I tried to inscribe the LPG into fibers. At now I'm trying to achieve something, with no measurement. I found it is quite difficult to find proper combination of arc power, arc time and weight (strain) on fiber. However I got some partial results, looking actually quite good.

The photo of this 125um thin fiber was being shot with my Canon PowerShot SX150 IS with no special optics. Nice job for this cheap camera. You can clearly see the places at the end of fiber, periodically thinner than the rest of the untouched fiber - this should be the parts, where fiber and cladding modes meet and do a phase cancellation, as explained before.
However, this fiber broke during the inscribing, as well as few others. I have to fiddle with power a little more.