Mine was numbing and my body was secretly trembling the whole time it was happening at the SEC Auditorium.

I just turned 21.  This was my first scientific presentation in a professional conference. Seldom will you see Bachelor students presenting their research during that time. (Heck, seldom will you see Bachelor students graduating in those years!)

The title of my talk was “Pump Beam Depletion via Inverse Ratio Two-Wave Mixing.”  It was long but then it was still incomplete.  The title should have been, “Pump Beam Depletion via Inverse Ratio Two-Wave Mixing in a BSO crystal.”  But then it would have been too long.  If I had to rewrite the title today it would be more appropriate as, “Beam Depletion with a Photorefractive crystal.” Short and sweet.

Mine from my Master's thesis

I was only 1/3 to blame for the title though, and I was not even the first author. You might want to guess who has the theatrical skills to come up with the title.  My lips are sealed. I was just the designated talker.

“The Photorefractive effect is a bulk phenomena in which the local index of refraction is modulated by the space charge field produced by spatially varying intensity of light.”  That’s how I started my talk after the usual introduction, “I am blah blah of the Laser Physics Group of the National Institute of Physics, UP Diliman. I am here to talk about <insert title here>.”

After that,  everything was forgettable. Were there questions? I think none. If there was, it’s either I forgot or I made a major major blunder and then I kept the memory somewhere inaccessible.

So what was the presentation about? In a gist, we studied the depletion of the pump beam when normally the gain in the signal beam is investigated.  The two beams (the pump and the signal beams) make an interference fringe in the crystal thereby, starting the photorefractive effect. An energy transfer happens from the pump beam to the signal beam.  The pump beam’s intensity is very very large compared to the signal beam’s intensity such that a small energy transfer from the pump beam is negligible yet would be a huge gain for the signal beam. The energy transfer is only in one direction relative to the beams’ positions. Therefore to look at the depletion, we inverted the ratio such that the intensity of the pump beam is very much smaller than the signal beam.  (Hence, the logic of  the ‘inverse ratio’ in the title.) We arrived at nothing close to ground breaking. It was I guess barely enough for a presentation.