- Jul 10, 2015
Look at their VIS 0 lenses. I recall the reflectance per surface will be less than 1.25% and can be a low as .4% per surface. Look at their listings for AR coated pcv and pcx lenses you'll see a pricing sweet spot.The three element gave me the tightest spot out of the following collimators that I have tried:
DTR G2 (Won't screw far enough into my OPT TO-5 brass diode housing to focus)
DTR three element
OPT three element
OPT single lens
Sanwu G7 (hasn't arrived yet, will test when it does)
A pair of 25mm lenses from Edmund to create a 4x expander is only $69. With this option, I know exactly what I am getting with all the datasheets they provide.. The lenses have 1.25% reflectance at 520nm, MgF2 coating, etc. The expander from Sanwu is 60$ and has no data on anything. Who knows what the surface quality, coating, reflectance, max power density, etc. is?
I don't think so. All of the schematics I've seen for Galilean beam expanders mostly use two lenses. One a negative pcv, the other a positive pcx. Occasionally you'll see a beam expander with two lenses cemented together or spaced very close together. What's your application for the beam expander? One thing to keep in mind is to make sure the pcx lens has a diameter large enough so it does not truncate the sides of the beam as the beam passes through it.I agree, 30% wasted power is unacceptable. Once I'm finished with the corrective optics, I'd like to examine the initial collimator optics. If I wanted to build a collimator from scratch, I assume I'd need to look into aspheric lenses, correct?