公开(公告)号：US09110022B2

公开(公告)日：2015-08-18

申请号：US13643871

申请日：2011-04-29

申请人： Benjamin Clough ,  Jingle Liu ,  Xi-Cheng Zhang

发明人： Benjamin Clough ,  Jingle Liu ,  Xi-Cheng Zhang

IPC分类号： G01N21/63 ,  G01N21/3504 ,  G01N21/3581

CPC分类号： G01N21/63 ,  G01N21/3504 ,  G01N21/3581

摘要： Methods and systems for detecting radiation for example, terahertz radiation, with the aid of acoustic signal generation and detection include: directing an optical beam into a volume of gas; ionizing at least a portion of the volume of gas with the optical beam to produce a plasma; and detecting an acoustic signal produced from an interaction of a radiation wave with the plasma. The methods and systems are particularly adapted for remote detection of chemicals, biological substances, and explosives, among others. The capability of the methods and systems can be enhanced by employing multi-color laser excitation to produce the plasma and varying the time delay between the multi-color pulses.

摘要翻译： 借助于声信号产生和检测，用于检测辐射的方法和系统，例如太赫兹辐射，包括：将光束引导到一定体积的气体中; 用光束电离至少一部分体积的气体以产生等离子体; 以及检测由辐射波与等离子体的相互作用产生的声信号。 这些方法和系统特别适用于远程检测化学品，生物物质和爆炸物等。 可以通过采用多色激光激发产生等离子体并改变多色脉冲之间的时间延迟来增强方法和系统的能力。

公开(公告)号：US08299435B2

公开(公告)日：2012-10-30

申请号：US12855332

申请日：2010-08-12

申请人： Xi-Cheng Zhang ,  Pengyu Han ,  Yuting W. Chen

发明人： Xi-Cheng Zhang ,  Pengyu Han ,  Yuting W. Chen

IPC分类号： G01J5/08

CPC分类号： G02B1/118

摘要： A broadband anti-reflection apparatus for use with terahertz radiation includes a layer having an outer surface comprising a plurality of pyramid structures having about a 30 μm to about a 110 μm period, and wherein reflectance of the terahertz radiation is reduced compared to a layer comprising a planar outer surface. Also disclosed is a method for modifying terahertz radiation which includes receiving terahertz radiation on a device having an anti-reflection layer having an outer surface comprising a plurality of pyramid structures having about a 30 μm to a 110 μm period, and modifying the terahertz radiation passing through the device or processing the terahertz radiation in the device.

摘要翻译： 一种与太赫兹辐射一起使用的宽带抗反射装置包括具有外表面的层，该层具有包括大约30μm至大约110μm周期的多个金字塔结构，并且与包括以下的层相比，太赫兹辐射的反射率降低： 平面外表面。 还公开了一种用于修改太赫兹辐射的方法，其包括在具有抗反射层的装置上接收太赫兹辐射，所述抗反射层具有外表面，该外表面包括具有约30μm至110μm周期的多个金字塔结构，并且修改太赫兹辐射通过 通过设备或处理设备中的太赫兹辐射。

公开(公告)号：US07718969B2

公开(公告)日：2010-05-18

申请号：US11756243

申请日：2007-05-31

申请人： Xi-Cheng Zhang ,  Jianming Dai ,  Xu Xie

发明人： Xi-Cheng Zhang ,  Jianming Dai ,  Xu Xie

IPC分类号： G01N21/35

CPC分类号： G01N21/3581 ,  G01N21/3563 ,  G01N21/636 ,  G01S7/4802 ,  G01S13/887 ,  G01S17/026

摘要： A method for generating amplified terahertz radiation includes inducing a first volume of a gas to produce a seed plasma and emit pulsed seed terahertz radiation by focusing an optical seed beam in the first volume. The seed terahertz radiation is then amplified by focusing an optical gain beam to produce a gain plasma in a second volume overlapping with the pulsed seed terahertz radiation remote from the seed plasma. The method may be implemented in a system for detecting and analyzing a remotely-located object such as an explosive material, a biological agent, and a chemical agent.

摘要翻译： 用于产生放大的太赫兹辐射的方法包括：通过将光学种子束聚焦在第一体积中来诱导第一体积的气体以产生种子等离子体并发射脉冲种子太赫兹辐射。 然后通过聚焦光学增益束来放大种子太赫兹辐射，以产生与远离种子等离子体的脉冲种子太赫兹辐射重叠的第二体积中的增益等离子体。 该方法可以在用于检测和分析诸如爆炸物质，生物制剂和化学试剂的远程定位物体的系统中实现。

公开(公告)号：US06977379B2

公开(公告)日：2005-12-20

申请号：US10434329

申请日：2003-05-08

申请人： Xi-Cheng Zhang ,  Jingzhou Xu ,  Tao Yuan

发明人： Xi-Cheng Zhang ,  Jingzhou Xu ,  Tao Yuan

IPC分类号： G01N21/35 ,  G02B21/00

CPC分类号： G01N21/3581 ,  G01N21/3563 ,  G02B21/00

摘要： A microscope for producing an image of a target using THz radiation. The microscope comprises a source for providing an optical pump pulse and an optical probe pulse; a THz emitter for activation by pump pulse to emit a THz pulse that irradiates the target to form a target-modified THz pulse; a THz detector for modulating the probe pulse with the target-modified THz pulse to create a modulated optical probe pulse characteristic of the target; an optical detection system for modifying and detecting the modulated optical probe pulse and converting the modulated optical probe pulse to electronic information; and a processor for receiving the electronic information and producing an image of the sample using the electronic information. The THz emitter and detector comprise one or more EO crystals. The target is positioned on one of the EO crystals in a near-field of the THz pulse.

