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    Optical Voltage Controlled Oscillator for an Optical Phase Locked Loop
    3.
    发明申请
    Optical Voltage Controlled Oscillator for an Optical Phase Locked Loop 审中-公开
    光锁相环的光电压控振荡器

    公开(公告)号：US20080292326A1

    公开(公告)日：2008-11-27

    申请号：US11630178

    申请日：2004-09-15

    Applicant: Valter Ferrero ,  Roberto Gaudino

    Inventor： Valter Ferrero ,  Roberto Gaudino

    IPC: H04B10/148

    CPC classification number: H04B10/60

    Abstract: An optical phase locked loop (1), comprising an optical phase detector (2) receiving as inputs an optical signal to be locked (symbol I) and a locked optical signal (symbol II) and providing as its output an electrical error signal (VPD) indicating the phase shift existing between the optical signal to be locked (symbol I) and the locked optical signal (symbol II); an electrical loop filter (3) receiving the electrical error signal (VPD) and outputting a filtered electrical error signal (VPDF), and an optical voltage controlled oscillator (4) receiving as an input the filtered electrical error signal (VPDF) and outputting the locked optical signal (symbol II). The optical voltage controlled oscillator (4) comprises an electrical voltage controlled oscillator (8) receiving as an input the filtered electrical error signal (VPDF) and outputting a modulating electrical signal (VEVCO), an external-cavity semiconductor laser source (9) providing an optical carrier (SOC), and a Mach-Zehnder optical amplitude modulator (10) receiving as an input the optical carrier (SOC) and the modulating electrical signal (VEVCO) and outputting the locked optical signal (symbol II), which is obtained by amplitude modulating the optical carrier (SOC) with the modulating electrical signal (VEVCO).

    Abstract translation: 一种光锁相环（1），包括光相位检测器（2），接收要锁定的光信号（符号I）和锁定光信号（符号II）作为输入，并提供电误差信号（VPD ）表示存在于待锁定的光信号（符号I）和锁定的光信号（符号II）之间的相移; 接收电差错信号（VPD）并输出滤波电误差信号（VPDF）的电路环路滤波器（3）和接收经滤波的电差错信号（VPDF）作为输入的光压控振荡器， 锁定光信号（符号II）。 光压控振荡器（4）包括电压控制振荡器（8），其接收经过滤波的电误差信号（VPDF）作为输入，并输出调制电信号（VEVCO）;外腔半导体激光源（9），提供 光学载体（SOC）和马赫 - 策德尔光学幅度调制器（10），其接收作为输入的光载波（SOC）和调制电信号（VEVCO），并输出锁定的光信号（符号II），其被获得 通过用调制电信号（VEVCO）对光载波（SOC）进行幅度调制。

    Automatic gain control for free-space optical telecommunications links
    5.
    发明授权
    Automatic gain control for free-space optical telecommunications links 失效
    自由空间光通信链路的自动增益控制

    公开(公告)号：US6031648A

    公开(公告)日：2000-02-29

    申请号：US847072

    申请日：1997-05-01

    Applicant: Joel I. Javitt ,  Christopher L. Rutledge

    Inventor： Joel I. Javitt ,  Christopher L. Rutledge

    IPC: H04B10/02 ,  H04B10/10 ,  H04B10/105 ,  H04B10/148 ,  H04B10/18 ,  H04B10/22 ,  H04B10/00

    CPC classification number: H04B10/60

    Abstract: Free-space optical transmission of analog information is facilitated by transmitting constant-amplitude pilot information with the other information. The amount of attenuation of the pilot information at the receiver is detected and used to control the amount by which received information is amplified. In this way the deleterious effects of free-space optical attenuation are substantially eliminated. The pilot information may be transmitted either via its own separate light frequency or wavelength, or as a distinguishable part of a larger quantity of information that is used to modulate one light frequency or wavelength.

