Related Experiment Video
Updated: May 23, 2026

Using Informational Connectivity to Measure the Synchronous Emergence of fMRI Multi-voxel Information Across Time
Published on: July 1, 2014
Disorder mapping in VCSELs using frequency-selective feedback
T Ackemann1, N Radwell, Y Noblet
1SUPA and Department of Physics, University of Strathclyde, Glasgow, UK. thorsten.ackemann@strath.ac.uk
Abstract:
We report on a simple method with a high spectral and spatial resolution for mapping variations in the cavity resonance of a plano-planar broad-area laser based on frequency-selective feedback. The demonstration experiment uses a vertical-cavity surface-emitting-laser (VCSEL), in which growth induced inhomogeneities are of particular importance. It relies only on a standalone laser with a narrow-bandwidth passive filter avoiding the need for an expensive tunable laser or high-resolution spectrometer.
Related Concept Videos
Frequency-Domain Interpretation of PD Control
The proportional control gain, combined with the system's...
Frequency-dependent Selection
Root Loci for Positive-Feedback Systems
The construction rules for the root locus in positive feedback systems are similar to those in...
Feedback control systems
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...
State Space to Transfer Function
The transformation process begins with the state-space representation, characterized by the state equation and the output equation. These equations are typically represented as:
