Tuesday, July 19, 2011

QPM 35 years old

In the Monday Planary session, Professor Martin Fejer decided to give a history of the quasi-phase matching, instead of the “current topics” as he planned. He said while he was researching the topic---history of QPM, he found many things “surprise me” so “might be interesting to you.”

The history was fancinating. Especially I found that a research area can start so “fast” ----1961 SHG was demonstrated, 1962 the paper on birefringent phase matching was published-----yet takes so many years to develop and can continue for many years more.

QPM was first used by A. Szillagyi in 1976. Now there are new topics such as aperiodic QPM gratings. I find these two topics in the Monday morning sessison very interesting; slant quasi phase matching, which has the possibility of developing high power lasers, and fabrication of a new walk off compensationg BBO periodic structure using the room-temperature bonding technique, which generates twice the SH UV power of a bulk BBO with the same length.