Comment on: Reply to comment on `Perfect imaging without negative refraction'

TL;DR

This paper clarifies that perfect imaging in Maxwell's fisheye lens can be achieved without active drains, countering previous claims that suggested their necessity, thus advancing understanding of optical imaging systems.

Contribution

It demonstrates that causal solutions for perfect imaging do not require active localized drains, challenging prior assertions and clarifying the conditions for perfect imaging in Maxwell's fisheye lens.

Findings

Causal solutions can be obtained without active drains.

Challenges the claim that active drains are necessary for perfect imaging.

Provides theoretical clarification on Maxwell's fisheye lens imaging.

Abstract

Whether or not perfect imaging is obtained in the mirrored version of Maxwell's fisheye lens is debated in the comment/reply sequence [Blaikie-2010njp, Leonhardt-2010njp] discussing Leonhardt's original paper [Leonhardt-2009njp]. Here we show that causal solutions can be obtained without the need for an "active localized drain", contrary to the claims in [Leonhardt-2010njp].