New oclaro 700mw diode

[badger1666]

Anyone tried it yet ?

I got the new diode today from dtr ,swapped it out for one of the p73's
I was using , fired it up , and it looks like its going to be worse then the p73 for divergence
It does have a much cleaner beam though barely any wings or crap around the beam
Just a shame i cant get the divergence down. With daves mount 2mm fl lens 3x cylinder lens set
Best i can get is 1.4 mrad
Will be interesting to see if it can be improved with a different lens combo

[planters]

Can you give the near and far field beam dimensions and the baseline distance to the far field spot as well?

[badger1666]

i only tried over a short distance of 3.5m after seeing how bad it was did not bother doing it over larger distance
5mm near field , 10mm at 3.5m i make it 1.42mrad ,did the same with my p73 ,5mm nearfield 9mm at 3.5m 1.1mrad

[planters]

Wow! That's not good. I am trying to recall the dimensions of a dual, P73 module beam that I aligned for the projector in the video I made with the EMS 8000 scanner. The beam fit the 8.6mm minor dimension "X" mirror @ a 45 degree AOI with enough to spare to allow scanning +/- 10 degrees without vignetting. I measured the beam with a scale @ almost exactly square @ 5mm. I will retake the beam measurements tomorrow night, but I believe the rectangular far field beam was 4mm x 8mm @ 11.7M. But, I will recheck this.

[kecked]

opsl and fiber are still the only games in town for good high power red

[norty303]

and it looks like its going to be worse then the p73 for divergence

This is interesting, because it looks to be the same from DTR's tests against the G71/P73

I wonder what is different about it that you should be seeing these results?

[badger1666]

It maybe the diode I have that's not great ?? It might be down to being first batch and they are not all equal ??
I must say the slow axis is way better than the p73. And the beam quality is great compared to p73, I did notice that the uncorrected beam was not equally lit all the way across means I may have got one with a knackered facet which could be what's causing bad divergence, I will wait to see what someone else comes up with before getting anymore or not.

[LaNeK779]

is there any chance that we have gotten the emitter measurements wrong?

the spot is just a collimated "view" of the emitter, and badger has no reason to doubt his eyes.

[planters]

the spot is just a collimated "view" of the emitter, and badger has no reason to doubt his eyes.

This is not strictly true. This assumes the cavity is plano-plano (it is) and the gain region fills the cavity (I'm not sure if this is always true), but it also assumes the exit facet is essentially a perfectly flat surface. If there is optical power to this optical surface (this can be higher order)this can produce produce aberrations and divergence. Also, the gain medium may be inhomogeneous, especially with the intense thermal loading during operation. The common mode of operation of these diodes is multimode and the mode pattern is usually a serious of stripes that are parallel to the junction. This suggests the light path within the junction is not homogenous and likely involves reflections/refractions independent of the facet surfaces.

[Bbe]

Quite true, divergence varies depending on the optical power and chip temperature in a same diode. When measuring the divergence would be nice to specify these inputs.