Focus models the optical effect of a focusing element, i.e., it changes the curvature of an incident complex field. More precisely, Focus applies a unit-amplitude quadratic-phase factor to the incident complex field. The sign convention is that positive "focusDistance" makes the wavefront more convergent, while negative "focusDistance" makes the wavefront less convergent, regardless of the direction of propagation. The focus is applied to both incoming and outgoing light that passes through the Focus module.

Parameters
None
Inputs
focusDistance	Recallable<float>	Focus distance (m); must be a "Recallable", which supports looking back in time	recallableFloat(1.00e20)
incomingIncident	WaveTrain	Describes all light incident from the "incoming" direction	WaveTrain()
outgoingIncident	WaveTrain	Describes all light incident from the "outgoing" direction	WaveTrain()
Outputs
incomingTransmitted	WaveTrain	Describes all light transmitted in the "incoming" direction
outgoingTransmitted	WaveTrain	Describes all light transmitted in the "outgoing" direction
Subsystems
Last Saved: Mon Feb 04 13:49:16 MST 2008 by TVE version 2008A