Repair of Diode Laser Pointers

Where there is no external focus adjustment, it may be possible to remove the front bezel and then access an internal focus ring. With luck, it can be turned with a flat blade screwdriver or other suitable tool to tweak for best focus. Take care not to scratch the soft plastic lens. However, it may be necessary to remove a bit of glue locking it in place. If the entire lens assembly is glued - no threaded barrel - adjustment may not be possible.

While it might be feasible to increase the current to the laser diode, unless you know its specifications AND have an accurate laser power meter (mucho $$$), there is no way of knowing when to quit. Above their rated maximum optical power, laser diodes turn into DELDs (Dark Emitting Laser Diodes) or expensive LEDs. Exceed this rating for even a microsecond and your whimpy 3 mW output may be boosted to precisely 0.0 mW 100mw blauw violet lasermodule . This is called Catastrophic Optical Damage (COD) to the microscopic end-facets of the laser diode. There can be also be thermal runaway problems or a combination of both of these depending on design - or lack thereof. However, if you have a bag of these gadgets and are willing to blow a few.

So, if even 5 mW of green isn't bright enough, the optimal solution would be to control the ambient illumination by putting a dimmer on the Sun. :) If this isn't an affordable option, the best that can be done is to use a screen or whatever that is a light color and has a diffuse surface, and orient it to avoid direct Sunlight. Unfortunately, if there is no way to control any of this as would be the case with use by an outdoor tour guide 250mW lasermodule rood , there are no good solutions. Even the best laser pointers have a divergence no better than about 1 milliradian (1 part in 1,000) so the power density of a 5 mW green spot projected on a surface more than a few meters away drops well below that of the 0.5 to 1 mW per square millimeter of Sunlight. Even the pure green color of the laser pointer will be quickly overwhelmed by the ambient illumination.

The following discussion resulted from the claim (mine and others) that reflecting the output of a laser pointer or diode laser module from a mirror might result in a decrease in output if it had optical feedback for power regulation. On one laser pointer I have, there is absolutely no effect rode lasermodule 50mw . On another, output power drops by at least 50 percent. My assumption was that it was the light reflected back and falling on the monitor photodiode that caused the effect and not some weird interference to the lasing process. But given what is described below, I'll concede that in many cases, it may indeed be the latter.

Lens tissue is best, Q-tips (cotton swabs) will work. They should be wet but not dripping. Be gentle - the plastic (probably) or glass and particularly the anti-reflection coating on lens is soft. Wipe in one direction only - do not rub. Also, do not dip the tissue or swab back into the bottle of alcohol after cleaning the optics as this may contaminate it.