Laser color for EDC

[Sarge]

I'm looking at picking up a couple of M&P Shield 2.0's with integrated laser. For Carry, purse, house use what is the consensus on laser color these days. Green or red?

[hitman_usmc]

Green wins for visibility every time. Though they can struggle in cold weather conditions. 

[caspian guy]

Green

[Hi-Power Jack]

I have a red ...   very nice in standard lighting, but completely washes out in direct sunlight   

 

I've read, here, that the green does NOT wash out in direct sunlight     

[Sarge]

I know green works better on the PCC’s for longer distances so stands to reason it should work better up close.

  Hadn’t heard about cold weather issues with green. What gives there I wonder?

[Chris Keen]

Green is a cooler color so it starts to congeal in cold temps. Unlike red which is a warmer color and is impervious to cold weather. 

[Hi-Power Jack]

Humor, Chris ?

[Sarge]

I found this

 

Greens are VERY temperature sensitive.

Red lasers are a single stage diode. The electricity goes in, and it lights up.

Greens are much more complicated. The electricity goes in, the infra red diode at a frequency of 808nm lights up, and because of all the jumps and stages it'll go through next, it's way more powerful than the output wattage you'll actually get in green at the end. 

The 808nm IR laser light then passes into a Nd:YVO4 (Neodymium, Yittrium, Vanadium, Oxygen...) crystal that absorbs the 808nm IR laser light, and re-lases in an even lower IR frequency of 1064nm IR light. It then passes into a second crystal, called the KTP (Potassium Titanyl Phosphate) which absorbs most of the 1064nm IR light and re-lases it in visible 532nm green laser light. Then an IR filter (assuming it's a quality laser built properly) cleans out any remaining 1064nm and 808nm IR laser light that may have leaked through. Then it's focused by the final objective lens.

The 808nm pump diode is often as high as 1/2Watt - 500mW in power to push through all the crystals and filters, and compensate for all the transition losses in efficiency etc. This also makes green lasers more prone to getting very warm because the extra wattage and inefficiency all comes out as waste heat. 

All these parts and steps make the green laser module very temperature sensitive. And the thermal expansion and contraction in the mounting assembly and the crystals themselves can greatly affect the efficiency, to the point it won't successfully lase through all the steps to produce green.

[bockerSV]

Kevin,

 

You can look into this further but what you described is the old school way of making a green laser. Most green laser sights for use on firearms are green directly from the diode, now.

 

These old models, in combinations with other problems, were very temperature sensitive. The newer way of doing things more closely follows the operating temperature range of red lasers.

 

Green lasers do burn through energy at a little faster rate but I would choose green any day. The human eye sees green easier than other colors in the light spectrum so, all things being equal, the green laser will appear quite a bit more visible. 

 

If you guys make it to any of the big firearms industry tradeshows, swing by the LaserMax booth and you can see a green vs. red side by side.

[Sarge]

6 minutes ago, bockerSV said:

Kevin,

 

You can look into this further but what you described is the old school way of making a green laser. Most green laser sights for use on firearms are green directly from the diode, now.

 

These old models, in combinations with other problems, were very temperature sensitive. The newer way of doing things more closely follows the operating temperature range of red lasers.

 

Green lasers do burn through energy at a little faster rate but I would choose green any day. The human eye sees green easier than other colors in the light spectrum so, all things being equal, the green laser will appear quite a bit more visible. 

 

If you guys make it to any of the big firearms industry tradeshows, swing by the LaserMax booth and you can see a green vs. red side by side.

Thanks! Yeah, I'm leaning towards green. And especially since S&W bought CTC it's literally almost a free upgrade to the basic gun relatively speaking.

[tattooo]

Green is great in daylight, red not so much.

[bockerSV]

57 minutes ago, Sarge said:

Thanks! Yeah, I'm leaning towards green. And especially since S&W bought CTC it's literally almost a free upgrade to the basic gun relatively speaking.

Yeah, the difference in pricing between the laser and non-laser version is minuscule. They did a good job with it, from what I have seen.