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81.发明授权Polarization and wavelength stable superfluorescent sources using Faraday rotator mirrors 有权使用法拉第旋转镜的极化和波长稳定的超荧光源公开(公告)号：US06483628B1
公开(公告)日：2002-11-19
申请号：US09429044
申请日：1999-10-29
IPC分类号： H01S300
CPC分类号： H01S3/06795
摘要： The wavelength stability of superfluorescent sources is controlled with optical arrangements in which the polarization-dependent gain (PDG) induced by the polarized pump light is reduced. In one apparatus and method, a Faraday rotator mirror is used at the end of the waveguide in the superfluorescent source. In another apparatus and method, the birefringence of the waveguide is exploited in conjunction with a Faraday rotator mirror to further average out the effect of PDG on the mean wavelength difference between the spectral outputs of orthogonal polarization components.
摘要翻译： 超荧光源的波长稳定性由偏振泵浦光引起的偏振相关增益（PDG）减小的光学配置来控制。 在一种装置和方法中，在超荧光源中在波导的末端使用法拉第旋转镜。 在另一种装置和方法中，波导的双折射与法拉第旋转镜结合使用，以进一步平衡PDG对正交偏振分量的光谱输出之间的平均波长差的影响。
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公开(公告)号：US06466364B1
公开(公告)日：2002-10-15
申请号：US10060868
申请日：2002-01-29
IPC分类号： H01S300
CPC分类号： H04B10/294 , G02F1/3519 , H01S3/06754 , H01S3/1302 , H01S2301/04 , H01S2301/06 , H04B10/2935
摘要： An apparatus and a method provide gain flattening in communications systems wherein a large number of optical signals at different wavelengths must be amplified while maintaining signal power within an acceptable range. Because of differences in gain of typical optical amplifiers as a function of wavelength and input power, the signals at different wavelengths are not amplified by the same amounts. Thus, when amplified multiple times, certain signals tend to become severely attenuated to the point of being no longer useable. The present gain flattening apparatus and method cause signals having higher gain-power products to be attenuated by a greater amount in response to Kerr-induced phase shifting such that after multiple stages of amplification, all the signal powers converge toward a small range of acceptable output powers. The apparatus provides amplification, multiple times, of a series of signals with a plurality of wavelengths covering a very wide spectral range, while maintaining the power of all the signals within a small range. The spread of this signal power range is robust against changes in the signal power, against changes in the number of signals, and, to some degree, against changes in the amplifier's pump power. The apparatus design is also robust against manufacturing changes in the parameters of the apparatus' components. The apparatus and invention are preferably implemented as multiple nonlinear Sagnac amplifiers having erbium-doped fiber amplifiers positioned asymmetrically in an interferometer loop.
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公开(公告)号：US06385354B1
公开(公告)日：2002-05-07
申请号：US09259832
申请日：1999-03-01
申请人： Michel J. F. Digonnet , Alice Liu , Gordon S. Kino
发明人： Michel J. F. Digonnet , Alice Liu , Gordon S. Kino
IPC分类号： G02F101
CPC分类号： G02F1/0134 , G02F1/3136
摘要： An apparatus modulates the phase of an optical signal. The apparatus includes an optical medium for propagating the optical signal. At least one electrode is positioned in proximity with the medium. The electrode induces an electric field within the medium in response to an AC voltage to produce variations in the index of refraction of the optical medium through the electrostrictive effect. Preferably, the phase of the optical signal is modulated such that polarization components of the optical signal parallel to and orthogonal to the electric field experience an equal phase shift. In certain embodiments, a DC voltage is supplied to the optical medium. Alternatively, the DC voltage within the optical medium may arise from (or be enhanced by) poling the optical medium. Certain embodiments of the present invention include two electrodes positioned on opposite sides of the optical medium. The apparatus is advantageously used in an interferometer to form a device that modulates the amplitude of the optical signal. The apparatus may also be used in an interferometer to form an optical switching device.
