No abstract

We report on a lithographic technique that uses self-assembled monolayers ͑SAMs͒ as a resist to fabricate patterned, chemically functionalized surfaces. Large area line, square, and triangular patterns with a periodicity of 532 nm were generated exposing SAMs of hydrophobic or hydrophilic alkanethiolates to an ultraviolet laser interference pattern at 193 nm for only a few minutes ͑corresponding to ϳ16 J/cm 2 ͒ followed by the immersion into an alternating thiol. Patterned films of CaCO 3 , Zn͑OH͒ 2 , and polymers were directly deposited on these templates. Using substrates patterned with oppositely charged SAMs, large periodic arrays of charged colloids were fabricated.

This work is meant to provide a review of different multiplexing topologies employing distributed erbium-doped fiber and Raman amplification to solve the problem of powerloss compensation in fiber-optic sensor (FOS) networks. This is a key parameter in large multiplexing networks, particularly when employing intensity-modulated sensors. These topologies are studied both theoretically and experimentally, and a comparative analysis is carried out between them. The main parameters considered in the analysis are power budget, optical signal-tonoise ratios, scalability and architecture complexity.Comparison of the measured optical spectrum of amplified single and double bus networks for sensor multiplexing.

An amplitude-phase-conversion self-referencing technique for intensity-modulated photonic sensors that uses two different-wavelength fiber Bragg gratings is presented. With this technique, the system response has been demonstrated to be almost unafffected by network power variations as high as 90% of the total power launched by the source. We prove the multiplexing capability of this type of self-referenced fiber sensor by wavelength-division multiplexing two of them in a star network. A tunable fused biconical wavelength-division multiplexer is used for sensor addressing at the detection block, providing both good isolation and low cross-talk values.

No abstract