OK, so I've been playing with my lasers for a while, and burning stuff got old pretty quickly (and the wife doesn't appreciate the stink and the scorch marks around the room either). So I want to try some interesting experiments with lasers, and one of the things that always fascinated me is holography.
I've had a look at all the discussions here (though holography doesn't seem to be a major interest around here) and I've studied a lot of theory.
So now I'm looking for a simple red diode with the following characteristics:
1) Must be able to have an almost infinite duty cycle (it must be able to be left on for many minutes at least);
2) Must be single-mode (no mode hopping, which would ruin any exposure)
3) Decent coherence length (I'd say at least 30 cm, preferably more)
4) Must be significantly over 5mW, but not extra powerful (it shouldn't burn the object being illuminated, and shouldn't be too dangerous for the eyes, especially considering that it wouldn't be focused at all).
I know that for 1) it's more a matter of the heatsink/cooling, but I suppose there are diodes better suited than others.
If I got an inexpensive LPC 826, could I drive it to a very low current until it emits about 50mW? Where is its low mW threshold?
I've also seen several pre-built modules in Odic's shop; these would be convenient because they include the driver. Have you ever tried any of them, and do they meet my needs above?
In general, could I just buy a higher powered module and "pot-mod" it to lower its power, to obtain better duty cycle / "single-mode-ness" / coherence length?
Also, is it possible to find / make a cheap interferometer, to see the "fringes" to estimate the suitability of a laser and setup?
Thanks
Cristian
I've had a look at all the discussions here (though holography doesn't seem to be a major interest around here) and I've studied a lot of theory.
So now I'm looking for a simple red diode with the following characteristics:
1) Must be able to have an almost infinite duty cycle (it must be able to be left on for many minutes at least);
2) Must be single-mode (no mode hopping, which would ruin any exposure)
3) Decent coherence length (I'd say at least 30 cm, preferably more)
4) Must be significantly over 5mW, but not extra powerful (it shouldn't burn the object being illuminated, and shouldn't be too dangerous for the eyes, especially considering that it wouldn't be focused at all).
I know that for 1) it's more a matter of the heatsink/cooling, but I suppose there are diodes better suited than others.
If I got an inexpensive LPC 826, could I drive it to a very low current until it emits about 50mW? Where is its low mW threshold?
I've also seen several pre-built modules in Odic's shop; these would be convenient because they include the driver. Have you ever tried any of them, and do they meet my needs above?
In general, could I just buy a higher powered module and "pot-mod" it to lower its power, to obtain better duty cycle / "single-mode-ness" / coherence length?
Also, is it possible to find / make a cheap interferometer, to see the "fringes" to estimate the suitability of a laser and setup?
Thanks
Cristian