摘要翻译： 用于使用太赫兹辐射产生目标图像的显微镜。 显微镜包括用于提供光泵浦脉冲和光探针脉冲的源; 用于通过泵浦脉冲激活的THz发射器发射照射目标以形成目标修正的THz脉冲的THz脉冲; THz检测器，用于用目标修正的THz脉冲调制探针脉冲，以产生目标的调制光探针脉冲特性; 光学检测系统，用于修改和检测调制的光探针脉冲并将调制的光探针脉冲转换成电子信息; 以及处理器，用于接收电子信息并使用电子信息产生样本的图像。 太赫兹发射器和检测器包括一个或多个EO晶体。 目标位于太赫兹脉冲的近场中的一个EO晶体上。

公开(公告)号：US06573700B2

公开(公告)日：2003-06-03

申请号：US10164454

申请日：2002-06-06

申请人： Xi-Cheng Zhang ,  Zhiping Jiang

发明人： Xi-Cheng Zhang ,  Zhiping Jiang

IPC分类号： G01R3100

CPC分类号： G01R29/0885

摘要： Characterization of free-space electromagnetic energy pulses (15) using a chirped optical probe beam is provided. An electro-optic or magneto-optic crystal (14) is positioned such that the free-space radiation and chirped optical probe signal co-propagate, preferably in a co-linear common direction, through the crystal where a temporal waveform of the free-space radiation is linearly encoded onto a wavelength spectrum of the chirped optical probe signal. The temporal waveform of the free-space radiation is then reconstructed using, for example, a dynamic subtraction of the spectral distribution of the chirped optical probe signal without modulation from the spectral distribution of the chirped optical probe signal with modulation by the free-space radiation.

公开(公告)号：US5952818A

公开(公告)日：1999-09-14

申请号：US739099

申请日：1996-10-25

申请人： Xi-Cheng Zhang ,  Louis Francis Libelo ,  Qi Wu

发明人： Xi-Cheng Zhang ,  Louis Francis Libelo ,  Qi Wu

IPC分类号： G01R29/08 ,  G01R31/00

CPC分类号： G01R29/0885

摘要： Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric field and a laser beam in an electro-optic crystal. In addition to a pratical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field--optical beam interaction length, thereby making imaging applications practical.

摘要翻译： 提出了表征自由空间电磁能的装置和方法，特别是适用于实时二维远红外成像应用的装置/方法。 感测技术基于电光晶体中低频电场与激光束之间的非线性耦合。 除了实际的反向传播感测技术之外，还描述了提供更长的辐射场 - 光束相互作用长度的共线方法，从而使成像应用成为实用的。

公开(公告)号：US5420595A

公开(公告)日：1995-05-30

申请号：US144724

申请日：1993-10-28

申请人： Xi-Cheng Zhang ,  David H. Auston

发明人： Xi-Cheng Zhang ,  David H. Auston

IPC分类号： H01Q3/26 ,  H01Q3/44 ,  H01Q3/22 ,  H01Q1/06 ,  H01Q3/24

CPC分类号： H01Q3/44 ,  H01Q3/2676

摘要： A source of collimated beam or beams of microwave electromagnetic radiation pulses comprises a photoconductor substrate having a major surface and an optical radiation source providing a beam of optical radiation pulses for illuminating at least a relatively large aperture region of the major surface. A static electric field, intrinsic or applied, is present at the major surface for driving transient photocurrents generated by the beam of optical radiation pulses. Each beam of microwave electromagnetic radiation pulses emitted from the photoconductor substrate may be steered by varying the angle of incidence of the beam of optical radiation pulses illuminating the major surface, by varying the period of the spatial variation of a static electric field applied to the major surface by means of electrodes, or by varying the period or direction of a periodic intensity variation of a spatially modulated beam of optical radiation pulses on the major surface.

