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Best Blue Laser for most power/least divergence/maximum distance?

cncyana

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Jan 7, 2012
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I am looking at JetLasers PLE-Pro Blue handheld lasers:
1) 445nm: 1W - 5W with divergence at 2mRad and 3mm beam diameter for all power levels.
2) 465nm: 1.4W - 3.5W with divergence at 2mRad and 2.5mm beam diameter for all power levels.

1) Does this mean that for a particular wavelength they are using the same diode but at different driver power levels? Or is their description a generic one for simplicity's sake? I notice as a general rule as power increases, the divergence and beam diameter increases for a given focus - at least for 445nm?

2) Assuming (1) above is correct, this means higher power does not necessarily translate into higher beam intensity as the distance increases, say 1/4 mile distance or more?

Anyway, I am looking for a blue laser as the title says.

Thank you for your help.
 



paul1598419

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You won't get a good looking beam out of anything close to 5+ watts as the emitters of these diodes is huge when compared to the 2+ watt diodes. The higher the wavelength the more visible it will be for the same power level. So, they are using different diodes. Not changing the current level they are driven at. I am not familiar with these lasers, per se, but I am familiar with the laser diodes used.
 

Immo1282

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Yeah - for good divergence, I'd steer clear of most powerful 445nm ones. My blue convoy build uses a single mode PLT5 450B diode kicking out around 300mW and it's one of the tightest diode lasers I own. the most powerful 445nm diodes have generally poor divergence and a rectangular beam shape (often appears as two short parallel lines).

Alternatively, get yourself a good beam-expander, like the x3 one from Sanwu or the x10 one from JetLasers and attach it - that'll dramatically reduce your beam's divergence at the cost of a slightly wider beam diameter.
 

smallfreak

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If you need „long distance“ you certainly need a good beam expander. The divergence drops the same rate as the diameter gets expanded, so with a 10x expander you are down to 0.2 mrad which makes a big difference over long distances. So you might be far better off starting with lower power and good divergence and still have a much better power density on the far end.

Thes high power lasers are good for really short distances where you can get a tight focus to burn holes somewhere. Thats what the diodes are made for: Engraving, cutting, ...

If you need long range precision beams, diodes are not the best technology to start with, as the cavity is short and the spot quality is mediocre. Solid state Lasers do produce far better beam specs that can be carried forward by good optics to a target far away.

The US Army had investet BIG money in developing powerful long distance lasers — and finally failed. But they might have different requirements regarding „power“ and „maximum distance“ than you.
 

cncyana

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Jan 7, 2012
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ok, I am very thankful for everyone's insight. I guess I'll forget about spending big money on high power and go for lower power and spend the money saved on an expander.
 




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