Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system ...Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided.展开更多
We report a cesium vapor laser with fundamental mode output and a wavelength of 894 nm. The laser is pumped by a laser diode array with an external cavity of a holographic grating by using Littrow＇s structure. A slop...We report a cesium vapor laser with fundamental mode output and a wavelength of 894 nm. The laser is pumped by a laser diode array with an external cavity of a holographic grating by using Littrow＇s structure. A slope efbciency of 22.4% is obtained by using a pumping source with a linewidth of 0.26 nm and 80 kPa methane as the buffer gas. The threshold pumping power is 1.56 W.展开更多
Ghost imaging and diffraction, inspired by the Hanbury Brown and Twiss effect, have potential in both classical and quantum optics regimes on account of their nonlocal characteristics and subwavelength resolution capa...Ghost imaging and diffraction, inspired by the Hanbury Brown and Twiss effect, have potential in both classical and quantum optics regimes on account of their nonlocal characteristics and subwavelength resolution capabil- ity, and therefore have aroused particular interest. By extending the correspondence imaging scheme, we utilize the positive and negative intensity correlations in diffraction and perform subwavelength diffraction with pseudo-thermal light. In the experiment, a subwavelength （λ/2） resolution and a better signal-to-noise ratio （10.3% improvement） are simultaneously achieved. The scheme can be utilized as a complement to the existing ghost imaging scheme to improve image quality.展开更多
In this Letter, we investigate a method for controlling the intensity of a light by another light in a periodically poled MgO-doped lithium niobate（PPMgLN） crystal with a transverse applied external electric field. ...In this Letter, we investigate a method for controlling the intensity of a light by another light in a periodically poled MgO-doped lithium niobate（PPMgLN） crystal with a transverse applied external electric field. The power of the emergent light can be modulated by the power ratio of the incident ordinary and extraordinary beams. The light intensity control is experimentally demonstrated by the Mach–Zehnder interference configuration, and the results are in good agreement with the theoretical predictions.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11175094 and 91221205)the National Basic Research Program of China(Grant No.2015CB921002)partially supported by the Basic Research Fund of Beijing Institute of Technology(Grant No.20141842005)
文摘Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided.
文摘We report a cesium vapor laser with fundamental mode output and a wavelength of 894 nm. The laser is pumped by a laser diode array with an external cavity of a holographic grating by using Littrow＇s structure. A slope efbciency of 22.4% is obtained by using a pumping source with a linewidth of 0.26 nm and 80 kPa methane as the buffer gas. The threshold pumping power is 1.56 W.
基金supported by the National Basic Research Program of China(No.2010CB922904)the National Natural Science Foundation of China (No.61307021)the China Scholarship Council (No.201306025016)
文摘Ghost imaging and diffraction, inspired by the Hanbury Brown and Twiss effect, have potential in both classical and quantum optics regimes on account of their nonlocal characteristics and subwavelength resolution capabil- ity, and therefore have aroused particular interest. By extending the correspondence imaging scheme, we utilize the positive and negative intensity correlations in diffraction and perform subwavelength diffraction with pseudo-thermal light. In the experiment, a subwavelength （λ/2） resolution and a better signal-to-noise ratio （10.3% improvement） are simultaneously achieved. The scheme can be utilized as a complement to the existing ghost imaging scheme to improve image quality.
基金supported in part by the National Basic Research Program of China(No.2011CB808101)the National Natural Science Foundation of China(Nos.61125503 and 61235009)the Foundation for the Development of Science and Technology of Shanghai(No.13JC1408300)
文摘In this Letter, we investigate a method for controlling the intensity of a light by another light in a periodically poled MgO-doped lithium niobate（PPMgLN） crystal with a transverse applied external electric field. The power of the emergent light can be modulated by the power ratio of the incident ordinary and extraordinary beams. The light intensity control is experimentally demonstrated by the Mach–Zehnder interference configuration, and the results are in good agreement with the theoretical predictions.