    Abstract translation: 通过将恒定幅度导频信息与其他信息进行传输，便于模拟信息的自由空间光传输。 检测接收机导频信息的衰减量，并用于控制接收信息被放大的量。 以这种方式，基本上消除了自由空间光衰减的有害影响。 导频信息可以经由其单独的光频率或波长或作为用于调制一个光频率或波长的较大量的信息的可区分部分来传输。

    Low-bias heterodyne fiber-optic communication link
    6.
    发明授权
    Low-bias heterodyne fiber-optic communication link 失效
    低偏差外差光纤通信链路

    公开(公告)号：US5526158A

    公开(公告)日：1996-06-11

    申请号：US334839

    申请日：1994-12-22

    Applicant: Lawrence J. Lembo

    Inventor： Lawrence J. Lembo

    IPC: H04B10/04 ,  H04B10/02 ,  H04B10/06 ,  H04B10/142 ,  H04B10/152 ,  H04B10/18 ,  H04B10/148

    CPC classification number: H04B10/64 ,  H04B10/588

    Abstract: An optical communication link having an overall linear transfer characteristic and high dynamic range suitable for transmitting analog signals. The link includes an optical intensity modulator, such as a Mach-Zehnder modulator, biased to a low-bias point to reduce noise, and a detector that performs optical heterodyning to recover a transmitted modulating signal. Heterodyning produces a beat frequency signal and sidebands that contain the same information as the modulating signal, but without second-harmonic distortion components. Use of the low-bias point is known to reduce noise and increase dynamic range, but only at the expense of second-harmonic distortion because the modulator output is a function of the square of the modulating signal. Although second harmonics can be filtered out, the bandwidth of the modulating signal is then limited to less than an octave. In the communication link of the invention, heterodyning produces sidebands that vary with the square root of the modulator transmission characteristic. Therefore, the overall transfer characteristic is substantially linear, second harmonic distortion is eliminated, and the modulating signal can extend over a multi-octave bandwidth.

    Abstract translation: 具有适于传输模拟信号的总线性传输特性和高动态范围的光通信链路。 链路包括诸如马赫 - 曾德尔调制器的光强度调制器，偏置到低偏置点以降低噪声;以及检测器，其执行光学外差以恢复传输的调制信号。 异步产生拍频信号和边带，其包含与调制信号相同的信息，但没有二次谐波失真分量。 已知低偏置点的使用可以降低噪声并增加动态范围，但只能以二次谐波失真为代价，因为调制器输出是调制信号的平方的函数。 尽管可以滤除二次谐波，然后将调制信号的带宽限制为小于八度。 在本发明的通信链路中，外差产生随着调制器传输特性的平方根而变化的边带。 因此，整体传输特性基本上是线性的，二次谐波失真被消除，并且调制信号可以在多倍频程带宽上延伸。

    Device for optical heterodyne detection and mirror system suitable for use in such a device
    7.
    发明授权
    Device for optical heterodyne detection and mirror system suitable for use in such a device 失效
    用于光学外差检测的装置和适用于这种装置的镜子系统

    公开(公告)号：US5237442A

    公开(公告)日：1993-08-17

    申请号：US882747

    申请日：1992-05-11

    Applicant: Giok D. Khoe ,  Kieran G. Wright

    Inventor： Giok D. Khoe ,  Kieran G. Wright

    IPC: H04B10/148

    CPC classification number: H04B10/61 ,  H04B10/614 ,  H04B10/63 ,  H04B10/64

    Abstract: In an optical heterodyne or homodyne receiver an optical system (140) is used in which the local oscillator beam (L) is combined with the signal beam (S). Simultaneously, these beams are split into orthogonally polarized sub-beams. For this purpose the optical system (140) comprises polarization-sensitive beam-splitting layers (141a and 141b) and neutral beam-splitting layers (142a and 142b) which function as beam-combining elements. In order to align the directions of the exit sub-beams of the signal beam (.sub.11, S.sub.12, S.sub.2, S.sub.22) and the local oscillator beam (L.sub.11, L.sub.12, L.sub.21, L.sub.22), the angles (.alpha., .beta., .gamma., .delta.) enclosed by the beam-splitting faces are chosen to be such that two angles located opposite each other have a combined magnitude of 180.degree.. This is realised by providing the layers (141a, 142b and 141b, 142a) on side faces of one prism (140a, 140b).

