Optical Modulation of a Laser Pointer or Diode Laser Module

The typical red laser pointer is about 5 milliwatts, and a good one has a tight enough beam to actually hit the Moon—though it’d be spread out over a large fraction of the surface when it got there. The atmosphere would distort the beam a bit, and absorb some of it, but most of the light would make it.

For a laser pointer, the power rating – if it can be believed at all – is a maximum you might see with fresh batteries under the right conditions on a very good day, or possibly just the 5 mW maximum for Class IIIa (which is the most that is legal in the U.S.A. for a laserpen groen 100mw ). Obviously, the seller wants to impress you with the specs for their product and not all are being entirely honest or forthcoming. The actual power could be much less and may decrease rapidly as the batteries are drained.

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 laserpen 500mw groen . Exceed this rating for even a microsecond and your whimpy 3 mW output may be boosted to precisely 0.0 mW. 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.

If you still insist on experimenting, be aware that while this appears to be safe for the laser diode, there is no way of knowing for sure without tests. There could be funny resonances in the driver that will blow your laser diode at certain frequencies 200mw laserpen groen ! And, if the effect is due to lasing instability, the regulator may attempt to boost the current to compensate resulting in possible overheating of the laser diode, driver, or both.

The most powerful laser on Earth is the confinement beam at the National Ignition Facility, a fusion research laboratory. It’s an ultraviolet laser with an output of 500 terawatts. However, it only fires in single pulses lasting a few nanoseconds, so the total energy delivered is about equivalent to a quarter-cup of gasoline.