Carrier-suppressed optical time domain multiplexing
    2.
    发明授权
    Carrier-suppressed optical time domain multiplexing 有权
    载波抑制光时域复用

    公开(公告)号:US07574139B2

    公开(公告)日:2009-08-11

    申请号:US10157900

    申请日:2002-05-31

    IPC分类号: H04J14/08

    CPC分类号: H04J14/08

    摘要: A method and an apparatus for implementing carrier suppressed data format on conventional OTDM modules is provided. Adaptive phase shifting of optical signals traversing one of the tributaries of an OTDM module is performed with feedback loop control. A tapped portion of the input carrier signal is phase modulated at a frequency fc, and is combined with a tapped portion of the output from the OTDM. A phase shifter controller fed with this combined signal photodetects and band-pass filters the signal around fc to extract the amplitude of the AC component of the envelope of the combined signal, which depends upon the phase difference between successive pulses of the OTDM output. This signal is used to control a phase shifter coupled along one of the tributaries of the OTDM to adjust the phase difference of the signals of the two tributaries so that carrier suppression results.

    摘要翻译: 提供了一种用于在常规OTDM模块上实现载波抑制数据格式的方法和装置。 通过反馈回路控制执行穿过OTDM模块支路之一的光信号的自适应相移。 输入载波信号的抽头部分以频率fc相位调制,并与OTDM的输出的抽头部分组合。 馈送该组合信号的移相器控制器对fc周围的信号进行光谱检测和带通滤波,以提取组合信号的包络的AC分量的幅度,这取决于OTDM输出的连续脉冲之间的相位差。 该信号用于控制沿着OTDM的一个支路耦合的移相器,以调整两个支路的信号的相位差,从而导致载波抑制。

    Optical circuits for tunable second order PMD compensation and tunable dispersion compensation

    公开(公告)号:US07027135B2

    公开(公告)日:2006-04-11

    申请号:US10157901

    申请日:2002-05-31

    IPC分类号: G01N21/00

    摘要: A method and an apparatus is provided for introducing tunable second order polarization mode dispersion compensation to an optical signal without introducing any first order polarization mode dispersion into the optical signal. A method and an apparatus is also provided for tunable chromatic dispersion compensation by rotating the polarization state of an input signal to match the chromatic like second order PMD compensation provided by the present invention. In one configuration, birefringent elements are arranged into at least two stages, each stage having at least two birefringent elements, each birefringent element of one stage oriented orthogonal to a corresponding birefringent element of a corresponding stage. In another configuration, the polarization of optical signals emerging from each birefringent element are rotated to create effective orthogonal orientations between corresponding birefringent elements of corresponding stages.

    Fingerprint template based on fuzzy feature point information and fingerprint identification method

    公开(公告)号:US09886619B2

    公开(公告)日:2018-02-06

    申请号:US14902288

    申请日:2014-12-24

    申请人: Feng Shi

    IPC分类号: G06K9/00

    摘要: The present invention discloses a fingerprint template and a fingerprint identification method based on fuzzy feature point information. The fingerprint template contains several pieces of incomplete feature point information, including registration information and comparison information, wherein only coordinate information and attribute information of feature points and a value of a polynomial are recorded. In the polynomial P(Xi)=C0+C1Xi+C2Xi2 . . . CnXin, n is an order of the polynomial, and Xi is a numerical value obtained by quantifying one or multiple pieces of feature point information except the registration information in the feature point information and is a coefficient having a certain preset rule. Corresponding feature point information of a scene fingerprint is substituted into the polynomial to figure out C0-Cn, and whether the C0-Cn meet the preset rule is judged to judge whether the scene fingerprint is matched with a template fingerprint.