Devices and methods for reducing dispersion in optical communications
    1.
    发明授权
    Devices and methods for reducing dispersion in optical communications 失效
    用于减少光通信中色散的设备和方法

    公开(公告)号:US06546170B1

    公开(公告)日:2003-04-08

    申请号:US09799089

    申请日:2001-03-06

    IPC分类号: G02B642

    摘要: Asymmetric grating assisted couplers present unique problems if dispersion is to be reduced to levels at which high data rate signals can be transmitted. To overcome these problems, the method of the present invention includes precisely controlling and monitoring the cross-sectional geometry of the coupler during stretching and fusing. By monitoring states of polarization in lowest order modes as the coupler is formed, coupler fusion can be terminated when optimum form birefringence minimizing PMD is achieved. Dispersion is further minimized by impressing a saturated index of refraction grating with substantially flat add/drop characteristics in the coupler, and introducing a controlled amount of twist.

    摘要翻译: 如果将色散降低到可以传输高数据速率信号的电平,则非对称光栅辅助耦合器会带来独特的问题。 为了克服这些问题,本发明的方法包括在拉伸和熔化期间精确地控制和监视耦合器的横截面几何形状。 通过在形成耦合器时监测最低阶模式的极化状态,当实现最小化PMD的最佳形式双折射时,可以终止耦合器熔合。 通过在耦合器中施加具有基本平坦的加/减特性的饱和折射率光栅,并且引入受控量的扭曲,进一步使色散最小化。

    Wavelength selective optical couplers
    4.
    发明授权
    Wavelength selective optical couplers 失效
    波长选择光耦合器

    公开(公告)号:US06289699B1

    公开(公告)日:2001-09-18

    申请号:US09035919

    申请日:1998-03-06

    IPC分类号: C03B3715

    摘要: A wavelength selective optical fiber coupler having various applications in the field of optical communications is disclosed. The coupler is composed of dissimilar waveguides in close proximity. A light induced, permanent index of refraction grating is recorded in the coupler waist The grating filters and transfers energy within a particular range of wavelengths from a first waveguide to a second waveguide. Transversely asymmetric gratings provide an efficient means of energy transfer. The coupler can be used to combine or multiplex a plurality of lasers operating at slightly different wavelengths into a single fiber. Other embodiments such as a dispersion compensator and gain flattening filter are disclosed.

    摘要翻译: 公开了一种在光通信领域具有各种应用的波长选择性光纤耦合器。 耦合器由相邻的不同波导组成。 光诱导的永久折射率光栅被记录在耦合器腰部中。光栅在从第一波导到第二波导的特定波长范围内过滤和传递能量。 横向不对称光栅提供了有效的能量传递手段。 耦合器可用于将以稍微不同的波长工作的多个激光器组合或多路复用到单个光纤中。 公开了诸如色散补偿器和增益平坦化滤光器的其它实施例。

    Methods of fabricating grating assisted coupler devices
    5.
    发明授权
    Methods of fabricating grating assisted coupler devices 失效
    制造光栅辅助耦合器件的方法

    公开(公告)号:US06169830A

    公开(公告)日:2001-01-02

    申请号:US09128476

    申请日:1998-08-04

    IPC分类号: G02B634

    摘要: Advantageous methodologies are disclosed for embedding periodic patterns in optical waveguide elements such as optical fibers. Polarization independence in an elongated waist region of an add/drop coupler can be established by measuring polarization characteristics during fusion and elongation, and controlling the elongation to impart a cross-sectional shape, such as a hybrid dumbbell-ellipsoid. Polarization dependence can also be minimized by angular deformation of the elements along the light transmissive axis. To write a pattern, an element having potential photosensitivity is markedly photosensitized in a hydrogen or deuterium environment pressurized to about 1000 to 5000 psi and a scanning UV beam that is transmitted through a photo mask and impinges on the coupler waist as the in-diffused gas is constantly replenished. Dimensional variations in the element which can affect spectral bandwidth are sensed by writing a preliminary test pattern in the element and then locally measuring the spectral properties of the test pattern and adjusting the local levels of background index of refractions so that the modal index of refraction is substantially constant along the length of the pattern. A relatively wide scanning writing beam tracks on a narrower waveguide element despite positional imprecision and temporal shifting by using a feedback signal derived from fluorescence induced in the element. To apodize the grating in accordance with a selected function, a constant power beam is directed through a rotating half-wave plate and divided by a polarizing beam splitter into two beams having oppositely varying DC amplitude characteristics. The two beams are separately varied to produce the desired apodization profile of the grating.