摘要翻译： 一种装置调制光信号的相位。 该装置包括用于传播光信号的光学介质。 至少一个电极定位在介质附近。 电极响应于AC电压在介质内引起电场，以通过电致伸缩效应产生光学介质的折射率的变化。 优选地，调制光信号的相位，使得平行于和与电场正交的光信号的偏振分量经历相等的相移。 在某些实施例中，DC电压被提供给光学介质。 或者，光学介质内的DC电压可以由（或通过）光学介质极化而产生。 本发明的某些实施例包括位于光学介质的相对侧上的两个电极。 该装置有利地用于干涉仪中以形成调制光信号幅度的装置。 该装置还可用于干涉仪中以形成光开关装置。
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84.发明授权Tunable, mechanically induced long-period fiber grating with enhanced polarizing characteristics 有权可调谐，机械诱导具有增强的偏振特性的长周期光纤光栅公开(公告)号：US06282341B1
公开(公告)日：2001-08-28
申请号：US09469744
申请日：1999-12-21
IPC分类号： G02B634
CPC分类号： G02B6/02071 , G02B6/02095 , G02B6/02109 , G02B6/022 , G02B6/274 , G02B6/2793 , H01S3/0675 , H01S2301/04
摘要： A new type of fiber filter is useable in optical communication systems. In particular, the fiber filter may be used to flatten the gain of erbium-doped fiber amplifiers (EDFAs). Such gain flattening is important for long-haul, dense (wavelength dependent multiplexed) WDM communication systems. The filter includes a periodic mechanical structure pressed against the side of a single-mode fiber to induce a wavelength-dependent loss in a signal propagating in the fiber core by coupling the signal to fiber cladding modes. The mechanical structure is a periodic comb of small ridges. Each ridge induces a local index change in the fiber via the photoelastic effect. For coupling to the right cladding modes, the period of the grating (and the comb) is in the range of few hundreds of microns. Thus, the grating is easy to fabricate with standard machining equipment.
摘要翻译： 一种新型的光纤滤波器可用于光通信系统。 特别地，光纤滤波器可用于平坦化掺铒光纤放大器（EDFA）的增益。 这种增益平坦化对于长距离密集（波长相关多路复用）WDM通信系统是重要的。 滤波器包括按照单模光纤侧面的周期性机械结构，以通过将信号耦合到光纤包层模式来引起在光纤芯中传播的信号中的波长相关损耗。 机械结构是小脊的周期梳。 每个脊通过光弹效应引起纤维中的局部折射率变化。 为了耦合到正确的包层模式，光栅（和梳子）的周期在几百微米的范围内。 因此，光栅易于用标准的加工设备制造。
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公开(公告)号：US6160943A
公开(公告)日：2000-12-12
申请号：US64363
申请日：1998-04-22
CPC分类号： G02B6/262 , G02B6/02042 , G02B6/27 , G02B6/2804 , G02B6/2821 , G02B6/29332
摘要： An optical fiber has two or more cores with respective faces on the fiber's ends. The faces are preferably oriented so that optical radiation can be coupled into or out of the individual cores, thereby permitting, for example, optical radiation from the various cores to be spatially resolved in the far field. The faces can be formed on the fiber by polishing the fiber at an angle with respect to the cores, i.e., with respect to the optical paths traversed by the optical radiation passing through the fiber.
摘要翻译： 光纤具有两个或更多个芯，其纤维端部具有各自的面。 这些面优选地被定向成使得光辐射可以耦合到单独的芯中或从每个芯耦合，从而允许例如来自各种芯的光辐射在远场中被空间分辨。 可以通过相对于芯线以相对于通过光纤的光学辐射穿过的光路的方式抛光光纤而在光纤上形成面。
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公开(公告)号：US5311525A
公开(公告)日：1994-05-10
申请号：US861322
申请日：1992-03-31
CPC分类号： G02F1/365 , G02F1/3521 , H01S3/067 , H01S3/06783
摘要： An optical mode coupling apparatus includes an Erbium-doped optical waveguide in which an optical signal at a signal wavelength propagates in a first spatial propagation mode and a second spatial propagation mode of the waveguide. The optical signal propagating in the waveguide has a beat length. The coupling apparatus includes a pump source of perturbational light signal at a perturbational wavelength that propagates in the waveguide in the first spatial propagation mode. The perturbational signal has a sufficient intensity distribution in the waveguide that it causes a perturbation of the effective refractive index of the first spatial propagation mode of the waveguide in accordance with the optical Kerr effect. The perturbation of the effective refractive index of the first spatial propagation mode of the optical waveguide causes a change in the differential phase delay in the optical signal propagating in the first and second spatial propagation modes. The change in the differential phase delay is detected as a change in the intensity distribution between two lobes of the optical intensity distribution pattern of an output signal. The perturbational light signal can be selectively enabled and disabled to selectively change the intensity distribution in the two lobes of the optical intensity distribution pattern.
