Laser Beam Question

[polonos13]

Hi everybody !!!
I m just new to the laser world and i want to make a laser harp and i am looking for the suitables laser modules.
I want to know which is the factor that tells me if a laser beam is visible by the eye (is the mw ?).

Does any of the two below products has a visible by the eye laser beam ?

LASER DIODE 5mW 2.5-4V HLDPM12-635-5 - -
LASER DIODE 10mW 2.5-4V HLDPM12-655-10 - -

I m asking for your opinion about these specific products,cause i m from Greece and the seller is from Greece too.

Thanks in advance !

 

[udanis]

Does any of the two below products has a visible by the eye laser beam ?

No, they are too weak. Now if they were 532nm and of the same power you could see the beam in the dark.

I want to know which is the factor that tells me if a laser beam is visible by the eye (is the mw ?

That will be a combination of the mw and nm. mw is the output of the laser, the bigger that number the brighter it is. nm is the wavelength of the laser. The closer the laser is to ~550nm the brighter It will be because the human eye is most sensitive to that wavelength. To be safe I would use 5mw 532nm ir filtered modules

 

[chipdouglas]

yes those will work. but you wont be able to see the beams with out smoke or fog. the lasers are definitely strong enough to travel the 2 0r 3 feet to hit the according photodiode.

now if you want a visually stunning laser harp then yes you will need a green laser or a 445nm laser with good optics.

 

[polonos13]

No, they are too weak. Now if they were 532nm and of the same power you could see the beam in the dark.

That will be a combination of the mw and nm. mw is the output of the laser, the bigger that number the brighter it is. nm is the wavelength of the laser. The closer the laser is to ~550nm the brighter It will be because the human eye is most sensitive to that wavelength. To be safe I would use 5mw 532nm ir filtered modules

As i understand ,to be a laser beam visible by the eye must have the smallest wavelength.For example a laser module 5mw with wavelength 650nm is not so visible as a laser module 5mw with wavelenth 600nm.Correct ??
I found one site to order the modules but the product that proposed me isn't good now that you've enlightened me.
That was the product :
http://www.egismos.com/support/laser module/S93650v3.pdf
and the proper photosensor
http://www.egismos.com/support/photo sensor/PD-RGB.pdf

What laser module should i use in your opinions (how many mw ,what wavelenght).
Can you suggest me any e-shop to order the laser modules that i need plus the proper photosensors for the modules.

Thanks again !

 

[udanis]

The color closest to 550nm is be the brightest. 405 will be dimmer than 532 given the same power.

 

[polonos13]

The color closest to 550nm is be the brightest. 405 will be dimmer than 532 given the same power.

Pffff....i m very comfused.
So thai isn't correct ?

"As i understand ,to be a laser beam visible by the eye must have the smallest wavelength.For example a laser module 5mw with wavelength 650nm is not so visible as a laser module 5mw with wavelenth 600nm."

Also :
What laser module should i use in your opinion (how many mw ,what wavelenght).
Can you suggest me any e-shop to order the laser modules that i need plus the proper photosensors for the modules.

 

[Zeroignite]

This might be helpful. x-axis is wavelength in nm, y-axis is perceived brightness for a given power. Your eye will see green light as brightest, with sensitivity fading off in either direction. Wavelengths shorter than 400nm or longer than 700nm are pretty much invisible. Also see The Wikipedia article on Color Vision

 

[KGB_Productions]

If you really want to make a harp head over to PL laser Harp V2 open and free

 

[udanis]

Pffff....i m very comfused.
So thai isn't correct ?


Also :
What laser module should i use in your opinion (how many mw ,what wavelenght).
Can you suggest me any e-shop to order the laser modules that i need plus the proper photosensors for the modules.

You weren't correct there.

This would make an awesome module: Green laser module 50mW For custom build or lab [OLGLM50] - $26.99 : Welcome to O-Like.com, Your source for laser products
You would have a beam with out the need of smoke/fog, and with smoke or fog it would be very nice.

 

[polonos13]

udanis thanks !!
I've just want to get opinions from some others about produts and prices.Also if it is easy i want to propose me and suitables laser diodes or photoresistors for the laser modules so that could have a complete image of the things i need.
Udanis for the laser module that you proposed me are these photoresistors good ?
200V FW200 - -
300V FW300 - -
Can you propose me suitables laser diodes/photoresistors for the laser module that you showed me.