Biomedical subjects

Steve Blair

Publications and source records attributed to Steve Blair.

3 recordsLinked to original sources

PubMed2003

Engineering the nonlinear phase shift.

We treat the nonlinear phase shift response in the weak perturbation limit as a linear digital filter that can be synthesized into the values of its poles and zeros and mapped onto an optical architecture. This procedure results in a significant enhancement in the nonlinear sensitivity with a response that is robust to frequency changes within the filter passband. A precompensation technique can be used to reduce distortions under strongly driven nonlinear operation to achieve a larger phase shift. We also show that nonlinear sensitivity improves with increasing filter group delay and can be increased within constant linear bandwidth by use of higher-order filters.

Journal Article↗

PubMed2003

Fluorescence enhancement from an array of subwavelength metal apertures.

We report the resonant excitation of a fluorescing molecular monolayer applied to a periodic array of subwavelength apertures in a metal film. The peak fluorescence occurs under conditions of maximum transmission of the excitation light, which indicates strong enhancement of the incident light within the apertures under resonant conditions. Fluorescence output normalized to the aperture fill fraction is enhanced by nearly 40 times, and the rate of photobleaching is increased by approximately a factor of 2, suggesting an increase in the fluorescence yield.

Fluorescence↗

PubMed2000

Nonparaxial one-dimensional spatial solitons.

Scalar and vector nonlinear nonparaxial evolution equations are developed for propagation in two-dimensions. Using standard soliton scalings, it is found that nonparaxial propagation is accompanied by higher-order linear and nonlinear terms and an effective quintic nonlinear index. The presence of an intrinsic quintic nonlinearity arising from chi((5)) must also be considered at the order of the analysis. These terms represent corrections to the well-known nonlinear Schrodinger equation. Exact and approximate solutions to these higher-order evolution equations are obtained and are shown to exhibit quasi-soliton behavior based on propagation and collision studies. (c) 2000 American Institute of Physics.

Journal Article↗