2024年1月12日发(作者：)

Build the long range Laser Spy system

建立系统的远程激光间谍

The Laser Spy System is considered by many to be the Holy Grail of high tech spy devices

because it can give the user the ability to listen in on conversations that take place in a distant

building without having to install a bug or transmitter at the location. The Laser Spy System was

said to be invented in the Soviet Union by Leon Theremin in the late 1940s. Using a non-laser

based infrared light source, Theremin's system could detect sound from a nearby window by

picking up the faint vibrations on the glass surface. The KGB later used this device to spy on the

British, French and US embassies in Moscow. It is also interesting to note that Leon Theremin

invented the world's first electronic instrument, a wand operated synthesizer named "The

Theremin" after him.

激光间谍系统是被许多人认为是高科技间谍装置的圣杯，因为它可以给用户窃听到发生在遥远建筑中的谈话，而不用在建筑物内放置一个窃听器或是发射机。激光间谍系统据说是由前苏联的莱昂特雷门在20世纪40年代发明的。通过使用一个非基于激光的红外光源检测玻璃表面的微弱震动。克格勃后来使用这种设备来窃听莫斯科的英国、法国和美国大使馆。有趣的是还注意到，莱昂特雷门发明了世界上第一台电子乐器，一种以他名字命名的，用棒子操作的合成乐器。

The Laser Spy System goes by several names such as the Laser Microphone, Laser Listener,

Laser Bug, Window Bounce Listener and a few similar names. The Laser Spy certainly works well

under ideal conditions, but it has many strengths and weaknesses that will be discussed in this plan.

Building your own Laser Spy is by far the best way to experiment with this technology as you can

adjust the design to suit your needs, rather than forking over hundreds or thousands of dollars for

an assembled kit that will likely be far inferior to one that you can build yourself. Many of the kits

I have seen for sale over the Internet not only use dated technology, but they incorrectly state that

the system uses a modulated laser beam to convert window vibrations into sound, which is simply

not the case. Let's put the mysteries to rest once and for all and build a working Laser Spy System

from the ground up and explore the functionality of each subsystem that makes a working unit.

激光间谍系统有不同的名字，如：激光麦克风、激光监听器、激光窃听器、窗口反弹监听器等几个类似的名字。激光间谍在理想情况下可以工作的很好，但它也有许多优点和不足，下面这个计划中将讨论到这一点。到目前为止，制作你自己的激光间谍系统最好的方法是用以下这个技术来做实验，以使你可以调整你的设计来适应你的需要，而不是不情愿的付出几百上千美元来买一套组装器件，那样将会远劣于你自己做的。我从网上看到的出售的组装套件，不仅使用的是过时的技术，并且他们错误的表述为，该系统使用了调制激光束来将窗口震动转换为声音，这完全不是这么回事。让我们把这个奥秘一劳永逸，并且从地面上制作一个工作的激光间谍系统，并探讨这些组成一个完整的工作单元的子系统的功能。

We will be starting with an ultra basic proof of concept test system that will show you how

the Laser Spy converts vibration into sound and how careful alignment of both the laser and

receiver are required for optimal performance. Ironically, the most basic configuration may prove

to be the most useful, and the $20 you spend in parts could create a system that works as well (or

better) than some of the ones that are for sale on the internet for thousands of dollars. As you will

find out, the key to spying with a laser beam is in the alignment and reception of the beam, not

some magical black box full of fancy filters and optical components.

我们将开始与超系统的基本概念证明测试将告诉你如何转换成激光间谍声音，并且需要多么仔细将激光和接收器列成一条直线以最好的展示。讽刺的是，大多数基本构造也许会证明是最有用的，并且你花20美元在上面就可以制作出一个，这个系统可以比那些网上卖几百上千的系统工作的一样好（甚至更好）。随着你会发现，间谍器的关键是激光束和接收器在同一条直线上，而不是一些有着神奇的想象中的滤波器和光学元器件的黑盒。

Figure 1 - You will need some type of laser to bounce off of the target window

图1——你将会需要几种激光来反射目标窗户。

The obvious first component in the Laser Spy system is the laser, which will target a distant

reflective object and send the beam back to your receiver for decoding. Before digging deep into

this project, let me explain how this system works, and dispel some of the myths that are

circulating on the internet regarding the operation of this device. First of all, these laser spying

devices do NOT work on modulation of the laser beam like some laser communication devices.

