公开(公告)号：US06429962B1

公开(公告)日：2002-08-06

申请号：US09730650

申请日：2000-12-05

申请人： Ming Xu ,  Tizhi Huang ,  Chongchang Mao ,  Jian-Yu Liu ,  Kuang-Yi Wu ,  Charles Wong

发明人： Ming Xu ,  Tizhi Huang ,  Chongchang Mao ,  Jian-Yu Liu ,  Kuang-Yi Wu ,  Charles Wong

IPC分类号： H04B1012

CPC分类号： H04B10/2941 ,  G02F1/0136 ,  G02F1/13471 ,  G02F2203/05 ,  G02F2203/48 ,  H01S3/06754 ,  H01S3/10023 ,  H01S2301/04

摘要： An optical equalizer for use primarily with an erbium-doped fiber amplifier has an initial polarizer that convert the input beam to a predetermined polarization, followed by a series of dynamically-adjustable sinusoidal filters that provide attenuation as a sinusoidal function of beam wavelength. Each of the sinusoidal filters has a first liquid crystal cell adjustably rotating the polarization of the beam from the preceding polarizer. This is followed by a second optical element that retards the beam as a sinusoidal function of beam wavelength. For example, the second optical element can be a birefringent crystal that provided a fixed degree of retardance to the beam and a second liquid crystal cell that provides a variable degree of retardance, thereby allowing adjustment of the center frequency of the sinusoidal function. Finally, a third liquid crystal cell adjustably rotates the polarization of the beam. A final polarizer provides amplitude control of the beam based on the polarization rotations introduced by the first and third liquid crystal cells. A controller provides control signals to the liquid crystal cells of each sinusoidal filter so that their combined sinusoidal attenuation functions produce a desired equalization curve.

摘要翻译： 主要用于掺铒光纤放大器的光学均衡器具有将输入光束转换为预定偏振的初始偏振器，随后是一系列动态可调的正弦滤波器，其提供作为波束波长的正弦函数的衰减。 每个正弦滤波器具有第一液晶单元，其可调节地使来自前一偏振器的光束的偏振旋转。 其后是第二光学元件，其将光束延迟为波束波长的正弦函数。 例如，第二光学元件可以是对光束提供固定的延迟度的双折射晶体和提供可变延迟的第二液晶单元，从而允许调整正弦函数的中心频率。 最后，第三液晶单元可调整地使光束的偏振旋转。 最终的偏振器基于由第一和第三液晶单元引入的偏振旋转来提供光束的幅度控制。 控制器向每个正弦滤波器的液晶单元提供控制信号，使得其组合的正弦衰减函数产生期望的均衡曲线。

公开(公告)号：US06519022B1

公开(公告)日：2003-02-11

申请号：US09621634

申请日：2000-07-21

申请人： Ming Xu ,  Chongchang Mao ,  Kuang-Yi Wu ,  Jian-Yu Liu

发明人： Ming Xu ,  Chongchang Mao ,  Kuang-Yi Wu ,  Jian-Yu Liu

IPC分类号： G02F113

CPC分类号： H04Q11/0005 ,  G02B6/272 ,  G02B6/2766 ,  G02F1/13471 ,  G02F1/31 ,  H04J14/0212 ,  H04Q2011/0024 ,  H04Q2011/0026 ,  H04Q2011/0035 ,  H04Q2011/0039 ,  H04Q2011/0052

摘要： An optical routing switch uses two liquid crystal cells that can produce offsetting rotations of the polarization of the input beam to provide fast, symmetrical switching. The input beam is first polarized and then passes through both liquid crystal cells in series. Both liquid crystal cells have two states (e.g., voltage-off and voltage-on) in which the beam polarization is rotated by predetermined angles (e.g., 0° and 90°), but in opposing rotational directions. A controller selectively rotates the LC cells through a sequence of steps, beginning with a “through” state in which both LC cells are in the first state. The polarization rotations provided by both liquid crystal cells offset one another so the beam polarization remains essentially unchanged. The LC cells can be rapidly switched to a “cross” state in which only one of the LC cells is changed to the second state and the polarization of the beam is rotated by a predetermined degree. The LC cells can then be rapidly switched back to the through state by changing both LC cells to their second state. Once again, the LC cells offset one another so that the beam polarization remains essentially unchanged. While remaining in the through state, both LC cells are allowed to return to the first state to complete the cycle. Both LC cells relax at the same rate and their offsetting polarization rotations cause the beam polarization to remain unchanged throughout the entire relaxation process. A polarization-dependent routing element (e.g., a polarized beamsplitter or birefringent element) routes the beam exiting the LC cells along either of two alternative optical paths based on the beam's polarization.