    摘要翻译: 公开了在诸如光纤的光波导元件中嵌入周期性图案的有利方法。 通过在熔融和伸长期间测量极化特性,并控制延伸率以赋予横截面形状,例如混合哑铃 - 椭圆体,可以建立加/减耦合器的细长腰部区域中的极化独立性。 也可以通过沿着透光轴的元件的角度变形来最小化极化依赖性。 为了编写图案,具有潜在光敏性的元件在加压至约1000至5000psi的氢或氘环境中被显着光敏化,并且扫描UV光束透射通过光掩模并且作为扩散气体撞击在耦合器的腰部上 不断补充。 通过在元素中写入初步测试图案然后局部测量测试图案的光谱特性并调整折射背景指数的局部水平,以便使模态折射率为 沿着图案的长度基本上恒定。 尽管通过使用从元件中诱导的荧光得到的反馈信号,位置不精确和时间偏移,相对宽的扫描写入光束在较窄的波导元件上轨迹。 为了根据所选择的功能使光栅变迹,恒定功率光束通过旋转半波片并被偏振分束器分成两束,具有相反变化的直流振幅特性。 两个光束分开变化,以产生光栅所需的变迹曲线。

    Fabrication of photosensitive strong grating couplers
    7.
    发明授权
    Fabrication of photosensitive strong grating couplers 失效
    感光强光栅耦合器的制造

    公开(公告)号:US06603903B1

    公开(公告)日:2003-08-05

    申请号:US09799090

    申请日:2001-03-06

    IPC分类号: G02B634

    CPC分类号: G02B6/02114

    摘要: Systems devices and methods in accordance with the invention impart high strength index of refraction patterns to photosensitive optical devices, such as Bragg gratings written in optical fibers. A length of small diameter fiber retaining photosensitivity is fabricated by flame elongation of an optical fiber precursor having dopant containing cladding, using a diffuse, low velocity inverted flame that does not introduce water, OH or H2 into the fiber. By varying the flame velocity during each scan the fiber is diminished to a small, uniform diameter, waist region. Photosensitivity is preserved and enhanced by exposure of the prepared waist region to scanning actinic illumination within an in-diffusing environment of pressurizing hydrogen or deuterium, and controlling the exposure to optimize the photo-induced index change. The photochemistry is balanced to provide a strong index of refraction grating by adjusting illumination instensity and scanning velocity to arrive at a low fraction of a selected photoabsorbing component of the dopant.

    摘要翻译: 根据本发明的系统装置和方法赋予光学光学装置(例如用光纤写入的布拉格光栅)的高强度折射率图。 通过使用不向水中引入水,OH或H 2的漫反射低速倒置火焰,通过具有含有掺杂剂的掺杂剂的光纤前体的火焰伸长来制造长度小的纤维保持光敏性。 通过在每次扫描期间改变火焰速度,纤维减小到一个小的,均匀的直径腰部区域。 通过将制备的腰围暴露于在加压氢或氘的扩散扩散环境内扫描光化照明并且控制曝光以优化光致指数变化来保持和增强光敏性。 光化学被平衡以通过调整照明强度和扫描速度来获得掺杂剂选择的光吸收组分的低分数来提供强折射率的光栅。

    Grating assisted coupler devices
    8.
    发明授权
    Grating assisted coupler devices 失效
    光栅辅助耦合器器件