Modulation of the laser beam is impossible because it would take some type of circuitry installed

in the laser driver to actually modulate the intensity of the beam, and the laser is going to be

installed at your location, not the target location. The principal that is at work here is not

modulation, but movement! As the laser reflects from the target window, the slight vibrations from

conversations or noise that vibrate the windows cause a very slight change in position of the

returning laser beam. This change in position is converted into voltage as the sensor in the receiver

catches the returning laser beam. This is why the optimal operation of the receiver requires the

laser beam to be slightly offset from the phototransistor as will be shown. So movement, not

modulation the principal on which this system operates.

很明显，激光间谍系统的首要元器件是激光，它将把远处的带反射性的物体作为目标，并把光束反射回接收器编码。在深入研究这个项目之前，让我们解释一下这个系统是如何工作的，并消除一些互联网上流传关于该设备操作的误解。首先，这个激光间谍和一些激光通讯设备一样，不是用激光来调制。激光调制是不可能的，因为它将要用几种电路来安装在激光驱动中来调制激光的强度，并且这个激光将要安装在你的位置，而不是目标位置。这里主要工作的不是调制，而是偏置。当激光从目标窗户反射时，来自谈话或是噪声的振动源使窗户震动在反射回的激光束上引起一个非常轻微的在位置上的改变。这个位置上的改变被转换成电压，随着接收器上的传感器接收到返回的激光。这就是为什么就受气的最佳操作需要激光束来显示来自光电管的偏置。所以主要是偏置，而不是调制是这个系统工作。

You can use any laser you like for this project, and there will be no quality difference

whatsoever between a state-of-the art lab laser and a $2 pointer. The only disadvantage to using a

cheap laser pointer is that you will have to modify it for an external battery pack if you plan to

have it on for more than a few minutes at a time, but that is an easy task. Also, a visible red or

green laser will not allow for covert operation due to the fact that it is very easy to pinpoint the

source of a laser beam, especially at night. For this reason, a visible laser is used for initial

daytime targeting and then an invisible infrared laser is switched for optimal long duration and

night time operation. Of course, this all depends on your intended use, and for demonstration

purposes a visible red laser is best.

你可以用任何你喜欢的激光用于这个项目，并且一个国家最先进的实验室激光与一个2美元的激光在质量上没有什么差别。使用便宜激光的唯一缺点就是，如果你计划在一次使用中使用的时间长一点的话，你就不得不多加一个外接电池组，但这是一个简单的任务。此外，一个。

Figure 2 - A small speaker will be used to simulate a vibrating window

图2——一个小喇叭将被用来模拟振动窗口

The first time I experimented with a laser spying device was in the 1980s when I found a

DIY article in an electronics magazine. Lasers were huge, expensive beasts back then, but I was

nerdy enough to have one to mess around with and followed the instructions in the article. In the

end, the system was found to be 100% useless, and rumor at the time suggested it was all just a

hoax. What happened was that the article failed to mention that as cool as this device was, it was

extremely difficult to set up in the real world, especially when trying to bounce from a distant

window. Believe me when I say that this device does indeed work, but using it to spy across the

street will require a serious amount of setup, fine tuning and patience. To be perfectly honest, your

chances of simply beaming toward your neighbor's window and hearing anything are about 1,000

to 1 against you. So many factors have to be in your favor, such as the type of window, the

alignment of the structure, the time of day, the level of sound, and mostly, your patience level. I

have done a successful window bounce from across a city street, but it was NOT an easy task, so

keep that in mind. Any site selling this device in kit or plans form claiming that it is "point and

shoot" should be deleted from your favorites in a hurry!

