Hi Steve, thanks for the quick reply.
I may have expressed myself a little vague. I am not after beam profiling or measuring intensities. I´m working with stacks of single emitter red diodes (mainly Ushio 170mW, Sharp 180mW in 638nm and Mitsu 836 in 658nm if mixed red is desired) as well as the 1W 520nm and 2W 445nm TO9 diodes. Each one in its own diode cup with a lens barrel in front. When I have for example 24 of them in a single plate (in 2 groups of 12 diodes) I go near the collimation point with each lens, pointing on a black wall. Then I switch to my mirror 15m away that bounces the beam back to a sheet of paper right in front of me. Then I finally collimate each lens of the array to the best image of the emitter. After all diodes are collimated it goes on with knife edging and so forth.
As you can imagine, the beams do not exit the array all parallel, but they give a "shotgun pattern" 15m away, lets say 80x30cm. As my bouncing mirror is only 10x10cm, there´s a lot of pointing and its hard to keep the diode i`m just collimating onto the mirror. It works OK, but there should be a more elegant (and thus faster) way to accomplish perfect collimation. And yes, i do projector aligning and module building on a daily basis and for a living
My Idea was to kind of simulate those 20 or 25m of space to be able to collimate the beam to infinity. And via some attenuators and a monitor, so I won´t get blind some day. Those green 1W diodes are some nasty bright bitches, even with my welder´s goggles on...
Hallo Viktor,
I actually tried the zig zag method some years ago, but my surface mirrors are not good (=flat) enough obviously. Every reflection deforms the beam just a little bit, and that adds up to an unusable, distorted image.
To give you guys an idea what I do: This is a red module (never mind the shot diodes) I got back for repair. You see the arrangement of the diodes in the block. That´s only the half of a 6W 638nm module, but equipped only to 5 as per request of the customer. So, when i have to build a couple of these babys some time saving (and even better beam quality?) would be much appreciated.