摘要翻译： 光路由开关使用两个液晶单元，其可以产生输入光束的偏振的偏移旋转，以提供快速，对称的切换。 输入光束首先被偏振，然后串联通过两个液晶单元。 两个液晶单元都具有其中光束偏振以预定角度（例如，0°和90°）旋转但在相反的旋转方向上的两种状态（例如，电压关闭和电压开启）。 控制器通过一系列步骤选择性地旋转LC单元，从两个LC单元处于第一状态的“通”状态开始。 由两个液晶单元提供的偏振旋转彼此偏移，使得光束偏振基本保持不变。 LC单元可以快速切换到“交叉”状态，其中仅一个LC单元被改变到第二状态，并且波束的偏振旋转预定的程度。 然后可以通过将两个LC单元改变到它们的第二个状态来将LC单元迅速地切换回到通过状态。 再次，LC单元彼此偏移，使得光束偏振基本保持不变。 当保持在通过状态时，允许两个LC单元返回到第一状态以完成循环。 两个LC单元以相同的速率松弛，并且它们的偏移偏振旋转导致光束偏振在整个弛豫过程中保持不变。 基于偏振相关的路由元件（例如，偏振分束器或双折射元件）基于光束的偏振来沿着两个备选光路中的任一个路由离开LC单元的光束。

公开(公告)号：US07034979B1

公开(公告)日：2006-04-25

申请号：US10290857

申请日：2002-11-08

申请人： Wei Feng ,  Chongchang Mao ,  Tirun Lin ,  Shuxin Li ,  Minchun Li ,  Ming Xu ,  Tizhi Huang

发明人： Wei Feng ,  Chongchang Mao ,  Tirun Lin ,  Shuxin Li ,  Minchun Li ,  Ming Xu ,  Tizhi Huang

IPC分类号： G02F1/03

CPC分类号： G02F1/1326 ,  G02F2201/34 ,  G02F2202/40 ,  G02F2203/48

摘要： An optical device for processing an optical signal includes a crystal wedge, a polarization modulator, and a reflective element. The crystal wedge spatially separates an input optical signal into a first beam component having a first polarization state and a second beam component having a second polarization state. The crystal wedge has an optical axis arranged at an optical axis angle such that the first beam component and the second beam component converge. The polarization modulator changes the polarization state of the first beam component and the polarization state of the second beam component in response to a control signal. The reflective element reflects the first beam component and the second beam component such that the crystal wedge spatially recombines a portion of the first beam component having the second polarization state with a portion of the second beam component having the first polarization state to form an output optical signal.

摘要翻译： 用于处理光信号的光学装置包括晶体楔，偏振调制器和反射元件。 晶体楔在空间上将输入光信号分离成具有第一偏振态的第一光束分量和具有第二偏振状态的第二光束分量。 晶体楔具有以光轴角度布置的光轴，使得第一光束分量和第二光束分量收敛。 响应于控制信号，偏振调制器改变第一光束分量的偏振状态和第二光束分量的偏振状态。 反射元件反射第一光束分量和第二光束分量，使得晶体楔将具有第二偏振状态的第一光束分量的一部分与具有第一偏振态的第二光束分量的一部分空间复合，以形成输出光学 信号。

公开(公告)号：US07023611B2

公开(公告)日：2006-04-04

申请号：US10077617

申请日：2002-02-15

申请人： Tizhi Huang ,  Ming Xu ,  Chongchang Mao ,  Tiejun Xia ,  Wei Feng

发明人： Tizhi Huang ,  Ming Xu ,  Chongchang Mao ,  Tiejun Xia ,  Wei Feng

IPC分类号： H04B10/12

CPC分类号： H04B10/2941 ,  H04B10/0731

摘要： Devices and methods for equalizing the gain of an optical amplifier are described. For devices including harmonic filters that are controllable by amplitude control voltages and phase control voltages, techniques for controlling the amplitude control voltages and phase control voltages are presented. Additionally, device architectures are described by which an incoming optical signal is equalized to compensate for uneven gain in prior amplifiers or other optical components, and in which the incoming optical signal is received at a beam displacer and separated into orthogonal component beams, wherein the beams are counter-propagated through the equalizer in opposite directions through the same spatial path so as to minimize or eliminate the effects spatially dependent imperfections in the equalizer.

