Now I managed to get a blue laser diode with 1W output and wavelength of 445nm and 5.6 mm TO18 housing and optics for my powerfull blue homemade laser.
This diode has a deep blue light, unlike diodes from blu-ray (BD-ROM, BD-R, BD-RE), which have a wavelength of 405nm and
almost invisible violet light (on the borderline of visible and ultraviolet light).
Power of the LD is many times higher than the diodes from a CD-RW and DVD-RW drives (burners).
Optics with a diode quickly warms up. The diode is no longer the 10-20s too warm. I've found that the longer the operation will need better cooling.
I mounted the optics on a big aluminium heatsink.
Optics enables precise laser focusing by screwing lens in the "worm" with a fine thread.
You can focus either to close point or to the parallel beam. Diode can be powered either through resistance of controllable sources
(simple solution) or using the stabilizer with LM317T current source with voltage in the range 7-16V (better solution, as the current does not vary
with the input voltge).
LM317T circuit should be placed on the heatsink. The current is determined by resistor R1. Its value is determined by calculating R = 1.25 / I
The laser diode is connected to a protective circuit made up of four components (marked in blue in the diagram).
Capacitors and resistor protects against static charge diode, diode 1N4007 from the polarity reversal.
This protective circuot should be connected to the diode immediately after unpacking it from its protective antistatic bag and antistatic foam.
It should be removed from the diode.
When handling, modifying or replacing the power supply, never disconnect the bare diode, but the diode with protective circuit on it.
Seems, that the case is not connected with anything. It is necessary to connect the case to one of the poles, othervise the diode will be easily
destroyed by electrostatic charge. I connected the case to the cathode.
Connecting both terminals and case is also needed during soldering. Soldering time must be as short as possible.
The diode must never be soldered without heat sink (metal housing)! Caution - electrostatic sensitivity of the diodes
is much higher than in unipolar integrated circuits.
I tested the diode at current of 960 mA. The diode has a very bright blue light and a visible beam.
It burns the paper, plastics, fabrics, wood and so on. It is burning from a distance of many meters and the beam does not even have to be very well focused.
Paper or plastic burn decently with beam diameter of 3mm.
Setting the power above 1W (current over 960 mA) can significantly reduce the life or even lead to immediate destruction.
| Parameter | value | unit |
| Case diameter | 5.6 | mm |
| Wavelength | 445 | nm |
| Nominal power output | 1000 | mW |
| Nominal current | 960 | mA |
| Maximal current | 1400 | mA |
| Threshold current | 200 | mA |
| Voltage drop at nominal I | 4.45 | V |
| Differential efficiency | 1.36 | mW/mA |
| Max. working temperature | 55 | °C |
| Lifetime | 20 000 | h |
| Lifetime in dude's hands :) | 1 | ns |
