I tried to put together a rudimentary heater setup.
As a heating element, I used the soldering iron tip heated up to ~800°C.
To make a reflector, I used the small basket which holds the cork of champains battles (see figure 1), and I covered it with alumnum foil. Of course, it cannot be really considered as a parabolic reflector, but it's something close (see figure 2).
Then, I put a ZnSe 1 inch lens, 3.5 inch FL (borrowed from TCS lab) right after the reflector, in order to collect as much as possible the radiation and focus it onto an image (figure 3). In principle, if the heat is collimated by the reflector, the lens should focus it in a pretty small image. Finally, in order to see the image, I put a screen and a small piece of packaging sponge (because it shouldn't diffuse too much), and I tried to see the projected pattern with a thermal camera (also borrowed from Aidan). However, putting the screen in the lens focal plane didn't really give a sharp image, maybe because the reflector is not exactly parabolic and the heater not in its focus. However, light is still focused on the focal plane, although the image appears still blurred. Perahps I should find a better material (with less dispersion) to project the thermal image onto. (figure 4)
Finally, I measured the transmitted power with a broadband power meter, which resulted to be around 10mW in the focal plane. |