    公开(公告)号:US06236782B1

    公开(公告)日:2001-05-22

    申请号:US09128477

    申请日:1998-08-04

    IPC分类号: G02B626

    摘要: An add/drop filter for optical wave energy incorporates a Bragg grating in a very narrow waist region defined by merged lengths of elongated optical fibers. Light is propagated into the waist region via adiabatically tapered fibers and is transformed from two longitudinally adjacent fibers into two orthogonal modes within the air-glass waveguide of the waist and reflected off the grating from one fiber into the other. The geometry of the waist region is such that the reflected drop wavelength is polarization independent, without lossy peaks in the wavelength band of interest. Additionally, back reflection are shifted out of the wavelength band of interest. High strength gratings are written by photosensitizing the waist region fibers by constantly in-diffusing pressurized hydrogen or deuterium. For narrow spectral bandwidth gratings, dimensional variations must be minimized or compensated, and the grating is apodized by both a.c. and d.c. variations in writing beams at a net constant power. A coupler device employing these precisely is arranged in a support structure which facilitates writing, testing and adjustment of gratings, and also provides temperature compensation and wavelength adjustment.

    摘要翻译: 用于光波能的加/减滤波器在由合并长度的细长光纤限定的非常窄的腰部区域中包含布拉格光栅。 光通过绝热的锥形纤维传播到腰部区域,并从两个纵向相邻的纤维转变成腰部的空气玻璃波导内的两个正交模式,并将其从光纤反射到另一个光纤。 腰部区域的几何形状使得反射的下降波长是偏振无关的,而在感兴趣的波长带中没有有损的峰值。 另外,反射反射被移出感兴趣的波长带外。 通过不断扩散加压氢或氘来对腰部区域纤维进行光敏化来写入高强度光栅。 对于窄光谱带宽光栅,尺寸变化必须最小化或补偿,并且光栅由a.c. 和d.c. 写入光束在净恒定功率下的变化。 使用这些精密的耦合器装置被布置在便于光栅的写入,测试和调整的支撑结构中,并且还提供温度补偿和波长调节。

    Grating assisted coupler devices
    10.
    发明授权
    Grating assisted coupler devices 失效
    光栅辅助耦合器器件

    公开(公告)号:US06578388B1

    公开(公告)日:2003-06-17

    申请号:US09721699

    申请日:2000-11-27

    IPC分类号: C03B3715

    摘要: An add/drop filter for optical wave energy incorporates a Bragg grating in a very narrow waist region defined by merged lengths of elongated optical fibers. Light is propagated into the waist region via adiabatically tapered fibers and is transformed from two longitudinally adjacent fibers into two orthogonal modes within the air-glass waveguide of the waist and reflected off the grating from one fiber into the other. The geometry of the waist region is such that the reflected drop wavelength is polarization independent, without lossy peaks in the wavelength band of interest. Additionally, back reflection are shifted out of the wavelength band of interest. High strength gratings are written by photosensitizing the waist region fibers by constantly in-diffusing pressurized hydrogen or deuterium. For narrow spectral bandwidth gratings, dimensional variations must be minimized or compensated, and the grating is apodized by both a.c. and d.c. variations in writing beams at a net constant power. A coupler device employing these precisely is arranged in a support structure which facilitates writing, testing and adjustment of gratings, and also provides temperature compensation and wavelength adjustment.

    摘要翻译: 用于光波能的加/减滤波器在由合并长度的细长光纤限定的非常窄的腰部区域中包含布拉格光栅。 光通过绝热的锥形纤维传播到腰部区域,并从两个纵向相邻的纤维转变成腰部的空气玻璃波导内的两个正交模式,并将其从光纤反射到另一个光纤。 腰部区域的几何形状使得反射的下降波长是偏振无关的,而在感兴趣的波长带中没有有损的峰值。 另外,反射反射被移出感兴趣的波长带外。 通过不断扩散加压氢或氘来对腰部区域纤维进行光敏化来写入高强度光栅。 对于窄光谱带宽光栅,尺寸变化必须最小化或补偿,并且光栅由a.c. 和d.c. 写入光束在净恒定功率下的变化。 使用这些精密的耦合器装置被布置在便于光栅的写入,测试和调整的支撑结构中,并且还提供温度补偿和波长调节。