Comment on "The Quantum State of a Propagating Laser Field"

TL;DR

This paper critiques van Enk and Fuchs's quantum state description of a propagating laser field, clarifies its implications for quantum teleportation, and discusses the feasibility of their proposed measurements.

Contribution

It clarifies that the multimode description does not alter previous teleportation analysis and questions the practicality of the complete measurements proposed.

Findings

Multimode description does not change teleportation analysis

Complete measurements are technologically unfeasible

Proposed measurements may be impossible in principle

Abstract

We comment on the theoretical quantum state of a propagating laser field proposed by van Enk and Fuchs [quant-ph/0104036, quant-ph/0111157] and clarify that the multimode description of the propagating laser field does not modify our analysis of continuous variable quantum teleportation [quant-ph/0103147]. Furthermore we point out that the ``complete measurements'' discussed by van Enk and Fuchs have not been achieved by existing technology and may not be possible even in principle.