公开(公告)号：US3840741A

公开(公告)日：1974-10-08

申请号：US39841973

申请日：1973-09-18

Applicant: BELL TELEPHONE LABOR INC

Inventor： MELCHIOR H

IPC: G01J1/02 ,  G02B6/14 ,  G02B6/34 ,  G02B6/42 ,  G02B27/00 ,  H01L29/66 ,  H01L31/10 ,  H04B10/18 ,  G01J3/34 ,  G02B5/14

CPC classification number: H04B10/25133 ,  G02B6/12007 ,  G02B6/29394 ,  G02B6/4215 ,  H04B2210/252

Abstract: The propagation in an optical fiber of an incoherent optical signal pulse containing a moderate spread of optical wavelength carrier components, such as supplied to the optical fiber by a light emitting diode (LED) source, results in a broadening (distortion) of the optical output signal emerging from the fiber. This distortion is caused by the fact that different optical wavelengths propagate at different velocities through the fiber material, that is, by the dependence of refractive index upon wavelength (material dispersion); and also by the fact that different optical modes propagate at different velocities (mode dispersion). In order to compensate for such distortions, a semiconductor charge carrier drift delay line is located in the path of the optical radiation emanating from the fiber. Advantageously, this semiconductor delay line is depleted of bulk majority charge carriers by means of a reverse voltage bias and is terminated by a charge carrier detector having an inherent gain (such as an avalanche diode or a transistor). The delay line is arranged such that the time delays of different wavelengths or modes in the fiber are compensated by the different drift time delays of the charge carriers generated by the different wavelengths or modes absorbed at different locations in the semiconductor delay line. In the case of mode dispersion compensation, the s

公开(公告)号：US3836243A

公开(公告)日：1974-09-17

申请号：US26658672

申请日：1972-06-27

Applicant: BELL TELEPHONE LABOR INC

Inventor： MELCHIOR H

IPC: G09G3/18 ,  G02F1/13 ,  G02F1/133 ,  G03F7/20 ,  G09F9/00 ,  G11C11/22 ,  G11C11/42 ,  H04N5/74 ,  G03B21/00 ,  G03B21/60

CPC classification number: G03F7/70291 ,  G02F1/132 ,  G11C11/22

Abstract: A system in accordance with the present invention utilizes a thermally addressed liquid crystal display cell as an imaging device in, for example, a schlieren optics projection arrangement. In preferred embodiment, the display cell includes a layer of liquid crystal substance, sandwiched between a first optically transparent heat-producing electrode, a second electrode, and transparent support substrates. The electrodes and the liquid crystal layer are supported by and contained between the support substrates. A controlled laser beam selectively generates hot spots in the heat-producing electrode which, in turn, locally heat the liquid crystal substance above its transition temperature. When the liquid crystal substance is subsequently cooled to its mesophase, long-lasting lightscattering centers remain. These long-lasting light-scattering centers are erased by applying a relatively high-frequency a-c voltage to the electrodes.

Abstract translation: 根据本发明的系统利用热寻址液晶显示单元作为例如色散光学投影装置中的成像装置。 在优选实施例中，显示单元包括夹在第一光学透明发热电极，第二电极和透明支撑基板之间的液晶物质层。 电极和液晶层由支撑基板支撑并容纳在支撑基板之间。 受控激光束选择性地在发热电极中产生热点，其又将液晶物质局部加热到高于其转变温度。 当液晶物质随后被冷却到其中间相时，保持持久的光散射中心。 通过向电极施加相对高频率的a-c电压来消除这些持久的光散射中心。