第一次我用激光间谍做实验是在20世纪80年代，当时我在一个在电子杂志自己动手做的文章。激光当时是巨大的昂贵的怪兽。但我是一个十足的书呆子，为了有一个摆弄就按照文章中的说明做。最后，+这个系统被证明是百分百没有用，并且那时谣传这根本就是一个恶作剧。事情是这样的，文章没有提到，像这个装备一样酷的是，它极难在现实世界中实现，尤其是当试图从一个遥远的窗口反射时。相信我所说的，这个设备确实工作，但使用它来窃听街对面将需要一系列的设置，微调和耐心。老实说，就这样简单的将光束投向你的邻居的窗户，你听到任何东西的机会是千分之一。所以诸多因素都是对你有利,如类型的窗口,对准的结构,一天的时间,声音的等级,并在很大程度上,你的耐心水平。我已经成功的做了一个窗口反射实验穿过一条城市的街道，但它不是一个轻松地任务，因此记住这点。任何网站卖这种装置在组件或计划形式中声称这是“点射击”应立即从你的喜爱网站中删除。

To create a "test window" to allow the deflection of the laser beam, a small speaker is

connected to some audio source such as a radio or computer headphone port. Don't worry about

how loud the audio source will be; as long as you can just barely hear the sound on the speaker, it

will be good enough. Any small radio or portable music system will have a headphone jack that

you can connect to your speaker. The size of the speaker is also not important as long as it is large

enough so that you can glue a small bit of mirror to the center cone to allow a surface to deflect

the laser beam. Some speakers already have a chrome dome in the center, so if you can find one

like that, then you will not need to use the mirror. Solder the appropriate jack to the speaker

terminals; this will likely be a 1/8 inch headphone jack.

为了创建一个“窗口”来测试的偏置情况,一个小的扬声器雷射光束被连接到一些音频源,如在一个电台或电脑耳机的接口。不用担心音频源要多大，只要你可以基本上听到扩音器中的声音，就足够了。任何小小的无线电或便携式音乐系统将有耳机接口,你可以连接到你的扩音器。扩音器的尺寸不是非常重要，只要足够大到以便于你可以用胶水在中间粘住一小块镜子来使激光束偏转。一些扬声器在中间已经有了一个铬圆，因此你可以找一个像那样的，那你就不必用镜子了。把适当的接口焊接在扬声器终端上；这将会是一个1/8 英寸的耳机接口。

Figure 3 - Add a reflective surface to the center of the speaker

图3——在扬声器的中央加一个反射表面

Any small piece of a highly reflective surface such as a mirror can be used to deflect the laser

beam during these tests. A mirror works best, and a piece can be snapped from an old mirror using

pliers or a small dental mirror can be taken apart for to remove the small round mirror from the

plastic housing. A hot glue gun or even some double sided tape can be used to glue the small

mirror section to the center of the speaker. The size of the mirror is not important since the laser

beam will only be a few millimeters across when it strikes the surface. If you intend to snap a bit

off a larger mirror, use a cloth or paper towel to wrap the corner so that small slivers of glass do

not fly from the mirror as you break it. A highly reflective plastic or metal surface will also work

for this experiment, and even a shiny dime will do the job in a pinch.

任何小片的具有高反射性表面例如一面镜子就可以在测试期间用来偏置激光。一面镜子最好，也可以用一片使用钳子从老镜子或是小牙科镜中把小圆镜从塑料外壳中分离。一个热胶枪甚至双面胶带可用于把小镜子粘在扬声器的中间。镜子的尺寸不重要是因为激光仅有几毫米左右当它到达镜子表面时。如果你打算打碎一大块镜子，用一块布或是一张纸巾包住以便于当你打碎它时小碎片不会乱飞。一片高反射的塑料或者是金属表面对这个实验来说一样行得通，甚至一个闪闪发亮的一角硬币能胜任这项工作的问题啰。

Figure 4 - Feeding an audio source into the speaker

图4——输入一个音频源给扬声器

The speaker needs to be driven by some audio source, but the level should be so low that you

can only hear it when your ear is right next to the speaker. The goal is to recreate the same

conditions that you will be dealing with during your covert spying operations, so the reflective

surface should just barely be vibrating. A portable audio player is perfect for this test because it

has a low power amplifier and will run for hours at a time. Set your player to loop indefinitely and

then adjust the volume as low as it will go until you can just barely hear the output from the

speaker.

