Hi everyone. I am new to this forum, and I am new to lasers as well. So, sorry if my question is very basic.
I am trying to assemble a simple portable laser projector similar to the one described here: TinyProjector. Basically, lasers are shined at a rotating hexagonal cylinder with mirrors on each of the 6 faces. Then an Arduino pulses them at specified intervals to project separate pixels.
I initially used a lower power 5mW red lasers (each consuming <40mA), which worked fine. However, I wanted to make the projection brighter, so I obtained 5mW green lasers. However, I found that they don't turn on fast enough to project individual pixels. Basically, it takes some time for the laser to become visible. I require the lasers to switch at approximately 500us, which doesn't seem very extreme and I was hoping that the lasers would be able to handle it.
I suspected the driver being the problem, so I built a simple current limiter based on LM317 to be used instead of the driver. However, this did not make any difference.
As a remedy, I tried overdriving the lasers with almost twice as much voltage as they require (5.4V instead of 3V). This helped to make the individual projected pixels a little more legible. I also tried to not power down the lasers to 0V between pixels, and instead keep them constantly at ~2V (such that they don't produce any output, but do turn on faster when applied the full voltage). I feel that these are really naive solutions. I hope that someone will be able to point me in the right direction.
Thanks!
I am trying to assemble a simple portable laser projector similar to the one described here: TinyProjector. Basically, lasers are shined at a rotating hexagonal cylinder with mirrors on each of the 6 faces. Then an Arduino pulses them at specified intervals to project separate pixels.
I initially used a lower power 5mW red lasers (each consuming <40mA), which worked fine. However, I wanted to make the projection brighter, so I obtained 5mW green lasers. However, I found that they don't turn on fast enough to project individual pixels. Basically, it takes some time for the laser to become visible. I require the lasers to switch at approximately 500us, which doesn't seem very extreme and I was hoping that the lasers would be able to handle it.
I suspected the driver being the problem, so I built a simple current limiter based on LM317 to be used instead of the driver. However, this did not make any difference.
As a remedy, I tried overdriving the lasers with almost twice as much voltage as they require (5.4V instead of 3V). This helped to make the individual projected pixels a little more legible. I also tried to not power down the lasers to 0V between pixels, and instead keep them constantly at ~2V (such that they don't produce any output, but do turn on faster when applied the full voltage). I feel that these are really naive solutions. I hope that someone will be able to point me in the right direction.
Thanks!