Sanwu challenger 800mw strange beam

[BobMc]

Don't think I've ever seen nor heard of single mode diodes mode hopping. That is mostly a gas and DPSS thing. Unfortunately that does look led'd. It is when the die takes damage (these are being pushed hard) and the output loses coherence. When this happens, the output drops drastically and it will no longer focus properly. If it were the diode window, rolling the laser while on should cause a change in output as it rolls. These 405's are very well known to die for seemingly no reason at all. If anyone has ever had a diode mode hop, please say so.

Yea, this was one of those times I was hoping I was wrong but fearing I was right. . Thanks for a better description of what happens to a diode it goes "led". Hopefully it is still under warranty and Podo can do something. It a major bummer when a unit goes belly up. Sad day for sure.

 

[ElectricPlasma]

Don't think I've ever seen nor heard of single mode diodes mode hopping. That is mostly a gas and DPSS thing. Unfortunately that does look led'd. It is when the die takes damage (these are being pushed hard) and the output loses coherence. When this happens, the output drops drastically and it will no longer focus properly. If it were the diode window, rolling the laser while on should cause a change in output as it rolls. These 405's are very well known to die for seemingly no reason at all. If anyone has ever had a diode mode hop, please say so.

I couldn't tell you for sure if this is mode hopping, but a month or so ago I was using a friend's presentation pointer and noticed this, I took a picture because it looked like an odd beam/output. This is zoomed in on it, it's just a low power red:

it's pretty washed out though

 

[trussmonkey25]

Your focusing lens has moved too far in. Sometimes it creeps in as you adjust the variable focus. Thread the diode assembly back up a little and put it back together. All my Sandusky do that on occasion. Also. Check out some of the lens cleaning tips if you smudged any of the optics. Don't fire it if you think it's dirty.

 

[Radim]

Don't think I've ever seen nor heard of single mode diodes mode hopping. That is mostly a gas and DPSS thing. Unfortunately that does look led'd. It is when the die takes damage (these are being pushed hard) and the output loses coherence. When this happens, the output drops drastically and it will no longer focus properly. If it were the diode window, rolling the laser while on should cause a change in output as it rolls. These 405's are very well known to die for seemingly no reason at all. If anyone has ever had a diode mode hop, please say so.

As diodes are usually multimode at higher powers (except 405 nm which is usualy single mode), there might be modes hopping. My 520 nm is like TEM33 or something. My 635 nm mode hopps during power level change (different multimode pattern at low and high power).

 

[steve001]

I have a sanwu 800 mw challenger - have had it for a few weeks. Looked great at first but the beam recently weakened (at all mode settings) and there are two strange artifacts. First, the "dot" is no longer a dot. It is like a dot surrounded by two crescents - there are three separate "lobes" of light. Additionally, there is a large dimmer circular halo surrounding the dot that wasn't there before. This effect is not due to the lens as I have tried both a G2 and G7 lens and the effect is still there. Overall, it is about half as bright as my 300mw 405nm challenger.

Any ideas what is going on?

As others have pointed out it died. Now it is a led.
You had if for a few weeks it is under warranty.
So you know lenses don't create modes, modes are created by the diode.

 

[paul1598419]

I couldn't tell you for sure if this is mode hopping, but a month or so ago I was using a friend's presentation pointer and noticed this, I took a picture because it looked like an odd beam/output. This is zoomed in on it, it's just a low power red:

it's pretty washed out though

I have a cheap 532nm laser pointer that does this at the first second it is turned on. Then the two collapse into one beam. For mine it is mode hopping from a cold start. Probably the same for yours.