Large-signal modulation capability, as an important performance indicator, is directly related to the high-speed optical communication technology involved. We experimentally and theoretically investigate the large-sig...Large-signal modulation capability, as an important performance indicator, is directly related to the high-speed optical communication technology involved. We experimentally and theoretically investigate the large-signal modulation characteristics of the simultaneous ground-state （GS） and the excited-state （ES） lasing in InAs/OaAs quantum dot laser diodes. The large-signal modulation capability of total light intensity in the transition regime from OS lasing to two-state lasing is unchanged as the bias-current increases. However, GS and ES large-signal eye diagrams show obvious variations during the transition. Relaxation oscillations and large-signal eye diagrams for OS, ES, and total light intensities are numerically simulated and analyzed in detail by using a rate-equation model. The -ndings show that a complementary relationship between the light intensities for OS and ES lasing exists in both the transition regime and the two-state lasing regime, leading to a much smaller overshooting power and a shorter settling time for the total light intensity. Therefore, the eye diagrams of GS or ES lasing are diffuse whereas those of total light intensity are constant as the bias-current increases in the transition regime.展开更多
Stimulus-driven color-change films are a basic optical component for the fabrication of a stimulus-driven color-change optical device.The practical application of this device is greatly affected by the performance of ...Stimulus-driven color-change films are a basic optical component for the fabrication of a stimulus-driven color-change optical device.The practical application of this device is greatly affected by the performance of the stimulus-driven color-change film.Herein,we present the W_(18)O_(49)honeycomb mesoporous pattern(HMP)film with excellent electrochromic performance.The W_(18)O_(49)HMP film is prepared on a flexible substrate(indium tin oxide-coated polyethylene terephthalate polyester film,ITO-PET)by integrating the polymer-like ultrathin W_(18)O_(49)nanowires(NWs)through the classical static breath figure method.By altering the concentration of the W_(18)O_(49)NW dispersion,the pore size of the obtained W_(18)O_(49)HMP film can be facilely tuned;this results in tunable optical modulation.The obtained W_(18)O_(49)HMP film exhibits improved electrochromic properties with an optimized optical modulation of 73%,fast switching time,high coloration efficiency,and high stability even under deformation.The presented method for the fabrication of size-tunable flexible electrochromic films from ultrathin polymer-like NWs can be further extended to the fabrication of various NW-based flexible devices in the future.展开更多
Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal,although having a fixed absorption performance limits their applicability.Here,a simple,transparent...Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal,although having a fixed absorption performance limits their applicability.Here,a simple,transparent,and thermally tunable microwave absorber is proposed,based on a patterned vanadium dioxide(VO_(2))film.Numerical calculations and experiments demonstrate that the proposed VO_(2)absorber has a high optical transmittance of 84.9%at 620 nm;its reflection loss at 15.06 GHz can be thermally tuned from–4.257 to–60.179 dB,and near-unity absorption is achieved at 523.750 K.Adjusting only the patterned VO_(2)film duty cycle can change the temperature of near-unity absorption.Our VO_(2)absorber has a simple composition,a high optical transmittance,a thermally tunable microwave absorption performance,a large modulation depth,and an adjustable temperature tuning range,making it promising for application in tunable sensors,thermal emitters,modulators,thermal imaging,bolometers,and photovoltaic devices.展开更多
Research on novel ultrafast photonic devices with wide adaptability has become important scientific technical means to realize both scheme innovation and performance breakthrough in fiber laser generation.As types of ...Research on novel ultrafast photonic devices with wide adaptability has become important scientific technical means to realize both scheme innovation and performance breakthrough in fiber laser generation.As types of transition metal oxide,manganese dioxide(MnO_(2))materials exhibit remarkable properties including high photothermal stability,strong oxidation resistance,and excellent optical properties,making them promising candidate for utilization as modulation devices in nonlinear optics and ultrafast optics fields.We investigate the impact of MnO_(2)-based saturable absorber(SA)on the pulse characteristics.The experiment reveals that MnO_(2)-based SA supports effectively pulsed laser generation in wide pump power range and large dispersion parameter space with signal-to-noise ratio more than 85 dB.As far as we know,the pump power response range is outstanding among the most of the reported pulsed lasers,which is attributed to the large modulation depth of MnO_(2) SA.We also investigate the impact of dispersion on the characteristics of laser output,which is not involved in other similar works.This research indicates that MnO_(2) as a photonic device has vast potential in advanced ultrafast optics.展开更多
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFB0402302the National Natural Science Foundation of China under Grant No 91433206
文摘Large-signal modulation capability, as an important performance indicator, is directly related to the high-speed optical communication technology involved. We experimentally and theoretically investigate the large-signal modulation characteristics of the simultaneous ground-state （GS） and the excited-state （ES） lasing in InAs/OaAs quantum dot laser diodes. The large-signal modulation capability of total light intensity in the transition regime from OS lasing to two-state lasing is unchanged as the bias-current increases. However, GS and ES large-signal eye diagrams show obvious variations during the transition. Relaxation oscillations and large-signal eye diagrams for OS, ES, and total light intensities are numerically simulated and analyzed in detail by using a rate-equation model. The -ndings show that a complementary relationship between the light intensities for OS and ES lasing exists in both the transition regime and the two-state lasing regime, leading to a much smaller overshooting power and a shorter settling time for the total light intensity. Therefore, the eye diagrams of GS or ES lasing are diffuse whereas those of total light intensity are constant as the bias-current increases in the transition regime.
