Related Experiment Video
Updated: Aug 7, 2026

Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
Published on: August 5, 2013
Stability of periodic paraxial optical systems
1Dipartimento di Fisica, Istituto Nazionale per la Fisica della Materia and CEQSE-CNR, Politecnico di Milano, Piazza L. da Vinci, 32 I-20133 Milano, Italy.
Stable periodic optical systems become unstable with random perturbations, similar to Anderson localization. Finite aperture effects and complex paraxial optics restore stability in these focusing systems.
Area of Science:
- Optics and Photonics
- Wave Propagation
- Disordered Systems
Background:
- Periodic paraxial systems and optical resonators are fundamental in optics.
- Stochastic perturbations can significantly alter system behavior.
- Anderson localization describes wave behavior in disordered media.
Purpose of the Study:
- To investigate the stability of periodic paraxial systems under stochastic perturbations.
- To explore the connection between ray displacement and Anderson localization.
- To identify conditions for restoring stability in focusing systems.
Main Methods:
- Analysis of ray propagation using paraxial geometric optics.
- Mathematical modeling of stochastic perturbations in periodic sequences.
- Incorporation of finite aperture effects and complex paraxial optics.
Main Results:
- Periodic paraxial systems and optical resonators exhibit instability when subjected to stochastic perturbations.
- Ray displacements show exponential divergence, analogous to Anderson localization.
- Stability is re-established by considering finite aperture effects and complex paraxial optics.
Conclusions:
- Stochastic perturbations fundamentally destabilize periodic paraxial optical systems.
- The observed instability is closely related to Anderson localization phenomena.
- Finite aperture and complex paraxial optics are crucial for understanding and restoring stability in optical resonators.
Related Concept Videos
Oscillations about an Equilibrium Position
Stability of Equilibrium Configuration
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
Stability of Equilibrium Configuration: Problem Solving
Problem-solving in the context of the stability of equilibrium configuration...
Stability of structures
Pole and System Stability
Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's response.
Stability
The stability of an LTI system is determined by the roots of its characteristic equation, known as poles. A system is stable if it produces a bounded...

