Coherent and Incoherent Phase Retrieval Using Gaussian Beam Modes
Abstract
Phase retrieval techniques are important at terahertz frequencies where it is often difficult to determine the phase of a field directly. In this paper we present a phase retrieval technique based on a Gaussian-Beam formalism. We show how the complex mode coefficients of a coherent field can be determined by fitting to intensity distributions at any two planes. We extend the analysis to incoherent or partially-coherent fields by working in terms of coherence matrices rather than mode coefficients. Working with the coherence matrix also allows us to vary the entropy of the field as part of the fitting process and to handle the problem of noise in the measurements more correctly. We illustrate our techniques with some simple examples.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 29, 2000
- Accession Number
- ADP011762
Entities
People
- Creidhe O'sullivan
- J. A. Murphy
- Stafford Withington
Organizations
- University of Cambridge