$element total/$photon element pass

$element_total or $photon_element pass are the same commands. It defines the maximum number of elements that photon will go through.
Because the 2D ray tracing program is based on FET mesh element. So the photon will propagate through each elements. Sometimes it will goes into infinity loop if the total reflection condition is occurred. $element_total defines when the simulation program stops.

Example:

  $element_total
  total_photon_number

Example:

  $element_total
  10000000

 Total simulated element number photon past through is 10000000

The $element total/$photon element pass setting in GUI interface is here
Press Ray Tracing and fill in the field for the Stop element step as needed!