Making your own optics...

[IsaacHayes]

AilSnail: you need air space between the dome and optic. Other wise the light won't bend properly, and will just scatter throughout the optic. Now perhaps one could devise a different optic that worked differently than the traditional ones and it would be molded/epoxied into the dome of the emitter, but it would have to be of a different design..

 

[chalo]

Right. Refractive optics all work based on the difference in index of refraction between dissimilar transparent media. Acrylic, glass, quartz, MgF, or other lens materials would have to be of a different shape if they were dealing with an optic-to-epoxy boundary rather than an optic-to-air boundary.

That's why NX-05 and Fraen optics don't work well if they are dirty on the backside; they depend on the acrylic-to-air boundary instead of, say, acrylic-to-grease-to-air.

Chalo Colina

 

[AilSnail]

I don't know what you mean by "traditional". The high dome appears to have the undesireable effect of enlarging the die as viewed from the outside.
This I assume is dependent of the difference in refractive index between air and epoxy.

Parabola is parabola and whether tir or metalised primary mirror it reflects the same way so a parabola could be used i assume. From what I hear you loose 4% light for each interface so for a regular optic that would be dome to air to optic to air to lens to air, or five interfaces not counting the semiconductor/phosphor stuff etc.

if one managed to mold the dome into an optic of similar refractive properties i would imagine that the interface dome-optic would vanish. if then a glass lens was laminated on top there would be only optic to glass to air, two interfaces. I don't know if a durable lens could be found that would eliminate the interface between it and the optic.
I don't know if AR coat can be applied between two solid surfaces either.

 

[IsaacHayes]

Take for example, an ArcAAA. You probably have one right? Anyways, the lens on the led focuses the light. Now, place it in a sinkfull of water. This is the same as if the led was full of epoxy. Notice how the beam is gone. That's because the led lens no longer has any refraction because it's all encased in water. Same thing would happen with an optic. Unless you designed it like perhaps a big 5mm led len. It would probaly be round and stick out on the end...

 

[AilSnail]

well these are luxeons and they have hemispheric non-focusing optic hence "lambertian" if i am not mistaken.

There is a difference between refraction in the optic and reflection. The reflection (TIR, total internal reflection) can be much more effective than most if not all normal mirrors (you can see it in aquariums). However the light must hit the surface below a certain shallow angle for it to reflect, otherwise it will refract to the other medium.

 

[PhotonFanatic]

Does anyone have jarhead's e-mail address that they could PM to me?

I'd like to ask him some questions on his project. Thanks.

 

[RussH]

oeo2oo, it's in his profile - click on his name above

 

[IsaacHayes]

AilSnail I totally agree with what your saying, and it's possible, but not with the current shaped optics.. Unless you want to try it with something like an NX05 and some optical epoxy and prove everyone wrong... /ubbthreads/images/graemlins/smile.gif

The emiter is lambertain yes, but the "nipple" on the bottom of the optic must remain, as it catches and helps focus the light. If you mold the emitter dome into it, you remove the focusing properties of the bottom of the optic, not of the emitter. You'd just have a cone shapped lens on the luxeon, probably would act like a SE in a way then...

 

[AilSnail]

the nx05 seems to work like a mcflood with a refracting "nipple" in the center (aspheric?).

The LP is more like a parabola it seems.

If anything I would try it with a parabolic but I feel that the angle could be too steep at the bottom and let light through there.

 

[NewBie]

Does anyone have jarhead's e-mail address that they could PM to me?

I'd like to ask him some questions on his project. Thanks.

PhotonFanatic,

Well, a little time has elapsed, and I just now noticed your post.

:wow:

Just PM me here on cpf, I'd be more than glad to tell you what I remember.