Two-wave mixing in reflection holograms in photorefractivematerials

The intensity and phase of two counterpropagating optical beams in a photorefractive material are investigated both numerically and by using an approximate analytical theory. It is shown that in the reflection regime they are two situations where coupling between the beams may be spatially dependent; in the case of nearly degenerate two-wave mixing, and when a photocurrent is present. In these situations, previously obtained results may need significant correction     

Forces of Change: Ten Trends that Will Impact the Internet Over the Next Five Years

Regardless of how organizations measure Internet growth and usage, it is certain that the forces of change that affect the Internet will continue to evolve. in evaluating the economics of competing technologies and determining how organizations can get a return on their technology investments, this article reviews ten technology and consumption trends on the Internet. They are (1) multiple bandwidth delivery, (2) linguistic and cultural diversity, (3) privacy, (4) laws, (5) restricting access, (6) taxation of Internet commerce, (7) information age law enforcement requirements, (8) surviving on a crowded Web, (9) new sources of competition, and (10) information warfare and economic terrorism.     

Linear resonator in photorefractive BSO with two pump beams

A linear resonator using a new amplification mechanism in BSO is reported. The gain can be optimised for a particular frequency detuning of one pump beam