Optical Network Integration Platform Based on Holographic Super- Dense WDM Filters; Conference paper

摘要

We have demonstrated the feasibility of realizing an Optical Network Integration Platform (ONIP) that would address the requirements of the Army's FCS and WIN-T programs. The breakthrough networking capabilities represented by this technology is in the ability to filter and multiplex extremely narrow optical channels, on the order of 10 GHz at bandwidths of 5 GHz each and the ability to increase significantly the number of channels that can be carried on a fiber or free space optical transmission facility. The ONIP is a generic, scalable networking device that accepts inputs from wired, wireless or free- space and fiber based communications networks. The design of the ONIP is based on the use of ultra-narrow band, thick holographic filters. Briefly, each filter can combine two optical channels, separated by a frequency as small as 10 GHz. At the input port of the ONIP, two optical frequencies are first combined using a single filter. This is followed by another filter, which combines the first two frequencies with a third frequency. By repeating this process, (N-1) gratings can be used to combine N optical frequencies, representing N input channels. On the output port, this process is reversed. We have successfully demonstrated a six-channel ONIP using thick holographic gratings. The frequencies of the lasers used for this ONIP were each close to 1550 nm, but all distinct from each other. The laser frequencies were controlled using a combination of current and temperature. We have demonstrated channel multiplexed optical communication with this ONIP, using direct modulations as well as wireless devices. The bandwidths of the gratings used for this proof-of principle system were not very narrow --- each about 50 GHz. However, very recently, we have succeeded in making much narrower gratings (close to 10 GHz).