摘要翻译： 微波电磁辐射脉冲的准直光束或光束的源包括具有主表面的光电导体基底和提供用于照射主表面的至少相对大的开口区域的光辐射脉冲束的光辐射源。 固有或应用的静电场存在于主表面上，用于驱动由光辐射脉冲束产生的瞬态光电流。 通过改变施加到主表面的静电场的空间变化的周期，可以通过改变照射主表面的光辐射脉冲束的入射角来控制从感光体基板发射的每束微波电磁辐射脉冲 或通过改变在主表面上的空间调制光束的光辐射脉冲的周期性强度变化的周期或方向。

公开(公告)号：US08796653B2

公开(公告)日：2014-08-05

申请号：US12886131

申请日：2010-09-20

申请人： Brian Schulkin ,  Xi-Cheng Zhang ,  Thomas Tongue ,  Jingzhou Xu ,  Jian Chen

发明人： Brian Schulkin ,  Xi-Cheng Zhang ,  Thomas Tongue ,  Jingzhou Xu ,  Jian Chen

IPC分类号： H01J29/02 ,  H01S5/022

CPC分类号： G21K5/00 ,  B33Y80/00 ,  G01J4/00 ,  G01N21/211 ,  G01N21/3581 ,  H01S5/02236 ,  H01S2302/02

摘要： Methods and apparatus for detecting variations in electromagnetic fields, in particular, terahertz (THz) electromagnetic fields, are provided. The methods and apparatus employ polarization detection devices and controllers to maintain or vary the polarization of modulated signals as desired. The methods and apparatus are provided to characterize electromagnetic fields by directing the electromagnetic field and a probe beam upon an electro-crystal and detecting the modulation of the resulting probe beam. Detection of the modulation of the probe beam is practiced by detecting and comparing the polarization components of the modulated probe beam. Aspects of the invention may be used to analyze or detect explosives, explosive related compounds, and pharmaceuticals, among other substances. A compact apparatus, modular optical devices for use with the apparatus, sample holders, and radiation source mounts are also disclosed.

摘要翻译： 提供了用于检测电磁场，特别是太赫兹（THz）电磁场的变化的方法和装置。 所述方法和装置使用偏振检测装置和控制器来根据需要维持或改变调制信号的极化。 提供的方法和装置用于通过将电磁场和探针光束引导到电晶体上并检测所得到的探针光束的调制来表征电磁场。 通过检测和比较调制探测光束的偏振分量来实现探测光束的调制的检测。 本发明的方面可用于分析或检测爆炸物，爆炸性相关化合物和药物等物质。 还公开了一种紧凑的装置，用于装置，样品架和辐射源底座的模块化光学装置。

公开(公告)号：US20130153790A1

公开(公告)日：2013-06-20

申请号：US13643871

申请日：2011-04-29

申请人： Benjamin Clough ,  Jingle Liu ,  Xi-Cheng Zhang

发明人： Benjamin Clough ,  Jingle Liu ,  Xi-Cheng Zhang

IPC分类号： G01N21/63

CPC分类号： G01N21/63 ,  G01N21/3504 ,  G01N21/3581

摘要： Methods and systems for detecting radiation for example, terahertz radiation, with the aid of acoustic signal generation and detection include: directing an optical beam into a volume of gas; ionizing at least a portion of the volume of gas with the optical beam to produce a plasma; and detecting an acoustic signal produced from an interaction of a radiation wave with the plasma. The methods and systems are particularly adapted for remote detection of chemicals, biological substances, and explosives, among others. The capability of the methods and systems can be enhanced by employing multi-color laser excitation to produce the plasma and varying the time delay between the multi-color pulses.

摘要翻译： 借助于声信号产生和检测，用于检测辐射的方法和系统，例如太赫兹辐射，包括：将光束引导到一定体积的气体中; 用光束电离至少一部分体积的气体以产生等离子体; 以及检测由辐射波与等离子体的相互作用产生的声信号。 这些方法和系统特别适用于远程检测化学品，生物物质和爆炸物等。 可以通过采用多色激光激发产生等离子体并改变多色脉冲之间的时间延迟来增强方法和系统的能力。

公开(公告)号：US20120049090A1

公开(公告)日：2012-03-01

申请号：US13218993

申请日：2011-08-26

申请人： Xi-Cheng ZHANG ,  Pengyu HAN ,  Yuting W. CHEN

发明人： Xi-Cheng ZHANG ,  Pengyu HAN ,  Yuting W. CHEN

IPC分类号： B01J19/12 ,  G02B1/00 ,  B23P11/00 ,  G02B5/00

CPC分类号： G02B1/118 ,  Y10T29/49826

摘要： A terahertz (THz) anti-reflection device, for example, a broadband tunable THz anti-reflection device, includes a silicon substrate having a plurality of recesses, each of the plurality of recesses having a plurality of cavities of decreasing dimension. The cavities may be nested polygonal cavities, for example, having a square or rectangular cross section. The recesses having the cavities may be positioned at regular periods, for example, periods ranging from 10 μm to 20 μm. The devices may be fabricated by conventional lithographic methods. Also disclosed are methods for modifying terahertz radiation and methods for fabricating anti-reflection devices.

摘要翻译： 太赫兹（THz）抗反射装置，例如宽带可调THz抗反射装置，包括具有多个凹槽的硅基板，多个凹槽中的每一个具有多个尺寸减小的空腔。 空腔可以是嵌套的多边形空腔，例如具有正方形或矩形横截面。 具有空腔的凹部可以以规定的周期定位，例如10μm至20μm的周期。 这些器件可以通过常规的光刻方法制造。 还公开了用于修改太赫兹辐射的方法和用于制造防反射装置的方法。