Coherent and Incoherent Phase Retrieval Using Gaussian Beam Modes

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 dete...

Full description

Saved in:
Bibliographic Details
Main Authors: O'Sullivan, Creidhe, Withington, Stafford, Murphy, J A
Format: Report
Language:English
Subjects:
AQ F02-02-0127
BEAMS(RADIATION)
COHERENT ELECTROMAGNETIC RADIATION
COMPONENT REPORT
DISTRIBUTION
ENTROPY
FAR INFRARED RADIATION
FITTINGS
FOREIGN REPORTS
FREQUENCY BANDS
GAUSSIAN NOISE
INCOHERENCE
INTENSITY
MATHEMATICAL ANALYSIS
MODE COEFFICIENTS
NOISE(ELECTRICAL AND ELECTROMAGNETIC)
OPTICAL PROPERTIES
Optics
PHASE RETRIEVAL TECHNIQUES
PLANAR STRUCTURES
STATISTICAL PROCESSES
SUBMILLIMETER WAVES
SYMPOSIA
TERAHERTZ EMISSION
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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. Prepared in cooperation with GMM, VDE/VDE-Gesellschaft Mikroelektronik, Mikro- und Feinwerktechnik; ITS, Informationstechnische Gesellschaft im VDE; National Univ. of Ireland, Maynooth, Ireland. This article is from the THz Conference 2000 pp153-156. This article is from ADA398789 International Conference on Terahertz Electronics (8th), Held in Darmstadt, Germany on 28-29 September 2000