扬声器需要由一些音频源驱动，但强度应该非常低以至于你需要用耳朵正对着扬声器你才能听得到。我们的目标是重建相同的条件，那样你就可以在期间处理你的秘密间谍任务，因此反射表面应该刚好被震动。一个便携式播放器是个很好的选择用来测试，因为这个播放器有低功耗的放大器，并且每次都可以运行一个小时。设置你的播放器为无限循环，然后在能运行时调整音量直到你能勉强从扬声器中听到输出。

Figure 5 - Creating an easy to align speaker base

图5——创建一个容易对齐扬声器基地

The alignment of the laser from the source to the target and back is not a trivial task, and as

you increase the distance from the laser to the target, you also increase the error level. At 500 feet,

the beam will become so sensitive to displacement that you will have to be careful when moving

around the laser because the deflection of the floor inside your home will be enough to throw the

beam out an inch or more. When I finally managed to setup a successful long range configuration,

I found that the alignment was so sensitive that even a passing car would create waves in the

system due to the vibrations between the house and the road. The laser Spy Device is certainly

capable of working for many hundreds of feet away (even across a few city blocks), but vibration

would become so critical that you would probably need to have everything mounted on an

extremely heavy concrete or metal base secured to the ground. These are things you will find out

as you experiment with this project.

激光对准从来源到目标再回来并不是一个微不足道的任务，并且随着你增加激光到目标的距离，你也会增加错误的级别。在500英尺，光束将变得如此对位移敏感,你将不得不非常小心当在激光周围走动时，由于地板的变形情况在你的家将足以把光投出来一英寸或更多。最终，当我成功的建立了一个远距离配置，我发现校准是如此的敏感以至于一辆路过的汽车，由于在房子与道路之间的振动，都会在系统中产生波形。激光间谍装置确实有能力在几百英尺(甚至穿越了几条街)外工作，但是振动将如此关键的是你可能需要把所有的都装在一个很重混凝土或金属底座固定在

地上。这些就是你在这个项目中做实验时会发现的。

To make your life easy when experimenting with the basic indoor setup, create some kind of

easily adjustable speaker stand like mine using an old webcam base or adjustable bench vice. The

ability to move the speaker to any angle and secure it will be key to testing the operation of your

Laser Spy device as you build it. The targeting laser will also need some kind of adjustable base as

well.

为了使你的生活更容易，当实验时用室内的实验设置，创造一种容易调节的扬声器，像我这样放在旧的摄像头底座或是可调节基座上。可将扬声器移动到任何角度和稳当的能力，将会是测试你的间谍设备运行的关键，当你建立他的时候。作为激光的目标也将需要一种可调节的基座。

Figure 6 - The adjustable window pane simulator ready to use

图6——可调窗玻璃模拟器可以使用了

The adjustable window pane simulator will really help when creating and debugging this

project, as it would be next to impossible to try to target a distant window without first knowing

what to expect in the captured audio signal or even if the unit is functioning properly. If the

original 1980s magazine article would have explained this, I might have had some success when I

first tried this experiment!

可调的窗玻璃模拟器将真正帮助创建和调试这个项目，因为他不可能试着去侦测一个遥远的窗口在不知道会捕捉到什么样的信号，甚至工作单元是否正常。如果20世纪80年代的杂志原作文章有解释这个，我也许会成功当我第一次尝试这个实验时。

Figure 7 - A photoresistor will respond to a change in light

图7——一个光敏电阻将响应光的改变

The purpose of this initial experiment is to verify that you can indeed listen to sound that is

vibrating a nearby reflective surface. In our case, it will be the small mirror glued to the speaker

cone that will vibrate due to either sound from the radio feeding it, or by having a helper talk

directly into the speaker as you listen for their voice at the receiver. This test receiver will be the

most basic system possible, consisting of only a CDS cell "cadmium sulfide photocell" feeding a

simple transistor amplifier that will convert the tiny changes in the laser beam position into

changes in voltage that will be sent to your headphones as an audio signal. Think of the laser beam

as being the "needle" on a record player and the vibrating window surface as the bumps in the

record groove.