基金National Nature Science Foundation of China(21771154,21503175,31371005,21401153)Shenzhen Fundamental Research Programs(JCYJ20170306142105928)+1 种基金Natural Science Foundation of Fujian Province of China(No.2018J01019)Fundamental Research Funds for the Central Universities(20720180019,20720180016)。
文摘Stimulus-driven color-change films are a basic optical component for the fabrication of a stimulus-driven color-change optical device.The practical application of this device is greatly affected by the performance of the stimulus-driven color-change film.Herein,we present the W_(18)O_(49)honeycomb mesoporous pattern(HMP)film with excellent electrochromic performance.The W_(18)O_(49)HMP film is prepared on a flexible substrate(indium tin oxide-coated polyethylene terephthalate polyester film,ITO-PET)by integrating the polymer-like ultrathin W_(18)O_(49)nanowires(NWs)through the classical static breath figure method.By altering the concentration of the W_(18)O_(49)NW dispersion,the pore size of the obtained W_(18)O_(49)HMP film can be facilely tuned;this results in tunable optical modulation.The obtained W_(18)O_(49)HMP film exhibits improved electrochromic properties with an optimized optical modulation of 73%,fast switching time,high coloration efficiency,and high stability even under deformation.The presented method for the fabrication of size-tunable flexible electrochromic films from ultrathin polymer-like NWs can be further extended to the fabrication of various NW-based flexible devices in the future.
基金support from the National Natural Science Foundation of China(61975046)。
文摘Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal,although having a fixed absorption performance limits their applicability.Here,a simple,transparent,and thermally tunable microwave absorber is proposed,based on a patterned vanadium dioxide(VO_(2))film.Numerical calculations and experiments demonstrate that the proposed VO_(2)absorber has a high optical transmittance of 84.9%at 620 nm;its reflection loss at 15.06 GHz can be thermally tuned from–4.257 to–60.179 dB,and near-unity absorption is achieved at 523.750 K.Adjusting only the patterned VO_(2)film duty cycle can change the temperature of near-unity absorption.Our VO_(2)absorber has a simple composition,a high optical transmittance,a thermally tunable microwave absorption performance,a large modulation depth,and an adjustable temperature tuning range,making it promising for application in tunable sensors,thermal emitters,modulators,thermal imaging,bolometers,and photovoltaic devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.12164030)Young Science and Technology Talents of Inner Mongolia(Grant No.NJYT22101)the Central Government Guides Local Science and Technology Development Fund Projects(Grant No.2023ZY0005).
文摘Research on novel ultrafast photonic devices with wide adaptability has become important scientific technical means to realize both scheme innovation and performance breakthrough in fiber laser generation.As types of transition metal oxide,manganese dioxide(MnO_(2))materials exhibit remarkable properties including high photothermal stability,strong oxidation resistance,and excellent optical properties,making them promising candidate for utilization as modulation devices in nonlinear optics and ultrafast optics fields.We investigate the impact of MnO_(2)-based saturable absorber(SA)on the pulse characteristics.The experiment reveals that MnO_(2)-based SA supports effectively pulsed laser generation in wide pump power range and large dispersion parameter space with signal-to-noise ratio more than 85 dB.As far as we know,the pump power response range is outstanding among the most of the reported pulsed lasers,which is attributed to the large modulation depth of MnO_(2) SA.We also investigate the impact of dispersion on the characteristics of laser output,which is not involved in other similar works.This research indicates that MnO_(2) as a photonic device has vast potential in advanced ultrafast optics.
