公开(公告)号：US20150292941A1

公开(公告)日：2015-10-15

申请号：US14437794

申请日：2013-10-24

Applicant: CSIR

Inventor： Andrew Forbes ,  Christian Schulze ,  Michael Rudolf Duparré ,  Sandile Ngcobo

IPC: G01J1/42 ,  G01J9/00 ,  H01S3/00 ,  G01J1/04

CPC classification number: G01J1/4257 ,  G01J1/0407 ,  G01J1/0411 ,  G01J1/0437 ,  G01J1/4228 ,  G01J9/00 ,  G01J2009/004 ,  H01S3/0014 ,  H01S3/005 ,  H01S3/08054 ,  H01S3/0815 ,  H01S3/09415

Abstract: A method and apparatus for performing a modal decomposition of a laser beam are disclosed. The method includes the steps of performing a measurement to determine the second moment beam size (w) and beam propagation factor (M2) of the laser beam, and inferring the scale factor (wO) of the optimal basis set of the laser beam from the second moment beam size and the beam propagation factor, from the relationship: wO=w/M2. An optimal decomposition is performing using the scale factor wO to obtain an optimal mode set of adapted size. The apparatus includes a spatial light modulator arranged for complex amplitude modulation of an incident laser beam, and imaging means arranged to direct the incident laser beam onto the spatial light modulator. Fourier transforming lens is arranged to receive a laser beam reflected from the spatial light modulator. A detector is placed a distance of one focal length away from the Fourier transforming lens for monitoring a diffraction pattern of the laser beam reflected from the spatial light modulator and passing through the Fourier transforming lens. The apparatus performs an optical Fourier transform on the laser beam reflected from the spatial light modulator and determines the phases of unknown modes of the laser beam, to perform a modal decomposition of the laser beam.

Abstract translation: 公开了一种用于执行激光束的模态分解的方法和装置。 该方法包括以下步骤：执行测量以确定激光束的第二力矩光束尺寸（w）和光束传播因子（M2），并推断来自激光束的激光束的最佳基准集的比例因子（w0） 二次波束尺寸和波束传播因子，从关系：wO = w / M2。 使用比例因子wO执行最佳分解以获得适应尺寸的最佳模式集合。 该装置包括布置成用于入射激光束的复振幅调制的空间光调制器，以及被配置为将入射激光束引导到空间光调制器上的成像装置。 傅立叶变换透镜被布置成接收从空间光调制器反射的激光束。 离开傅里叶变换透镜放置距离一个焦距的检测器，用于监测从空间光调制器反射并穿过傅里叶变换透镜的激光束的衍射图案。 该装置对从空间光调制器反射的激光束进行光学傅立叶变换，并确定激光束的未知模式的相位，以执行激光束的模态分解。

公开(公告)号：US09588488B2

公开(公告)日：2017-03-07

申请号：US14173010

申请日：2014-02-05

Applicant: CSIR

Inventor： Sandile Ngcobo ,  Ihar Anatolievich Litvin ,  Liesl Burger ,  Andrew Forbes

IPC: G03H1/02 ,  G03H1/08 ,  G03H1/22 ,  G03H1/00 ,  H01S3/105 ,  H01S3/081 ,  H01S3/0941 ,  H01S3/16

CPC classification number: G03H1/08 ,  G03H1/0005 ,  G03H1/2286 ,  G03H1/2294 ,  H01S3/0815 ,  H01S3/09415 ,  H01S3/105 ,  H01S3/1611 ,  H01S3/1643 ,  H01S2301/20 ,  H01S2301/203

Abstract: Laser apparatus includes an output coupler, a gain medium for generating laser light, a rear optical element, and an input coupler. The input coupler is arranged to direct a pump beam to the gain medium and to define an optical path between the output coupler and the rear optical element. The rear optical element is a spatial light modulator arranged to act as an intra-cavity digital holographic mirror which can be digitally addressed. The spatial light modulator displays selectively a gray-scale image of a hologram thereby to phase-modulate laser light in the cavity, thus making it possible to generate an output laser beam having a desired characteristic. The apparatus includes a computer arranged to generate at least one hologram corresponding to a desired output beam characteristic, and a driver circuit responsive to an output from the computer to generate a corresponding gray-scale image of the hologram on the spatial light modulator.

Abstract translation: 激光装置包括输出耦合器，用于产生激光的增益介质，后部光学元件和输入耦合器。 输入耦合器布置成将泵浦光束引导到增益介质并且在输出耦合器和后部光学元件之间限定光路。 后部光学元件是空间光调制器，其布置成用作可以数字寻址的腔内数字全息镜。 空间光调制器选择性地显示全息图的灰度图像，从而相位调制空腔中的激光，从而可以产生具有期望特性的输出激光束。 该装置包括计算机，其布置成产生对应于期望输出光束特性的至少一个全息图，以及响应于来自计算机的输出的空间光调制器上的全息图的相应灰度图像的驱动器电路。

公开(公告)号：US20210234328A1

公开(公告)日：2021-07-29

申请号：US16972075

申请日：2019-06-04

Applicant: CSIR

Inventor： Lebohang Teboho Bell ,  Sandile Ngcobo

IPC: H01S3/109 ,  H01S3/0941 ,  H01S3/16 ,  H01S3/06 ,  H01S3/10

Abstract: A frequency double or mixing laser includes a laser pump, a rear optical element, a Brewster window, a laser generator medium, an output coupler and a nonlinear crystal located inside the resonator cavity. The nonlinear crystal may be located inside the resonator cavity before the output coupler. The laser may further include at least one optical element that controls the phase or/and the amplitude of the fundamental laser beam to a high-order.