A hybrid integrated low-noise linear chirp frequency-modulated continuous-wave(FMCW)laser source with a wide frequency bandwidth is demonstrated.By employing two-dimensional thermal tuning,the laser source shows frequ...A hybrid integrated low-noise linear chirp frequency-modulated continuous-wave(FMCW)laser source with a wide frequency bandwidth is demonstrated.By employing two-dimensional thermal tuning,the laser source shows frequency modulation bandwidth of 10.3 GHz at 100 Hz chirped frequency and 5.6 GHz at 1 kHz chirped frequency.The intrinsic linewidth of 49.9 Hz with 42 GHz continuous frequency tuning bandwidth is measured under static operation.Furthermore,by pre-distortion linearization of the laser source,it can distinguish 3 m length difference at 45 km distance in the fiber length measurement experiment,demonstrating its application potential in ultra-long fiber sensing and FMCW light detection and ranging.展开更多
Soft molecule-based ferroelectrics with unique structural flexibility hold apromise for versatile applications of non-volatile memory, imaging and photovoltaicdevices. Except for few polymers (e.g., polyvinylidene flu...Soft molecule-based ferroelectrics with unique structural flexibility hold apromise for versatile applications of non-volatile memory, imaging and photovoltaicdevices. Except for few polymers (e.g., polyvinylidene fluoride, PVDF),it is challenging to exploit soft ferroelectric crystals toward free-standing flexiblephotoactive devices. We here report a multiaxial soft molecule-based ferroelectric,(n-PA)_(2)PbCl_(4) (1, where n-PA^(+)is n-pentylammonium), of whichspontaneous polarization can be reversibly switched in both crystal and powderforms. Strikingly, single crystals of 1 have unusual structural flexibility andbendability, achieving the self-standing bending with a bending radius of0.22 mm. Besides, the pyroelectric activities are also preserved for these singlecrystals after several bending cycles. Further, the bendable crystal-basedphotodetector of 1 allows broadband photoactivities via the photo-pyroelectriceffect, covering a wide range from 405 to 940 nm spectral region, breakingthrough the limit of optical absorption bandgap. As the first study of bendablefree-standing photo-pyroelectric detectors in ferroelectric crystals, our worksheds light on the assembly of flexible smart photoelectric devices.展开更多
基金National Key Research and Development Program of China(2018YFB2201802)National Natural Science Foundation of China(61771285).
文摘A hybrid integrated low-noise linear chirp frequency-modulated continuous-wave(FMCW)laser source with a wide frequency bandwidth is demonstrated.By employing two-dimensional thermal tuning,the laser source shows frequency modulation bandwidth of 10.3 GHz at 100 Hz chirped frequency and 5.6 GHz at 1 kHz chirped frequency.The intrinsic linewidth of 49.9 Hz with 42 GHz continuous frequency tuning bandwidth is measured under static operation.Furthermore,by pre-distortion linearization of the laser source,it can distinguish 3 m length difference at 45 km distance in the fiber length measurement experiment,demonstrating its application potential in ultra-long fiber sensing and FMCW light detection and ranging.
基金National Natural Science Foundation of China,Grant/Award Numbers:22125110,U23A2094,22205233,22193042,21921001,U21A2069,22305248Natural Science Foundation of Fujian Province,Grant/Award Numbers:2023J02028,2023J01235+2 种基金Key Research Program of Frontier Sciences of Chinese Academy of Sciences,Grant/Award Number:ZDBSLY-SLH024Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China,Grant/Award Number:2021ZR126China Postdoctoral Science Foundation,Grant/Award Number:2023M733497。
文摘Soft molecule-based ferroelectrics with unique structural flexibility hold apromise for versatile applications of non-volatile memory, imaging and photovoltaicdevices. Except for few polymers (e.g., polyvinylidene fluoride, PVDF),it is challenging to exploit soft ferroelectric crystals toward free-standing flexiblephotoactive devices. We here report a multiaxial soft molecule-based ferroelectric,(n-PA)_(2)PbCl_(4) (1, where n-PA^(+)is n-pentylammonium), of whichspontaneous polarization can be reversibly switched in both crystal and powderforms. Strikingly, single crystals of 1 have unusual structural flexibility andbendability, achieving the self-standing bending with a bending radius of0.22 mm. Besides, the pyroelectric activities are also preserved for these singlecrystals after several bending cycles. Further, the bendable crystal-basedphotodetector of 1 allows broadband photoactivities via the photo-pyroelectriceffect, covering a wide range from 405 to 940 nm spectral region, breakingthrough the limit of optical absorption bandgap. As the first study of bendablefree-standing photo-pyroelectric detectors in ferroelectric crystals, our worksheds light on the assembly of flexible smart photoelectric devices.
