A compressed terahertz imaging method using a terahertz time domain spectroscopy system(THz-TDSS)is suggested and demonstrated.In the method,a parallel THz wave with the beam diameter 4 cm from a usual THz-TDSS is use...A compressed terahertz imaging method using a terahertz time domain spectroscopy system(THz-TDSS)is suggested and demonstrated.In the method,a parallel THz wave with the beam diameter 4 cm from a usual THz-TDSS is used and a square shaped 2D echelon is placed in front of an imaged object.We confirm both in simulation and in experiment that only one terahertz time domain spectrum is needed to image the object.The image information is obtained from the compressed THz signal by deconvolution signal processing,and therefore the whole imaging time is greatly reduced in comparison with some other pulsed THz imaging methods.The present method will hopefully be used in real-time imaging.展开更多
Mutually-pumped phase conjugation in BaTiO3 crystal with two coherent incident beams has been studied experimentally for the bridge configuration. We observed that when the two pump beams are blocked individually, the...Mutually-pumped phase conjugation in BaTiO3 crystal with two coherent incident beams has been studied experimentally for the bridge configuration. We observed that when the two pump beams are blocked individually, the transient behavior of the phase conjugation reflectivity with coherent beams was greatly different from that with incoherent beams. The phase conjugate reflectivity was sensitive to small perturbations such as vibration, exhibiting a change of as much as a factor of 10. The response time to the vibration was measured to be about 0.3s.展开更多
Recently it has been found that the entire basin of a given attractor is riddled with"lioles^leading to another attractor.Here we present the first physical system-the laser cooled ions in a Paul trap that exhibi...Recently it has been found that the entire basin of a given attractor is riddled with"lioles^leading to another attractor.Here we present the first physical system-the laser cooled ions in a Paul trap that exhibits riddled basins in frequency-locking attractor.展开更多
基金Supported by the Natural Science Foundation of Beijing under Grant No 4102016the Science and Technology Program of Beijing Educational Committee under Grant No KM200910028005the National Basic Research Program of China under Grant Nos 2007CB310408,2006CB302901。
文摘A compressed terahertz imaging method using a terahertz time domain spectroscopy system(THz-TDSS)is suggested and demonstrated.In the method,a parallel THz wave with the beam diameter 4 cm from a usual THz-TDSS is used and a square shaped 2D echelon is placed in front of an imaged object.We confirm both in simulation and in experiment that only one terahertz time domain spectrum is needed to image the object.The image information is obtained from the compressed THz signal by deconvolution signal processing,and therefore the whole imaging time is greatly reduced in comparison with some other pulsed THz imaging methods.The present method will hopefully be used in real-time imaging.
基金the National Natural Science Foundation of China under Grant No.19674067.
文摘Mutually-pumped phase conjugation in BaTiO3 crystal with two coherent incident beams has been studied experimentally for the bridge configuration. We observed that when the two pump beams are blocked individually, the transient behavior of the phase conjugation reflectivity with coherent beams was greatly different from that with incoherent beams. The phase conjugate reflectivity was sensitive to small perturbations such as vibration, exhibiting a change of as much as a factor of 10. The response time to the vibration was measured to be about 0.3s.
基金Supported by the National Natural Science Foundation of China,and Nonlinear Science Project of C liina.
文摘Recently it has been found that the entire basin of a given attractor is riddled with"lioles^leading to another attractor.Here we present the first physical system-the laser cooled ions in a Paul trap that exhibits riddled basins in frequency-locking attractor.