摘要翻译： 光模耦合装置包括铒掺杂光波导，其中信号波长的光信号以波导的第一空间传播模式和第二空间传播模式传播。 在波导中传播的光信号具有拍子长度。 耦合装置包括在扰动波长处的扰动光信号的泵浦源，其在第一空间传播模式中在波导中传播。 扰动信号在波导中具有足够的强度分布，其根据光学克尔效应引起波导的第一空间传播模式的有效折射率的扰动。 光波导的第一空间传播模式的有效折射率的扰动导致在第一和第二空间传播模式中传播的光信号中的差分相位延迟的变化。 差分相位延迟的变化被检测为输出信号的光强度分布图案的两个波瓣之间的强度分布的变化。 扰动光信号可以选择性地启用和禁用，以选择性地改变光强度分布图案的两个波瓣中的强度分布。
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公开(公告)号：US5048026A
公开(公告)日：1991-09-10
申请号：US191770
申请日：1988-05-04
IPC分类号： H01S3/067 , H01S3/094 , H01S3/0941
CPC分类号： H01S3/0941 , H01S3/094003 , H01S3/06745 , H01S3/094007 , H01S3/094019 , H01S3/094069
摘要： A side pumped, fiber optic amplifier comprises an optical fiber, having a first refractive index, formed of a laser material, such as Nd:YAG. A jacket, which surrounds the optical fiber, has a second refractive index, lower than the first refractive index. This jacket is cone shaped and tapers from a large end to a small end. High power laser diodes are mounted on the large end to introduce pump light to pump the optical fiber material. The cone-shaped jacket focuses this pump light to an interaction region at the small end, where the jacket material is quite thin, e.g. on the same order of magnitude as the diameter of the optical fiber. The focused light is absorbed by the optical fiber in this interaction region, and causes an electronic population inversion in the laser fiber material. A signal propagating through the optical fiber stimulates spontaneous emission from the optically excited laser material, thereby resulting in amplification of the signal.
摘要翻译： 侧泵浦的光纤放大器包括具有第一折射率的光纤，由诸如Nd：YAG的激光材料形成。 围绕光纤的护套具有比第一折射率低的第二折射率。 这件夹克是锥形的，从大端到小端渐缩。 大功率激光二极管安装在大端，引入泵浦光来泵浦光纤材料。 锥形护套将该泵浦光聚焦到小端的相互作用区域，其中护套材料相当薄，例如， 与光纤的直径相同的数量级。 聚焦光在该相互作用区域被光纤吸收，并导致激光纤维材料中的电子群体反转。 通过光纤传播的信号刺激光激发激光材料的自发发射，从而导致信号的放大。
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公开(公告)号：US4738503A
公开(公告)日：1988-04-19
申请号：US828782
申请日：1986-02-12
CPC分类号： G02B6/24 , G02B6/2821 , G02B6/2861 , G11C21/00 , H01S3/0057 , H01S3/302 , G02F2203/54 , H01S2301/08 , Y10S359/90
摘要： A fiber optic recirculating memory comprises a splice-free length of optical fiber which forms a loop that is optically closed by means of a fiber optic coupler. The coupler couples an optical signal input pulse to the loop for circulation therein, and outputs a portion of the signal pulse on each circulation to provide a series of output pulses. A pump source is included to pump the fiber loop with a pump signal having sufficient intensity to cause stimulated Raman scattering in the fiber loop, and thereby cause amplification of the circulating signal pulse. The fiber characteristics, coupler characteristics, and a pump power are selected to yield a Raman gain which compensates for the total round-trip losses in the fiber loop, so as to provide an output pulse train of constant amplitude pulses. The invention may be implemented utilizing a standard coupler with a pump signal modulation technique. The pump signal is input to the loop as a series of pulses having a duration and a periodicity chosen to prevent overlap of recirculating pump pulses with input pump pulses until at least two circulations of the loop, which minimizes pump power fluctuations and will therefore enhance output signal stability.
