Laser works
This beam due to its perfect symmetry can then be easily collimated (focused) using simple glass lenses. With a 1:1 construction, where the distance from the end of the fiber optic cable to the lens and the lens to the focal point are approximately the same, we then achieve a focus diameter that is somewhat larger than the diameter of the center of the fiber optic cable. By carefully adjusting the distances between the end of the cable, the lens, and the focal point, it is possible to obtain a point of focus that is somewhat smaller (how much depends on how homogeneous the beam is) than the diameter of the center of the fiber optic cable, however only by using high quality lenses.
DIY Factory
Driver electronics and control: The simplest and safest control method is to drive the diode using a constant current power supply with the maximum current set considerably below the maximum current for the diode, together with an appropriately sized radiator (and/or active cooling e.g. a Peltier effect cooler) such that the diode remains under 30째C even under continuous duty. For currents under 1 Amp it is possible to use a constant current power supply together with an LM317 with a power resistor that defines the maximum current. The circuit can be taken from the LM317 data sheet.
Dangers and Safety measures: When working with laser diodes with power over 5mW all observers must wear protective goggles to protect from damage or blinding caused by the laser beam. The easiest protection is achieved using an opaque housing around the construction. A webcam can be added to the enclosure to allow observation of the procedure. Using this method even normally invisible IR laser diode beam can be seen.
445nm-diode collimated - 1m
In the next edition of the RepRap Magazine I will show possible areas of application for these self-built laser diode modules as well as showing some practical applications. REPRAPMAGAZINE
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