Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Does wave-length/color make a difference?

Mathewe

Member
Joined
Oct 3, 2021
Messages
51
Points
8
I've read that wave-length and color makes no difference in the potentials of a laser, it's all about power. Is this actually true?
Different colors are made from different wave-lengths. Do those long/short wave-lengths not act differently in the big picture of energy and potential?
Let's use fiber lasers as an example. I now have a brand new 8KW fiber laser in my metal shop. When looking into how fiber-lasers work, basically they seem to cram as many photon/energy 'thingies' into one strand of fiber, via multiple sources of emission, to concentrate the power (this is obviously the good ol' boy, 'red-neck' science definition). That being said, in a poor manner... wouldn't that 'also' mean that laser diodes with a shorter wave-length would be able to cram more energy 'thingies' into 'their' collimated beams than a diode producing a longer wave-length 'thingie'... which would take up more space, in the beam, than a shorter wave-length 'thingie'?
'Thingie'. That 'is' a scientific term, isn't it?
 





julianthedragon

Well-known member
Joined
Jun 3, 2020
Messages
369
Points
63
Wavelength does matter but not in the way people think. Power=power no matter the wavelength.

That said, beams of different wavelengths have different properties like:
- how much the light is absorbed, reflected, or passed through by certain materials
- how bright the wavelength appears to the human eye (relative to the 555nm green-yellow peak brightness)
- other special properties like 405nm's ability to make objects floresce and charge glow in the dark objects
- lots of special applied sciencey properties

Sidenote - It's also worth noting that among consumers, there can be notions that one wavelength is "stronger" than another due to the most widely available technology that produces that wavelength. A great example is how people think 405nm burns better but really it's just because most 405s on the market are made with single mode diodes that can focus to a very tiny round spot while a square shaped 445 beam needs more power to reach the same strength -- correct me if I'm wrong but going off my experience here
 
Last edited:
Joined
Sep 20, 2013
Messages
17,408
Points
113
The "thingies" you are talking about are called photons. And, yes, more photons can be in the beam of shorter wavelength lasers, but that really has nothing to do with a laser's power. Comparing the photons in a 1 watt 650nm laser to the photons in a 405nm laser you would find that the numbers of photons is not equal in both. Hope that helps.
 

Mathewe

Member
Joined
Oct 3, 2021
Messages
51
Points
8
Wavelength does matter but not in the way people think. Power=power no matter the wavelength.

That said, beams of different wavelengths have different properties like:
- how much the light is absorbed, reflected, or passed through by certain materials
- how bright the wavelength appears to the human eye (relative to the 555nm green-yellow peak brightness)
- other special properties like 405nm's ability to make objects floresce and charge glow in the dark objects
- lots of special applied sciencey properties

Sidenote - It's also worth noting that among consumers, there can be notions that one wavelength is "stronger" than another due to the most widely available technology that produces that wavelength. A great example is how people think 405nm burns better but really it's just because most 405s on the market are made with single mode diodes that can focus to a very tiny round spot while a square shaped 445 beam needs more power to reach the same strength -- correct me if I'm wrong but going off my experience here
I agree with you, especially on your 'side-note'! I too was bamboozled into the 405/450 stuff for power and burning... until I did a bit more digging and research. Power = power just as a pound = a pound. Lasers are just so new to me that I still do not yet understand the physics involved, but I will, given time. This laser thing started out as a whim, for an FX project that I have in mind, however. The deeper I dig into this, the more interested I become in the 'nuts and bolts' science, as well as other potentials and possibilities. There's something about lasers that is somehow pushing a lot of my curious buttons, despite the fact that I've yet to fire a single laser. Not sure where this 'whim' is going to take me, but I'm having great fun with the beginning of this journey, so far!!!
What's the deal with yellow and orange laser diodes? They seem to be quite limited in power and also not readily available. Just curious.
 

julianthedragon

Well-known member
Joined
Jun 3, 2020
Messages
369
Points
63
What's the deal with yellow and orange laser diodes? They seem to be quite limited in power and also not readily available. Just curious
Correct, yellow and orange diodes are definitely not readily available. The most common, and still exceptionally rare yellows on the market use 589nm DPSS modules which use technology based on pumping a series of crystals with a diode of another wavelength, in this case 808nm. The 808nm is converted to 1064nm and 1319nm and then summed to 589nm. This is the cheapest way to get it in a handheld. 532nm green lasers and 473nm blue DPSS use a similar process.

Beyond that, yellow and orange can be created with metal vapor, gas, more advanced DPSS techniques, and good old semiconductors but we're talking stationary lab lasers and thousands of dollars mostly for scientific research.

Here's a great resource to see all the availability of yellow/orange (and all of the visible wavelengths) put together by an LPF member:

Also see this ongoing project by a member who decided to build an orange lab laser by cooling down red laser diodes:

Lasers can be very fun and interesting and there's a ton to learn, good luck!
 

Sowee7

Active member
Joined
Feb 1, 2021
Messages
439
Points
43
Correct, yellow and orange diodes are definitely not readily available. The most common, and still exceptionally rare yellows on the market use 589nm DPSS modules which use technology based on pumping a series of crystals with a diode of another wavelength, in this case 808nm. The 808nm is converted to 1064nm and 1319nm and then summed to 589nm. This is the cheapest way to get it in a handheld. 532nm green lasers and 473nm blue DPSS use a similar process.

Beyond that, yellow and orange can be created with metal vapor, gas, more advanced DPSS techniques, and good old semiconductors but we're talking stationary lab lasers and thousands of dollars mostly for scientific research.

Here's a great resource to see all the availability of yellow/orange (and all of the visible wavelengths) put together by an LPF member:

Also see this ongoing project by a member who decided to build an orange lab laser by cooling down red laser diodes:

Lasers can be very fun and interesting and there's a ton to learn, good luck!
pure yellow diodes never existed, orange at 599-605 diodes existed some time ago in a lab and yellow-greed diodes at 560 and 565 were made for a few seconds in a lab (it burnt out after that) but no yellow diodes have ever been made commercially. also they missed a few wavelengths like 588nm can be made with doubled OPSL (i have one)
 

Andratos95

New member
Joined
May 6, 2022
Messages
25
Points
1
I've read that wave-length and color makes no difference in the potentials of a laser, it's all about power. Is this actually true?
Different colors are made from different wave-lengths. Do those long/short wave-lengths not act differently in the big picture of energy and potential?
Let's use fiber lasers as an example. I now have a brand new 8KW fiber laser in my metal shop. When looking into how fiber-lasers work, basically they seem to cram as many photon/energy 'thingies' into one strand of fiber, via multiple sources of emission, to concentrate the power (this is obviously the good ol' boy, 'red-neck' science definition). That being said, in a poor manner... wouldn't that 'also' mean that laser diodes with a shorter wave-length would be able to cram more energy 'thingies' into 'their' collimated beams than a diode producing a longer wave-length 'thingie'... which would take up more space, in the beam, than a shorter wave-length 'thingie'?
'Thingie'. That 'is' a scientific term, isn't it?
Not sure that I understand the question fully but... Power is energy divided by time. Since the energy of a photon is E=hf, where h is Planck's constant and f=c/lambda is the frequency (lambda is the wavelength), if you have the same power in a red and a blue laser, this just means that the red laser is actually outputting many more photons, since each red photon carries much less energy than a blue one (so you need to send more per unit time to achieve the same power).
 




Top