$tracephase

$tracephase is an experimental commands for tracing the phase of the photon.

$tracephase
type
wave_length  (initial_phase)  

If type =1, just set the wavelength of the light
If type =2, decide the wave length and the initial phase

For example

$tracephase
1
450.0

or

$tracephase
2
450.0  0.23