本实验的初步目的是核实你确实可以听到在反射面附近振动的声音。在我们的例子中,它是小镜子,粘在扬声器中间将振动无论是来自收音机或是助手讲话直接给扬声器，而你从接收器中收听他们的声音。这个测试接收机将最基本的系统, 包括可能只有一个CDS细胞“硫化镉光电池”驱动一个简单的晶体管放大器，那将把激光位置的微小变化转化为电压的改变，这将作为音频信号发送到你的耳机上。把激光看作是播放器上的唱针，而把振动窗口看作是唱片上的凸起。

A CDS cell is basically a resistor that will change its impedance depending on how much

light strikes the surface. By feeding it to a battery connected in series and then into an audio

amplifier, the result is a light sensitive audio system that will allow you to "listen" to light.

Because this system has very little gain and no filtering, it will be a very minimal system, but will

certainly let you hear the secret audio signal being sent along your test laser beam. This basic

system would even work from hundreds of feet away if you could align the beam properly, which

is part of the difficulty in using a Laser Spy System. A CDS cell can be purchased for a few

dollars at most electronic suppliers, but if you don't want to wait for delivery or can't find one in

stock, just purchase a night light and rip it apart to extract the CDS cell. The CDS cell will be the

small disc with two leads and a will have a wavy line on its surface. Just unsolder the two leads or

bend the part back and forth until it frees itself from the tiny circuit board.

一个CDS电池基本上是一个会依据照射到表面的光强度来改变阻值的电阻。通过输入串联连接的电池，然后输入一个音频放大器，其结果是光敏感音响系统将使你“听”到光。因为本系统具有很小的增益且没有滤波，这将是一个非常最小系统,但肯定会让你听到这个被送沿着你的测试激光束传送的秘密音频信号。这个基本系统甚至可以从几百英尺外工作，如果你把激光正确对齐，这是使用这个激光间谍系统中困难的部分。一个CDS 电池可以在大多数电子配件店中花及美

元买到，但如果你不想等邮寄或是找不到一家店，就买一个小夜灯，拆了它并取出CDS电池。CDS电池有着带有两根导线的圆盘，并且表面有波浪线。就拆焊这两根导线或者是把那部分来来回回弯曲，直到它从电路板中脱落下来。

Figure 8 - All night lights will contain a photoresistor

图8——所有的小夜灯都有一个光敏电阻

The photoresistor I am using in the receiver experiment was taken from a dollar store night

light. The CDS cell is easily identified as the small disc behind the plastic lens. The internal

circuitry of the nightlight is much like the circuit that will be used here to convert the light into

sound. The change in resistance from the photoresistor is fed into the base of the transistor or

switch that controls the current to the small light bulb. In our case, the light bulb will become

headphones.

我在接受实验中使用的光敏电阻是从1美元的商店小夜灯中拆下来的。CDS电池很容易识别因为圆盘后面的塑料镜片。在夜灯的内部电路很像将用在这里转换成声光电路。光敏电阻的阻值变化反馈到晶体管或是控制当前灯泡的开关的基台。在我们的例子中，小灯泡将变成耳机。

Figure 9 - Setting up the laser and speaker on a test bench

图9——把激光和扬声器安装到工作台上

The laser will need to be installed on some type of adjustable stand or held in place at an

approximate horizontal position so you can target the speaker and then catch the reflected beam at

your breadboard. I clipped my red laser module into an adjustable bench vice so that it could be

aimed at the speaker and then locked into position. When setting up the laser and speaker,

remember that according to the law of reflection, "the angle of incidence equals the angle of

reflection". In other words, if your beam is lower than the speaker mirror, it will be bouncing back

to you at a higher angle. As the distance from the target increases, this deflection becomes much

greater. If you are feeling brave, try to bounce your laser back to your breadboard with the speaker

at the other end of your lab - I dare you!

