公开(公告)号：US5034334A

公开(公告)日：1991-07-23

申请号：US420867

申请日：1989-10-13

申请人： Edward J. Flynn ,  Carl J. McGrath ,  Paul M. Nitzsche ,  Charles B. Roxlo

发明人： Edward J. Flynn ,  Carl J. McGrath ,  Paul M. Nitzsche ,  Charles B. Roxlo

IPC分类号： H04N7/22 ,  H01S5/00 ,  H01S5/068 ,  H01S5/40 ,  H04B10/00

CPC分类号： H01S5/0014 ,  H01S5/06812 ,  H01S5/40 ,  Y10S148/095 ,  Y10S148/162

摘要： An advantageous method of fabricating lasers adapted for use in a multichannel analog optical fiber communication system, e.g., a CATV system, is disclosed. A laser generally can be used in such a communication system only if it meets, inter alia, very stringent intermodulation specifications. To identify such lasers typically requires extensive testing. It has now been discovered that certain readily determinable parameters can be used to predict the intermodulation behavior of a given device. This discovery makes possible a simpler, and therefore less costly, process of identifying suitable lasers, resulting in a more economical method of making lasers for the stated application. The method comprises measuring the light versus current (L versus I) characteristic of a given laser, determining therefrom the first, second, and possibly higher, order derivatives of L with respect to I, and determining thereform a parameter that is a predictor of the distortion behavior of the laser. Exemplarily, the quantity is the normalized second order distortion (2HD/C), defined as 20 log (mL"/4L'.sup.2), where m is the modulation index, and L' and L" are the first and second derivatives, respectively, of L. 2HD/C has a pronounced minimum at I=I.sub.op , the current at which L"=0. Advantageously, lasers are selected that have 2HD/C less than a predetermined value (e.g., -70 dbc, with m=0.04) over a relatively wide current range (e.g., at least 4 mA).

公开(公告)号：US5020049A

公开(公告)日：1991-05-28

申请号：US420849

申请日：1989-10-13

申请人： George E. Bodeep ,  Thomas E. Darcie ,  Edward J. Flynn ,  Jan Lipson ,  Carl J. McGrath ,  Charles B. Roxlo ,  Mark S. Schaefer ,  L. C. Upadhyayula

发明人： George E. Bodeep ,  Thomas E. Darcie ,  Edward J. Flynn ,  Jan Lipson ,  Carl J. McGrath ,  Charles B. Roxlo ,  Mark S. Schaefer ,  L. C. Upadhyayula

IPC分类号： H01S5/00 ,  H01S5/062 ,  H01S5/227 ,  H04B10/142 ,  H04J14/02 ,  H04N7/22

CPC分类号： H04N7/22 ,  H01S5/06213 ,  H04B10/58 ,  H04J14/0298 ,  H01S5/0035 ,  H01S5/227 ,  H01S5/2275

摘要： An amplitude-modulated vestigial-sideband, television channel sub-carrier multiplexed optical fiber transmission system includes a laser diode operating linearly throughout the desired range of multiplex frequencies. Such linear laser diode operation is accomplished by limiting leakage current within the laser diode to a very low level. The composite second-order distortion in the optical output signal from the laser diode is down typically 50 db from the video carrier for each channel. For some laser diodes that exhibit slow turn-on in the L-I characteristic, there is a point of inflection in the L-I curve. Operation with the laser biased at or near this point results in extremely linear performance, even though the laser may have insufficient blocking of leakage current to otherwise produce acceptable linearity.

摘要翻译： 幅度调制的残留边带，电视频道副载波复用光纤传输系统包括在整个期望的多路复用频率范围内线性地工作的激光二极管。 这种线性激光二极管操作是通过将激光二极管内的泄漏电流限制到非常低的水平来实现的。 来自激光二极管的光输出信号中的复合二阶失真通常为每通道的视频载波降低50db。 对于在L-I特性中呈现缓慢导通的一些激光二极管，在L-I曲线中存在拐点。 激光偏置在此点附近的操作导致非常线性的性能，即使激光器可能没有足够的阻挡泄漏电流，从而产生可接受的线性度。

公开(公告)号：US5012484A

公开(公告)日：1991-04-30

申请号：US459922

申请日：1990-01-02

申请人： Edward J. Flynn ,  Leonard J. Ketelsen ,  Charles B. Roxlo

发明人： Edward J. Flynn ,  Leonard J. Ketelsen ,  Charles B. Roxlo

IPC分类号： H01S5/028 ,  H01S5/06 ,  H01S5/062 ,  H01S5/0625 ,  H01S5/10 ,  H01S5/12 ,  H04B10/155

CPC分类号： H01S5/12 ,  H04B10/504 ,  H04B10/564 ,  H04B10/58 ,  H01S5/028 ,  H01S5/06 ,  H01S5/06213 ,  H01S5/06255 ,  H01S5/06258 ,  H01S5/10 ,  H01S5/124 ,  H01S5/1243

摘要： Lasers for use in multichannel analog optical fiber communication systems (e.g., of the type contemplated for CATV) have to meet very stringent requirements, including high linearity. DFB lasers are advantageously used in such communication systems. Typically only a relatively small percentage of the nominally identical DFB lasers on a wafer meet the specifications. It has now been discovered that the likelihood that a given DFB laser will meet the requirements is substantially increased if the laser comprises means that are adapted for producing a non-uniform photon density in the laser cavity, with the density of photons being larger in the rear portion of the cavity than in the front portion, such that during operation of the laser the gain in the back portion is substantially independent of the laser current, whereas the gain in the front portion is a function of the laser current. Exemplarily, lasers according to the invention have power asymmetry less than about 5. Preferred embodiments are AR/HR lasers with KL in the range 1.6-2.5. Optionally lasers according to the invention have a phase shift located in the back portion of the grating, a split contact, and/or a non-constant mesa width.

公开(公告)号：US06725607B1

公开(公告)日：2004-04-27

申请号：US10139546

申请日：2002-05-06

申请人： Edward J. Flynn

发明人： Edward J. Flynn

IPC分类号： E04H304

CPC分类号： B66B29/04 ,  E04F11/00 ,  E04F2011/1868

摘要： A safety device and method for stairs, escalators and moving sidewalks that moves a person sitting or sliding on a handrail onto the steps to avoid accidents. The safety device includes a sloped surface that can be part of an elongated pyramid. The sloped surface is at an angle of between about 30° and about 45° from the direction of the handrail, with 45° being preferred. The safety device is free of sharp edges and is configured to avoid catching on a person's clothing. The safety device may include illumination.

摘要翻译： 一种用于楼梯，自动扶梯和移动人行道的安全装置和方法，其将坐在或扶手上的人移动到台阶上以避免事故。 安全装置包括可以是细长金字塔的一部分的倾斜表面。 倾斜表面与扶手方向成约30°至45°之间的角度，优选45°。 安全装置没有锋利的边缘，并被配置为避免抓住人的衣服。 安全装置可以包括照明。