What is the longest wavelength of laser light you have seen?

[zyxwv99]

780, 808, 980, 1064, 1342?

Sensitivity of the human eye when viewing ordinary objects illuminated by a standard lamp simulating northern daylight at midday at 45° N latitude.

scotopic (night) vision

nm sensitivity

380 0.000589
385 0.00111
390 0.00221
.
.
.
500 0.982
505 0.998
507 1.00
510 0.997
.
.
.
775 0.000000183
780 0.000000139
780 0.000000139

photopic (color) vision

nm sensitivity

360 0.00000392
365 0.00000697
370 0.0000124
.
.
.
550 0.99
555 1.00
560 0.99
.
.
.
815 0.00000129
820 0.000000911
825 0.000000642

Reported ranges (anecdotal) when viewing bright sources of monochromatic light:

300nm? - 1350nm?

 

[Sigurthr]

Confirmed actual laser light would be 848nm, <1mW. Shortest laser light is 405nm since I haven't been around any UV lasers. Now, as for non laser light... 313nm-940nm.

I'd love to test my true visual range with a full spectrum monochomator.

 

[mojo_1234]

Own a 980nm 1W diode - totally invisible for me - not like this faint red color of 808nm pump diodes.

 

[zyxwv99]

Thanks for the replies. Actually I'm curious about the range of vision in general with respect to wavelength. So far three different types of vision have been documented: photopic vision (cones), scotopic vision (rods), and mesotopic vision (both rods and cones in moderately dim light). However, it seem that there is a fourth type of vision: when the retina is bombarded by photons of wavelengths to which the rods and cones are just barely sensitive, but with few or no photons at more visible wavelengths.

Just doing a bit of searching, it looks as if 313nm and 940nm are both common wavelengths, so we have something there that might easily be corroborated. The info about 980nm is also useful, as we now know that either the human eye can't see that wavelength or the laser needs to be substantially more powerful than one watt.

I would like to see everyone's visual range tested with a full spectrum monochromator when they go to the eye doctor for an eye exam.

 

[Fiddy]

can see 808nm dot at 1.7W

 

[Atomicrox]

Nice thread, missed it until you posted on the UV flashlight thread

I've only seen from 405nm to 808nm due to lack of sources. I have a 365nm flashlight but it leaks so much visible light that I can't differentiate the UV. I'll order some IR wavelengths and report back when I get them!

 

[zyxwv99]

Great! Just be careful.

I was concerned when someone in this thread said they couldn't see the dot on a 1 W 980nm laser. It made me think how much eye damage it could do just trying to look at the dot. My guess is that you might not notice anything until you tried to read text. That's because we can't see the blind spots we already have in our eyes, so we might not see a burn dot in the center of the fovea (central part of the retina) until we try to read. Then we might realize that we can't read because we're only seeing the letters with the parts of the retina that have less visual acuity. I think the more diffuse the source, the safer.

Meanwhile, I'm going to start looking for affordable optical filters. For example, something that filters out everything above 365m, or below 780nm, 808nm, 945nm, and 908nm.

 

[Sigurthr]

Yes, anyone doing testing please use diffuse and divergent sources. Also keep in mind the limitations of your equipment; for a while I wondered why my spectroscope wasn't showing 365nm until I realized it uses a plastic grating! It wasn't film so I assumed it glass, but it is not!

 

[Photonz]

Ive seen 10600nm before but it's reaaaallly dim
just kidding

 

[Atomicrox]

Don't worry, I'll take care. I don't think looking at the dot of a 1W 980nm is that dangerous if you do it from a safe distance (3m) on a matte surface. But it might be more productive to look at a lower power (<10mW) from a smaller distance...

The problem with non-laser sources is that they aren't monochromatic. Let us know if you find some decent filters for a reasonable price!

 

[Sigurthr]

If you're using a non monochromatic source you need either a monochomator or a spectroscope and reference line since all you're doing is qualitative and not quantitative analysis.

I.e. a spectroscope + an eye safe reference wavelength near by the target wavelength allows you to look to see if you can detect the target based on an estimation of where it should show up in reference to the reference wavelength. You just have to be careful the reference doesn't wash out the target in intensity. With this method you can determine the presence of wavelengths not on the spectroscope scale. It isn't as good as using a monochomator, but a spectroscope for 400-NIR is only $10 (or a grating + a cardboard box).

 

[norbyx]

Well I managed to see a 808nm 300mw beam in a dark room with fog, the dot its quite visible to me, but to see the actual beam was a bit of a challenge, it is very very faint dark red.
As for the other side of the spectrum, well I don't have anything bellow a 100mw 405nm and that is just plain normal to see.

 

[Ears and Eggs]

I used to have a 500mW 808nm. In the dark the dot was very visible, but outside in daylight it was very hard to make out. Similar with the 7mW 405 I had. The 7mW 405 is very faintly visible to the far right in my avatar.

 

[Photonz]

it probably doesn't help that theres a 445nm right next to it

 

[Ears and Eggs]

it probably doesn't help that theres a 445nm right next to it

lol it was actually a 70mw 473. A ~1W 445 would have destroyed the shot.

The others are all 5mW.

 

[Photonz]

my bad and wow, thats a pretty nice shot of a 473nm!