Small “dot” next to laser spot

Not sure what the term for this is or even if it’s been mentioned before to search on it but I have one of those green Radio Shack lasers that has developed a small little dot next to the spot where the beam shines. It looks like it could be a blemish or dirt but no amount of compressed air or attempts to clean it with lens cleaner, q-tips, etc. get rid of it. Brand new the beam was perfect and this happened to another red laser I had as well and was unable to clear up.

Is there any way to get rid of this?

I'm guessing that this is normal deterioration of the laser components. When brand new you get a perfect little dot which degrades over time.

It could also be that a small bit of the laser beam is hitting the side of the laser host and reflecting, so you get a mini dot next to the main dot

If the beam is hitting the side of the laser host I don't know what would cause this other than just carrying the device around. Looking in the housing I can't see anything obvious like a stray particle or scratch. The other laser this happened to I could get to the lens and even after careful cleaning that stray artifact little dot wouldn't go away.

hwang21 said:

It could also be that a small bit of the laser beam is hitting the side of the laser host and reflecting, so you get a mini dot next to the main dot

Click to expand...

Could be this. Also check your lens for anything and make sure it is in place.

does it look something like this?

If so, it just means your laser has "mode hopped" to TEM01- or "transverse electromagnetic mode 01". Normally, manufacturers try to stabilize the DPSS (diode pumped solid state) lasers so that they run in TEM00, which is a perfect round dot. Your little greenie is probably running in a different transverse mode, due to being poorly put together with cheap materials, as are 99% of the chinese lasers out there (yes, yours was made in china). It is not "deterioration of the laser components" as one person said- you would have had to have a lens or crystal deteriorate, which doesn't happen unless the laser is dropped, damaged, etc. So you either have just a typical poorly made laser, or something shifted inside causing a bit of reflection. Can you take a picture of the output? I have seen a few different lasers of mine in TEM01, ranging from a barely distinguishable double oval, to 2 near completely separated dots.

The little extra dot is close to the main beam point, like the one in your picture, but it is very tiny, just big enough to be noticeable. The same size scale ratio example of a man hole cover with a dime next to it, the man hole cover representing the main beam dot. I'll try and get a picture.

Here's a picture of the tiny extra dot. Its roughly in the 6 o'clock position really close to the main beam dot.

Davis said:

Here's a picture of the tiny extra dot. Its roughly in the 6 o'clock position really close to the main beam dot.

Click to expand...

looks like an internal reflection. could be from in the laser host, also possible that it is from one of the internal optical surfaces. Have you dropped or bumped it into anything? its possible one of the surfaces is just ever so slightly out of line.

I carry it in a pocket and thought it was accumulated dust or something. Maybe banging against something else in the pocket, keys, change, etc.? I chalked it up to poor quality or cheap parts. The same thing happened with a red RS laser I had years ago.

All of my Radio Shack lasers have done this. I, too, believe it is due to poorly made optics/poor alignment of components. There isn't really a good way that I know of to fix it. Just stay away from $30 radio Shack lasers, which are, in my opinion, inferior even to the cheapest eBay pens (which typically go for 1/3 or less of the price).

At a distance the extra little dot isn't noticeable but the fact that the extra dot is there is somewhat annoying. I can live with it. My next laser might be a better quality yellow laser but I still need to do some research as to beam viability, range, cost, vendor, etc.