cheap green light source
cheap green light source
(OP)
Hi
Can any one suggest a cheap and portable monochromatic source for demonstrating Newton fringes ( or similar interference fringes ) . green light is ideal but a green laser is ruled out becuase of cost ( target under $40 ) . I could use a narrow band filter plus torch ( flashlight ) but it will not be efficient becuase it will lose a lot of light. Are there any narrow (ish) green light flashlights around LED or other? Hopefully available in the UK ? any other suggestions are welcome.
thank you in advance . Opticsman.
Can any one suggest a cheap and portable monochromatic source for demonstrating Newton fringes ( or similar interference fringes ) . green light is ideal but a green laser is ruled out becuase of cost ( target under $40 ) . I could use a narrow band filter plus torch ( flashlight ) but it will not be efficient becuase it will lose a lot of light. Are there any narrow (ish) green light flashlights around LED or other? Hopefully available in the UK ? any other suggestions are welcome.
thank you in advance . Opticsman.





RE: cheap green light source
Fluorescent bulbs have a narrowband green line - the 546 nm mercury line. Cover the bulb with an appropriate green filter (check theater lighting shops for "gels," Rosco being a likely find). You also need a diffuser, which you might also find at the theater lighting shop.
I've never tried this, but it might also work: Your CRT monitor's red phosphor is very narrowband. If you can fill the whole screen with pure red, it might make an excellent source for viewing newton's fringes.
CEV
RE: cheap green light source
RE: cheap green light source
I logged onto the forum to inquire about suggestions to collimate this light onto a 1.5 inch diameter sample. As bulb life increases, the light source weakens and the fringe contrast is not so good anymore. Otherwise, this source does the trick [recommended for viewing Brewster's and Newton's fringes]. In the printed Edmund Industrial Optics catalog, see facing page on "Using Optical Flats".
Michael Alderete
Mech Packaging Engineer
DRS Technologies-Sensors & Targeting Sys
Anaheim CA
RE: cheap green light source
What are you planning on doing with it?
since I work in the same area, you could call my office at x1006
TTFN