All-Optical Buffer

Current communication networks rely heavily on high speed electronic routers that make them expensive and protocol dependent. A solution to this problem is to route packets in the optical domain using optical routers composed of state-of-the-art components such as wavelength converters and arrayed waveguide gratings. In this manner, a transparent, more capable and power efficient system can be achieved.

To implement optical routers, it is required to design optical memory to resolve packet contentions. In this research, a feedback optical buffer was built to analyze how electronics and optics can be interfaced to achieve optical memory. A field programmable gate array was used to control the switching mechanism inside the buffer and an arbitrary waveform generator was used to simulate the signals sent by the main processor of the optical router.

Using the field programmable gate array, the complexity of the buffer’s switching controls was hidden and a simple interface was implemented for the external device. This technique allowed the overall system to approach the behavior of optical random access memory.

The conclusion obtained from this study was that the particular feedback buffer architecture used proved to be flexible enough to achieve variable and relatively long storage times. However, bit-error-rate measurements determined that the quality of the signal decreased significantly with an increase in the number of circulations. Future research is required to design ways to decrease noise or completely regenerate the signal during each packet circulation.