on high-speed tunable PT-symmetry vortex lasers facilitates the next generation of integrated optoelectronic devices for optical computing and communications in both classical and quantum regions.展开更多
基金supported by the National Key Research and Development Program of China(2020YFA0714504,2019YFA0709100 to T.C.)the program of the National Natural Science Foundation of China(No.62105054 to T.C.)+1 种基金the New Cornerstone Science Foundation(AoE/P502/20 to S.Z.)the Research Grants Council of Hong Kong(17315522 to S.Z.).
文摘Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microlasers remains challenging.In this work,we address this challenge by demonstrating a tunable vertical cavity surface emitting laser(VCSEL)employing a tunable gain medium of halide phase-change perovskites-specifically MAPbI_(3) perovskite,sandwiched between two highly reflective mirrors composed of bottom-distributed Bragg reflectors(DBRs).This VCSEL possesses single-mode lasing emission with a low threshold of 23.5μJ cm^(−2) under 160 K,attributed to strong optical confinement in the high-quality(Q)cavity.Upon the phase change of MAPbI_(3) perovskite,both its gain and dielectric constant changes dramatically,enabling a wide(Δλ>9 nm)and temperature-sensitive(0.30 nm K^(−1) rate)spectral tunability of lasing mode in the near-infrared(N-IR)region.The laser displays excellent stability,demonstrating an 80%lifetime of>2.4×107 pulses excitation.Our findings may provide a versatile platform for the next generation of tunable coherent light sources.
基金The National Key Research and Development Program of China(2019YFA0709100.2020YFA0714504)the program of the National Natural Science Foundation of China(No.62105054)。
文摘Traditional light sources cannot emit an electromagnetic(EM)field with an orbital angular momentum(OAM),limiting their applications in modern optics.The recent development of the OAM laser,mainly based on micro-and nanostructures,can satisfy the increasing requirements for on-chip photonics and information capacities.Nevertheless,the photonic structures have fixed parameters that prevent these OAM lasers from being dynamically tuned.Here,we propose tunable vortex lasing from a microring cavity integrated by a phase change material,Ge_(2)Sb_(2)Te_(5)(GST225).By modulating the complex refractive index to create an exceptional point(EP)to break the degeneracy of whispering gallery modes with opposite orientations,the microlaser working at the EP can impart an artificial angular momentum,thus emitting vortex beams with well-defined OAM.The grating scatter on the edge of the microring can provide efficient vertical radiation.The vortex laser wavelength from the GST225/InGaAsP dual-layered microring cavity can be dynamically tuned by switching the state of GST225 between amorphous and crystalline without changing the microring geometry.We construct an electric-thermal model to show the tuning range of operating wavelengths(EPs)from 1544.5 to 1565.9 nm in~25 ns.Our study on high-speed tunable PT-symmetry vortex lasers facilitates the next generation of integrated optoelectronic devices for optical computing and communications in both classical and quantum regions.
