Biomedical subjects

G Ronald Hadley

Publications and source records attributed to G Ronald Hadley.

2 recordsLinked to original sources

PubMed2006

Peak-power limits on fiber amplifiers imposed by self-focusing.

We have numerically investigated the behavior of the fundamental mode of a step-index, multimode (MM) fiber as the optical power approaches the self-focusing limit (P(crit)). The analysis includes the effects of gain and bending (applicable to coiled fiber amplifiers). We find power-dependent, stationary solutions that propagate essentially without change at beam powers approaching P(crit) in straight and bent fibers. We show that in a MM fiber amplifier seeded with its fundamental eigenmode at powers <<P(crit), the transverse spatial profile adiabatically evolves through a continuum of stationary solutions as the beam is amplified toward P(crit).

Journal Article↗

PubMed2004

Bragg fiber design for linear polarization.

A new design is presented for Bragg fibers that allows low-loss propagation for linearly polarized light. Predictions based on a simple ray model show that approximately doubling the thickness of the first wall layer results in low losses at TM-like boundaries while keeping TE-like boundary losses manageable. This contrasts sharply with conventional quarter-wave designs that are extremely low loss for TE01 modes but very high loss for linear polarization. We fabricate Bragg fibers based on this design concept in a Si/SiO2 system and verify experimentally that they propagate linearly polarized light with losses less than 6 dB/cm over a 60-nm spectral range.

Journal Article↗