公开(公告)号：US06972826B1

公开(公告)日：2005-12-06

申请号：US10098703

申请日：2002-03-14

申请人： Ming Xu ,  Chongchang Mao

发明人： Ming Xu ,  Chongchang Mao

IPC分类号： G02F1/13 ,  G02F1/133 ,  G02F1/31

CPC分类号： G02F1/13306 ,  G02F1/31

摘要： An optical processing device includes a polarization modulator operable to change a polarization state of an input optical signal based at least in part on a control voltage applied to a liquid crystal material associated with the polarization modulator. The control voltage is based at least in part on a temperature of the liquid crystal material.

摘要翻译： 光学处理装置包括至少部分地基于施加到与偏振调制器相关联的液晶材料的控制电压来改变输入光信号的偏振状态的偏振调制器。 控制电压至少部分地基于液晶材料的温度。

公开(公告)号：US5073010A

公开(公告)日：1991-12-17

申请号：US522609

申请日：1990-05-11

申请人： Kristina M. Johnson ,  Chongchang Mao ,  Ibrahim S. Abdulhalim

发明人： Kristina M. Johnson ,  Chongchang Mao ,  Ibrahim S. Abdulhalim

IPC分类号： G02F1/135

CPC分类号： G02F1/135

摘要： The disclosure describes an optically addressable spatial light modulator (OASLM) having a light sensitive member and a distorted helix ferroelectric liquid crystal (DHFLC). In a first embodiment a hydrogenated amorphous silicon (a-Si:H) photodiode layer is in physical contact with the DHFLC layer. In another embodiment an integrated circuit member includes a photosensitive area and an associated metal pad for each OASLM pixel, the metal pads in physical contact with corresponding DHFLC pixel areas. In the first embodiment, a low magnitude AC voltage (less than three to seven volts peak to peak) is connected to the OASLM as operating voltage, preferably in the absence of a DC offset voltage. The OASLM pixel areas of the OASLM are selectively addressed by a writing light wavefront, to thereby activate corresponding pixel areas of the light sensitive member. The voltage/current that is photogenerated in the activated pixels of the photosensitive member cause a current to flow, activating the corresponding DHFLC pixel areas. In an alternate construction of the first embodiment, the OASLM includes an external diode connected thereacross, this diode being operable to dissipate internal charge that may build up in the DHFLC. Reading of the activated DHFLC pixel areas of the DHFLC may be by way of a transmission or a reflection mode.

摘要翻译： 本发明描述了具有光敏元件和失真螺旋铁电液晶（DHFLC）的光寻址空间光调制器（OASLM）。 在第一实施例中，氢化非晶硅（a-Si：H）光电二极管层与DHFLC层物理接触。 在另一个实施例中，集成电路构件包括用于每个OASLM像素的光敏区域和相关联的金属焊盘，金属焊盘与对应的DHFLC像素区域物理接触。 在第一实施例中，优选地在没有DC偏移电压的情况下，将低幅度AC电压（小于3至7伏峰峰值）连接到OASLM作为工作电压。 OASLM的OASLM像素区域由写入光波阵面选择性地寻址，从而激活光敏元件的相应像素区域。 在光敏元件的激活像素中产生的电压/电流导致电流流动，激活相应的DHFLC像素区域。 在第一实施例的替代结构中，OASLM包括连接到其上的外部二极管，该二极管可操作以消散可能在DHFLC中积累的内部电荷。 读取DHFLC的激活的DHFLC像素区域可以通过传输或反射模式。

公开(公告)号：US11442314B2

公开(公告)日：2022-09-13

申请号：US17393750

申请日：2021-08-04

申请人： Chongchang Mao

发明人： Chongchang Mao

IPC分类号： G02F1/133 ,  G02F1/13363 ,  G02F1/1343

摘要： A polarization insensitive optical phase modulator is provided including a glass substrate; a liquid crystal element; a first electrode on a first surface of the liquid crystal element adjacent the glass substrate; a second electrode on a second surface of the liquid crystal element, opposite the first surface, the first and second electrodes supplying an electric potential across the liquid crystal element to drive liquid crystals in a predetermined configuration; and a silicon backplane on the second electrode opposite the liquid crystal element. The first electrode is a transparent electrode to a selected wavelength and is on a surface of the glass substrate. The second electrode includes individually addressable pixels and reflection metal mirrors on pixel surfaces and is on a surface of the silicon backplane. The modulator further includes a polymer quarter-wave plate (QWP) between the second electrode and the liquid crystal element, the polymer QWP having an optical axis at 45 degrees to liquid crystal slow axis.