arXiv subjects

Henry Haig

Publications and source records attributed to Henry Haig.

3 recordsLinked to original sources

arXiv2025

Observation of stability of Gaussian beams and off-axis beam-cleaning in graded-index media

While nonlinear effects in graded-index (GRIN) multimode fibers have been studied extensively, little is known about nonlinear effects in larger GRIN waveguides, where the number of modes approaches infinity and modal dispersion becomes negligible. Here we show that Gaussian beams remain nearly invariant even with large nonlinear phase accumulation and on- or off-axis trajectories in GRIN rods. In addition, spatially-complex beams can undergo self-cleaning to single-lobed profiles for both on- and off-axis trajectories. Numerical simulations exhibit the features observed in experiments, and a general interpretation of these results that makes connection to beam-cleaning phenomena observed in GRIN fibers is proposed.

physics.optics↗

arXiv2023

Spectral Speckle Customization

Speckle patterns are used in a broad range of applications including microscopy, imaging, and light-matter interactions. Tailoring speckles' statistics can dramatically enhance their performance in applications. We present an experimental technique for customizing the spatio-spectral speckled intensity statistics of optical pulses at the output of a complex medium (a disordered multimode fiber) by controlling the spatial profile of the input light. We demonstrate that it is possible to create ensembles of independent speckle patterns with arbitrary statistics at a single wavelength, simultaneously at decorrelated wavelengths, and even tailored statistics across an entire pulse spectrum.

physics.optics↗

arXiv2021

Multimode Mamyshev Oscillator

We present a spatiotemporally mode-locked Mamyshev oscillator. A wide variety of multimode mode-locked states, with varying degrees of spatiotemporal coupling, are observed. We find that some control of the modal content of the output beam is possible through the cavity design. Comparison of simulations to experiments indicates that spatiotemporal mode-locking is enabled by nonlinear intermodal interactions and spatial filtering, along with the Mamyshev mechanism. This work represents a first exploration of spatiotemporal mode-locking in an oscillator with the Mamyshev saturable absorber.

physics.optics↗