激光需要安装在某种可调站的地方或持有一个近似水平位置,这样你就可以就找到目标扬声器然后在你的线路板上捕捉反射的光束。我把我的红色激光模块做成可调节的，以便于对准扬声器，然后就可以锁定它了。当安装好激光和扬声器，记住,根据反射定律,“入射角等于反射的角度”。换句话说，如果你的光束低于扬声器的镜子,它将给你反弹回来一个更高的角度。当距离增加时,这个反射角度要大得多。如果你感到勇敢,试图反弹激光回到你在实验室另一端的线路板——我敢跟你打赌！

Figure 10 - Schematic for an ultra simple light to sound converter

图10—— 一个超简单的光声转换器图解

The initial experiment using the photoresistor will only require a single NPN transistor,

resistor and a battery in order to prove that the laser beam is definitely capable of picking up faint

vibrations and changing them into audio. Any generic NPN transistor such as a 2N3904 or

2N2222 will work in this circuit. The battery voltage can be anywhere from 3 volts to 9 volts. If

you really want to go basic, then just run a 9 volt battery directly into the photoresistor and out to

the headphones, although without the transistor to amplify the signal, the audio will be very faint.

最初的用光敏电阻做的实验将只需要使用一个NPN晶体管、电阻和电池,以证明该激光绝对能够检测微弱振动并转换成音频。任何通用的NPN晶体管如2N3904或2N2222都可以在这个电路中工作。电池电压可以是3V到9V中的任一值。如果你真的想要很基础，那就只需直接给光敏电阻运行9V电并把输出给耳机，由于没有晶体管放大信号，音频将是非常微弱的。

This basic light to sound converter works because any change at the base of the transistor will

amplify the current to the headphones. Since the return laser beam will be bouncing around due to

the vibration at the speaker, this will cause the headphones to respond to the beam as if it was an

audio signal. Although the laser beam is moving, not modulated, the principals at work are exactly

the same with the exception that in this configuration, the beam needs to be slightly offset from

the center of the photoresistor so that when it moves across the surface, there is a corresponding

change in voltage. If the principal at work here was in fact modulation, then a direct hit onto the

surface of the photoresistor would be optimal.

这个基本的光转换器能工作，是因为晶体管的任何改变都会扩大到耳机。由于返回的激光束因为扬声器的振动会弹跳，这将引起耳机回应激光好像是一个音频信号。尽管光束是在偏置，而不是调制，在这个调制中，主要工作有着相同的例外，光束需要一些轻微的位移从光敏电阻的中心,以便于在表面移动时,都有一个相应的改变电压。如果这里工作主要是调制，那么直接命中光敏电阻的中心将是最佳的。

Figure 11 - Targeting the photoresistor with the laser beam

图11——用激光束瞄准的光敏电阻

on your audio source and adjust the volume so you can barely hear the output on your

speaker and then set up the laser and receiver so that the beam strikes the front face of the

photoresistor. As soon as the beam hits the photoresistor, the impedance will vary significantly and

you will hear a pop and probably a bunch of noise. Play around with the position of the beam to

see how the position of the beam on the face of the photoresistor alters the reception of the audio

signal. You will see that the optimal position for the beam is just touching the surface of the

photocell so that any changes in the beam position from the vibrations will result in the most

significant swing in voltage at the output of your headphones. If all you hear is a loud hum, then

you probably have too much ambient light in your room. Incandescent light bulbs actually vibrate

at 50 or 60 Hertz, and you will hear that in your system as a loud constant hum. As you have

probably guessed, the Laser Spy system will not perform very well in the daytime due to ambient

light sources competing with your laser beam, but this is fine since real spies usually operate in the

darkness!

靠近你的音源并调节音量到几乎听不到, 然后设置激光和接收器,以便于激光可以射中光敏电阻的表面。当光束打到光敏电阻,阻抗将会变化很大,你将可能听到一个流行，或是一堆噪音。改变光束的位置，看看光敏电阻表面的光怎样改变音频信号。你会发现光束最优的位置只是刚触摸到光电池的表面,这样任何光束位置上来自振动的变化会导致在输出的耳机最重要的电压波动。如果你听到的一个大声的哼声,那你可能在你的房间里有太多的外界光。其实白炽灯为50或60赫兹的振动,你会听到一声在你的系统不断哼唱。你可能已经猜到,激光间谍系统不会在白天表现非常好,由于外界光源与激光互相竞争，但是这很好因为真正的间谍通常在黑暗中操作!