摘要翻译： 光纤再循环存储器包括无接头长度的光纤，其形成通过光纤耦合器光闭合的环路。 耦合器将光信号输入脉冲耦合到环路以在其中循环，并且在每个循环上输出信号脉冲的一部分以提供一系列输出脉冲。 包括泵浦源以用具有足够强度的泵浦信号泵送光纤环，以在光纤回路中引起受激拉曼散射，从而引起循环信号脉冲的放大。 选择光纤特性，耦合器特性和泵浦功率以产生拉曼增益，其补偿光纤环路中的总往返损耗，从而提供恒定幅度脉冲的输出脉冲串。 本发明可以利用具有泵浦信号调制技术的标准耦合器来实现。 泵浦信号作为一系列具有持续时间和周期性的脉冲输入到循环中，以防止循环泵浦脉冲与输入泵浦脉冲的重叠，直到循环的至少两个循环，这最小化泵浦功率波动并且因此将增强输出 信号稳定。
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公开(公告)号：US4556279A
公开(公告)日：1985-12-03
申请号：US319301
申请日：1981-11-09
CPC分类号： G02B6/29332 , G02B6/2826 , G02B6/283 , G02B6/2938 , G02B6/29395
摘要： A passive, frequency selective, fiber optic multiplexer, comprises a directional coupler in which a pair of single mode optical fibers are accurately positioned to provide evanescent field coupling, typically by polishing a portion of the cladding from each of said fibers to place the respective cores of said fibers within the evanescent field of light in the other fiber. The coupling efficiency of a coupler constructed in this manner is wavelength dependent, and provides over-coupling, that is, the capability of transferring light, virtually entirely, back and forth between the fibers within the coupler. The wavelength dependent nature of the evanescent field coupling permits multiplexing, specifically between a pair of wavelengths, one of which is coupled in its entirety from a first fiber to a second fiber, and the other of which is essentially uncoupled. By increasing the number of total transfers of the light signals between the pair of fibers, the frequency resolution of the multiplexer may be optimized for light signals of virtually any frequency separation.
摘要翻译： 无源频率选择性光纤多路复用器包括定向耦合器，其中一对单模光纤被精确地定位以提供渐逝场耦合，通常通过从每个所述光纤抛光一部分包层以放置相应的芯 的纤维在另一纤维中的消逝光场内。 以这种方式构造的耦合器的耦合效率是波长相关的，并且提供过耦合，即在耦合器内的光纤之间实际上完全传输光的能力。 消逝场耦合的波长依赖性允许多路复用，特别是在一对波长之间进行多路复用，其中一个波长的整体由第一光纤耦合到第二光纤，另一个基本上是耦合的。 通过增加一对光纤之间的光信号的总传输次数，多路复用器的频率分辨率可以针对几乎任何频率间隔的光信号进行优化。
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公开(公告)号：US4553238A
公开(公告)日：1985-11-12
申请号：US537493
申请日：1983-09-30
IPC分类号： G02B6/00 , G02B6/28 , G02B6/287 , G02F1/35 , H01S3/06 , H01S3/07 , H01S3/091 , H01S3/0915 , H01S3/094 , H01S3/30
CPC分类号： H01S3/094003 , H01S3/094011 , H01S3/094019 , H01S3/094069
摘要： A pair of small diameter optical fibers are arranged in a side-by-side configuration, the first fiber providing a passive guide for pump light, and the second fiber formed of a material, such as Nd:YAG which has amplifying properties at the signal frequency. The signal to be amplified propagates through the second fiber from the active material, resulting in amplification of the signal. The first fiber is pumped from one or both ends, utilizing a cone shaped rod which is optically coupled thereto. A large diameter beam of collimated pump light enters the cone shaped rod, where total internal reflections on the cone walls compress the beam to a small, fiber-size diameter for absorption by the active fiber. The light input to the cone-shaped rod is produced by plural, high power laser diodes, and is collimated by microlenses. By utilizing the cone-shaped rod to couple light from the high power diode lasers to the pump fiber, high pump power densities can be achieved, yielding increased amplification.
摘要翻译： 一对小直径光纤配置成并排配置，第一光纤提供泵浦光的被动导向器，第二光纤由诸如Nd：YAG的材料形成，该材料在信号处具有放大特性 频率。 要被放大的信号通过第二光纤从活性材料传播，导致信号的放大。 第一纤维从一端或两端泵送，利用光学耦合到其上的锥形杆。 准直泵浦光的大直径光束进入锥形棒，锥形壁上的全部内部反射将光束压缩至较小的纤维尺寸直径，以被有源光纤吸收。 输入到锥形杆的光由多个高功率激光二极管产生，并被微透镜准直。 通过利用锥形杆将来自大功率二极管激光器的光耦合到泵浦光纤，可以实现高泵功率密度，产生增加的放大。
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