Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1905.05662

Real-time spectral analysis of ultrafast pulses using a free-space angular chirp enhanced delay

Yiqing Xu·Stuart G. Murdoch
View original source ↗Read source document ↗Export metadata ↓

Abstract

Frequency to time mapping is a powerful technique for observing ultrafast phenomena and non-repetitive events in optics. However, many optical sources operate in wavelength regions, or at power levels, that are not compatible with standard frequency to time mapping implementations. The recently developed free-space angular chirp enhanced delay (FACED) removes many of these limitations, and offers a linear frequency to time mapping in any wavelength region where high-reflectivity mirrors and diffractive optics are available. In this work, we present a detailed formulation of the optical transfer function of a FACED device. Experimentally, we verify the properties of this transfer function, and then present simple guidelines to guarantee the correct operation of a FACED frequency to time measurement. We also experimentally demonstrate the real-time spectral analysis of femtosecond and picosecond pulses using this system.

Explore related subjects

physics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yiqing Xu, Stuart G. Murdoch. 2019-05-14. Real-time spectral analysis of ultrafast pulses using a free-space angular chirp enhanced delay. https://doi.org/10.1364/ol.44.003697

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Geometric Phases and Holonomy in Structured Optical Fields

Geometric phases are widely used in modern optics, yet their meaning and underlying geometry depend on the actual physical settings, which can substantially differ from one another. This tutorial article introduces geometric phases in nanophotonic systems, focusing on the interaction of structured light with nanostructures or metaatoms. We compare the present setting with conventional geometric phases of structured-light optics and show that similar phase laws may correspond to genuinely different underlying geometries. Our aim is to provide a pedagogical bridge between the mathematical language of geometric phases and experimentally relevant examples from nanophotonics.

physics.optics↗
arXiv2026

Induced Directional Switching of Platicon Microcombs in Photonic Crystal Ring Resonators

Microcombs in normal-dispersion photonic crystal ring resonators (PhCRs) are versatile building blocks for next-generation integrated photonic circuits, but their inherent backward-propagation bias necessitates optical circulators or complex filtering for comb extraction, creating a significant bottleneck for full on-chip integration and precluding self-injection locking schemes. In this work, we introduce Side-mode Induced Forward Forcing (SIFF), a robust method to control and reverse this directionality. By engineering auxiliary mode splittings on resonances adjacent to the pump, we steer the nonlinear dynamics to favor stable, forward-propagating platicon states. We identify an optimal coupling condition that ensures forward-comb dominance across a wide parameter range. Our findings, validated numerically and experimentally, enable circulator-free, integrated normal-dispersion microcombs compatible with self-injection locking, offering a scalable architecture for compact telecommunications and sensing systems.

physics.optics↗
arXiv2026

Programmable Intrinsic Circularly Polarized Emission

Circularly polarized luminescence (CPL) is central to chiral photonics, yet programming circularly polarized emission at the nanoscale remains challenging. Here, we program intrinsic CPL at its microscopic origin in laser-written all-inorganic perovskite nanocrystals embedded in glass. High-resolution transmission electron microscopy reveals a core-shell-like variation in interplanar spacing associated with intrinsic CPL, consistent with torsional lattice distortion. The torsional lattice distortion breaks inversion symmetry, while density functional theory calculations show that it lifts the spin degeneracy of the band-edge electronic states. Power-dependent measurements further reveal a transition from birefringence-mediated circular polarization to intrinsic CPL, accompanied by the emergence of a distinct core-shell-like lattice distortion in the nanocrystals. By tuning the incident linear polarization angle and focal depth, we deterministically control both the handedness and magnitude of the intrinsic CPL, with |glum| of approximately 4 ^ 10^-3. These results show that programmable intrinsic CPL originates from the structural and electronic properties of the emitting nanocrystals, enabling circularly polarized emission to be controlled at its microscopic origin and spatially encoded within a monolithic material.

physics.optics↗