A new method called multi-frequency holography (MFH) for two-dimensional radar cross-section imaging of rotating objects is introduced, in which a constant coherent reference signal from transmitted signal is added in...A new method called multi-frequency holography (MFH) for two-dimensional radar cross-section imaging of rotating objects is introduced, in which a constant coherent reference signal from transmitted signal is added into received signal over certain frequency-width. With the MFH only the intensity of received composite signals needs to be measured. Both imaging situations of far field and near field are considered in details. Special restrictions about the MFH are also discussed and simulated by numerical computation. Examples of numerical simulation show that the method is effective, applicable and perspective.展开更多
Optical phase conjugation(OPC)is a technique that generates a light field with reversed wavefront and identical amplitude distribution as the incident light.It has a unique feature of suppressing the aberration of inc...Optical phase conjugation(OPC)is a technique that generates a light field with reversed wavefront and identical amplitude distribution as the incident light.It has a unique feature of suppressing the aberration of incident beam induced by inhomogeneous or disturbing medium.Although this technique has been extensively studied since the 1970s,it has become more attractive because of unprecedented achievements and prospective potentials in biomedical applications.OPC-based techniques have been successfully utilized to form a focus through/inside highly scattered biological samples.It opens a new avenue by significantly enhancing the light delivery in biological tissue for high-resolution imaging,diagnosis and treatment of medical diseases.In order to provide insight into its further development,recent progress of OPC techniques for focusing light through/inside biological tissue was summarized.展开更多
文摘A new method called multi-frequency holography (MFH) for two-dimensional radar cross-section imaging of rotating objects is introduced, in which a constant coherent reference signal from transmitted signal is added into received signal over certain frequency-width. With the MFH only the intensity of received composite signals needs to be measured. Both imaging situations of far field and near field are considered in details. Special restrictions about the MFH are also discussed and simulated by numerical computation. Examples of numerical simulation show that the method is effective, applicable and perspective.
文摘Optical phase conjugation(OPC)is a technique that generates a light field with reversed wavefront and identical amplitude distribution as the incident light.It has a unique feature of suppressing the aberration of incident beam induced by inhomogeneous or disturbing medium.Although this technique has been extensively studied since the 1970s,it has become more attractive because of unprecedented achievements and prospective potentials in biomedical applications.OPC-based techniques have been successfully utilized to form a focus through/inside highly scattered biological samples.It opens a new avenue by significantly enhancing the light delivery in biological tissue for high-resolution imaging,diagnosis and treatment of medical diseases.In order to provide insight into its further development,recent progress of OPC techniques for focusing light through/inside biological tissue was summarized.
