Recently I managed to get a few if more powerful laser diodes. They have 1W power and wavelength 808nm.
This is a typical wavelength for green DPSS laser pumping. These LEDs are also used also for industrial and medical purposes or for illumination of
Power of those laser diodes is many times higher than the power of diodes from CD-RW and DVD-RW drives (burners).
First I tried plugging the diode in between heatsink fins. This proved to be insufficient. The diode is too warm after 10-20s.
I found that these diodes in close proximity can burn the black plastic or insulating tape even without optics. I also tried
beam focusing by lens held shaking hands :) but it is not an ideal solution. Then I attached the diode to the heatsink
from ATX supply. The diode has a much better thermal contact and is not overheating. I put the optics from the CD-ROM drive in front of the diode.
This can make better beam focus. I was afraid that the plastic lens will melt, but it did not happen.
The disadvantage is that the lens is difficult to set exactly on the axis of diode and so the beam is not very good focused.
I was also thinking about electromagnetic focusing using system from CD or DVD drive and focus using a potentiometer, but finally I did not try it.
I managed to get housings with glass lens that is designed for red diodes from about 600nm and infrared diodes with more than 800nm.
Diode diameter is 9mm, Case TO-5. The housings with optics allow precise focusing of laser by screwing the lens in the "worm" with a fine thread.
It can focus to near point as well as into parallel beam. Laser diodes can be powered by an adjustable power supply with resistance in series
(poor solution) or using a current source with LM317T, operated from the arbitrary voltage in the range of 7-16V (better solution).
LM317T circuit should be placed on the heatsink. The current is determined by resistor R1. Its value is determined by calculating formula R = 1.25 / I.
You can use those resistors or a combination of resistors:
3x 3R3 / 0,6 W parallel for 1136 mA,
2 0R51 / 1W in series for 1225 mA,
1x 1R / 2W for 1250 mA.
Class IV laser
Warning! Laser diodes from DVD-RW drive are emitting visible and invisible
laser radiation and they are extremely dangerous! Their light can permanently damage the eyes.
You must never look into the working diode even without the lens or point it on a reflective surface.
Laser beam can cause burns or fire. This is usually a Class IIIb laser. Everything you do at your own risk.
Note: The near-infrared light can be at very high intensities slightly visible, but if there is a situation that you already see
faint red light, in fact, you are looking at the extremely intensive light and risk eye injury!
Seemingly small brightness is due to a very low sensibility of the eye to this
wavelength. For this reason, infrared lasers are very dangerous. Sensitivity of cameras to infrared radiation is higher.
What is seen on photos below, can not be seen with the naked eye!
Schematic of stabilized current power supply for 1W laser diode and the simplest supply.
Pinouts of 1W 808nm Laser diode and LM317T (in TO220 case).
808 +/- 5
Voltage drop at nominal I
Max. operating temperature
Life time in lama's hands
Datasheet of the 1W 808nm laser diodes.
1000mW 808nm laser diodes in TO-5 can (9mm).
Inside the laser diode chip is seen with the four lead wires.
First laser diode test - to show how cooling should never look like :). For more than 10s it could not be used. Laser diode has almost no contact with heatsink.
Second test - here it's really heat sinking. The diode is mounted on a heat sink by base pad. It can be operated without problem for several minutes.
Outlets of diode through a hole in the heatsink.
Detail of laser diode mounting.
Test of the laser diode.
Lens from CD-ROM drive
Optics bolted to the radiator with a diode.
Laser optics for diode 9 mm with handle.
Disassembled laser optics
Laser head for screw lens.
The lens in the screw.
The laser diode in the head.
Assembled laser module.
The CD box with a hole burnt in it :).
Parallel laser beam.
Laser beam focused to a near point.
It can burn a wood. Inscriptions burned into the wooden board :).
Laser burning through four plastic plates in a row.
Video 1 - The first experiments with diode at 1000 mA.
It is powered via a resistor 3R9 / 10W from a adjustable power supply. Poor cooling (can be switched on only briefly).
Diode burns things with lens and also without the lens.
Video 2 - The LED on the metal plate from the ATX PSU heatsink, optics from CD-ROM.
Burning through the CD box and cutting it, cutting the duct tape and lights matches.
Video 3 - Laser with screw optics lights the same match 3 times. For the first time with a head, then 2x with no head (wood only).
Video 4 - Laser 1W 808nm cutting plastic bag at 1160mA.
Video 5 - cutting CD case, duct tape and burns holes into the box from CD (from the rear).
Video 6 - Burning letters into wood and cardboard.
Video 7 - Automatic laser pipe cutter :)
Not for lamas!
Power laser diodes are not really designed for lamas. When someone writes that I'm kidding, because he has the same diode, and the diode 1) is red and not infrared, and 2)
the diode is definitely not as powerfull and dangerous as I say, because it shines faintly, I almost
bang my head against the wall ...