IR Laser detector

Thread Starter

tsunamiSam

Joined Jan 11, 2022
6
Hey all, Hope you're all well.

I've been looking over the past few days for a specific type of IR Laser detector system I require for a design project underway.

To explain quickly what I need is basically a system (as small as possible) that can detect an IR laser (in multiple wavelengths) and in turn, once this IR laser has been shone over this "receiver" ill call it, it causes a small LED to switch on, until the IR laser moves on, or is no longer detected.

For example, there's a powerful IR laser, shining 1200 meters let's say, automatically sweeping left to right constantly, when the laser sweeps over the specific area where this "receiver" is placed 1200 meters away, the small LED light turns on, then off once the laser sweeps back the other way the LED switches off.

Can anyone help link a series of parts that exist to make this happen or specific parts that I could assemble together in a circuit to make this happen laser detection and led on/off series?

Many thanks for your help!
 

Reloadron

Joined Jan 15, 2015
6,322
Red or Green LASER? Each has their good and bad features. Just for basic hobby experiments I have used these as detectors. If you wish to get serious at 1200 meters and can hold a narrow beam diameter look at surveyor LASER systems. Typical red LASER wavelength is about 630 nm to 670 nm give or take.

Welcome to the forums.

Ron
 

Yaakov

Joined Jan 27, 2019
3,983
The distance to the laser is not important on its own. The incident power at the detector is.

At 1200m the dispersion and attenuation of the laser source will be substantial, but how much power you start with is critical.

We can assume you will be working with a very small signal since any very powerful IR laser would not be "sweeping" at 1200m, it's too dangerous. So, with the very small signal and indeterminate frequency, also, lack of modulation, I am not too hopeful you can engineer a small cost-effective device to do what you are asking.

If you want to try, you will need to calculate the incident power you have to work with and then look for an IR sensor that works in the band you are interested in and can respond meaningfully and differentially (since there will probably be other signals in the band of interest) to a small, unmodulated signal.
 

Thread Starter

tsunamiSam

Joined Jan 11, 2022
6
Thanks for that YaaKov. The actual IR laser emitter is military grade, used or surveillance. So yeah I’ll have to loom around. I want the person to be alerted by a small LED if the ir laser is pointing at their location. If that makes sense! :)

thanks for your help! :)
 

Yaakov

Joined Jan 27, 2019
3,983
I suspected that, but the trouble is going to be the very small signal you will have to work with. The devices that receive the reflected signal are not going to be small, and probably include sophisticated filtering and modulation, if not cooling to make the sensor more capable.

It's really not an easy project at all.
 

Thread Starter

tsunamiSam

Joined Jan 11, 2022
6
Thanks YaaKov!
I’ve just discovered this, which reading the description fit what I need, in terms of detecting and altering a IR laser. Just need to change the alarm for a LED for a silent alert.
I just need the system inside the bodywork so I can adapt it to my own design needs.
 

Yaakov

Joined Jan 27, 2019
3,983
There are no specifications for that device other than the operating band. I am very uncertain about the legitimacy of it. There is no price, either. Importantly, there is no sensitivity information.

Your biggest problem is going to be sensitivity and selectivity. Even if that device is operational and of good quality, it is likely to be very expensive. It would also require very good knowledge of the devices and circuits involved.

As I mentioned, your first task is to work out how much power the incident IR light will have for your scenario. Then you also need to work what if any other sources of IR in the band of interest will be in the sensors field of view.

If you are just trying to detect an IR illuminator, you might have some success, but I suspect it will only operate well at closer ranges where the power is higher.
 

Janis59

Joined Aug 21, 2017
1,379
The over-kilometer far light-ray barrier problem is long ago solved. Yet then in eighties was bit other element base for realizing the sinchronous detection, namely 150 YD13 chopper and 140YD20 amplifier but nowadays exist easy and cheap to get IC like LM567 or as well CD4046 PLL. Just solder the sinchronous detection and laser power may be diminished hundredfold or maybe even thousandfold.
 
Top