    Abstract translation: 在光学外差或零差接收机中，使用光学系统（140），其中本地振荡器波束（L）与信号波束（S）组合。 同时，这些光束被分成正交极化的子光束。 为此，光学系统（140）包括用作束组合元件的偏振敏感光束分离层（141a和141b）和中性光束分离层（142a和142b）。 为了使信号光束（11，S12，S2，S22）和本地振荡器光束（L11，L12，L21，L22）的退出子光束的方向对齐，角度（α，β，γ， ）被选择为使得彼此相对定位的两个角度具有180度的组合大小。 这通过在一个棱镜（140a，140b）的侧面上设置层（141a，142b和141b，142a）来实现。

    Double-stage phase-diversity receiver
    8.
    发明授权
    Double-stage phase-diversity receiver 失效
    双级相位分集接收机

    公开(公告)号：US5146359A

    公开(公告)日：1992-09-08

    申请号：US759036

    申请日：1991-09-05

    Applicant: Takanori Okoshi ,  Shinji Yamashita

    Inventor： Takanori Okoshi ,  Shinji Yamashita

    IPC: H04B10/148

    CPC classification number: H04B10/61 ,  H04B10/613 ,  H04B10/63 ,  H04B10/64

    Abstract: A double-stage phase-diversity receiver divides one signal into a plurality of signals. These divided signals are mixed with first-stage local oscillation signals having predetermined phase relations to thereby provide a plurality of electrical baseband signals. These electrical signals are up-converted by using second-stage local oscillation signals having a predetermined phase relation. The up-converted IF signals are added, and are then demodulated by a heterodyne scheme.

    Abstract translation: 双级相位分集接收器将一个信号分成多个信号。 这些分频信号与具有预定相位关系的第一级本地振荡信号混合，从而提供多个电基带信号。 这些电信号通过使用具有预定相位关系的第二级本地振荡信号进行上变频。 加上变换的IF信号，然后通过外差方案进行解调。

    Mixing interferometer used as a communications link
    9.
    发明授权
    Mixing interferometer used as a communications link 失效
    混合干涉仪用作通信链路

    公开(公告)号：US5144468A

    公开(公告)日：1992-09-01

    申请号：US367395

    申请日：1989-06-16

    Applicant: Robert T. Weverka

    Inventor： Robert T. Weverka

    IPC: H04B10/148

    CPC classification number: H04B10/61 ,  H04B10/614 ,  H04B10/64

    Abstract: An interferometer, such as a fiberoptic Mach-Zehnder type, is equipped at a transmission end of the system with a phase modulator driven by a data-input signal to be transmitted; and at a reception end with another phase modulator driven by a large reference signal. Nonlinear dependence of output intensity on these signals yields an intensity component that is the product of the signals at the modulators; and in turn an electrical output-signal component at frequency equal to the difference between the data- and reference-signal frequencies. A servocontrolled phase bias holds the system near a minimum in overall light level, where nonlinearity is prominent while intensity-related noise is minimized. The reference source and the bias are at the receiver end of the system, providing advantages: (1) the reference signal can be tuned manually or dynamically to optimize reproduction of the input signal, (2) the detector output can be mixed back up to the original data-input frequency using the same reference for mixing up as used optically for mixing down--eliminating frequency error and drift, and excess phase noise; and (3) only the modulators and purely optical elements need operate near the data frequency, which may be very high, while the detector and its amplifier run at the difference frequency.

    Abstract translation: 在系统的发送端配备有诸如光纤Mach-Zehnder型干涉仪，其相位调制器由要传输的数据输入信号驱动; 并且在接收端具有由大的参考信号驱动的另一个相位调制器。 输出强度对这些信号的非线性依赖性产生作为调制器信号的乘积的强度分量; 并且进而在频率等于数据和参考信号频率之间的电输出信号分量。 伺服控制的相位偏置使系统接近整体光线水平的最小值，其中非线性突出，而强度相关噪声最小化。 参考源和偏置位于系统的接收端，提供了以下优点：（1）可以手动或动态调整参考信号以优化输入信号的再生，（2）检测器输出可以混合回 原始数据输入频率使用相同的参考用于混合使用，用于混合下消除频率误差和漂移，以及多余相位噪声; 和（3）只有调制器和纯光学元件需要在数据频率附近工作，这可能非常高，而检测器及其放大器以差频运行。

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