Biomedical subjects

Lifeng Li

Publications and source records attributed to Lifeng Li.

3 recordsLinked to original sources

PubMed2003

Measurement of phase differences between the diffracted orders of deep relief gratings.

Measurement of the phase difference between the 0th and the 1st transmitted diffraction orders of a symmetrical surface-relief grating recorded on a photoresist film is carried out by replacement of the grating in the same setup with which it was recorded. The measurement does not depend on lateral shifts of thereplaced grating relative to the interference pattern, on environmental phase perturbations or on the wave-front quality of the interfering beams. The experimental data agree rather well with theoretical results calculated for sinusoidal profiled gratings.

Journal Article↗

PubMed2003

Note on the S-matrix propagation algorithm.

A set of full-matrix recursion formulas for the W --> S variant of the S-matrix algorithm is derived, which includes the recent results of some other authors as a subset. In addition, a special type of symmetry that is often found in the structure of coefficient matrices (W matrices) that appear in boundary-matching conditions is identified and fully exploited for the purpose of increasing computation efficiency. Two tables of floating-point operation (flop) counts for both the new W --> S variant and the old W --> t --> S variant of the S-matrix algorithm are given. Comparisons of flop counts show that in performing S-matrix recursions in the absence of the symmetry, it is more efficient to go directly from W matrices to S matrices. In the presence of the symmetry, however, using t matrices is equally and sometimes more advantageous, provided that the symmetry is utilized.

Journal Article↗

PubMed2002

Convergence of electromagnetic field components across discontinuous permittivity profiles: comment.

The inverse rule that is described in a recent paper [J. Opt. Soc. Am. A 17, 491 (2000)] is not a multiplication rule for multiplying two infinite series, because it does not address how the terms of two series being multiplied are combined to form the product series. Furthermore, it is not the one that is being used in numerical practice. Therefore the insight that the paper provides into why the inverse rule yields correct results at the points of complementary discontinuities is questionable.

Journal Article↗