Transient simulation in Lumerical Device for oscillator


How can I use transient simulation in Lumerical Device? My structure is a Graphene MOS transistor which operates as terahertz oscillator, so I should simulate Drain current of the transistor versus time. Based on the paper (, Drain current must oscillate in time but Drain current don’t oscillate in my following simulation. How can I do this correctly?
1.ldev (6.1 MB)



Dear @majid.aalizadeh,

A transient simulation needs at least one input to be defined as function of time. This input usually is one of the boundary conditions (by setting the “bc mode” to transient as shown below) or by setting one of the sources to turn on or off at specific times from the transient tab of the CHARGE solver (as shown below). This of course needs that a source object (usually optical generation) be added to the simulation. Otherwise, there will be no time dependent effect on the simulation. Currently your simulation does not have either of these defined.

I’m not an expert in oscillators but to my knowledge, an oscillator needs some sort of starter or trigger (usually a crystal) to operate and I’m not sure how you can define this in the CHARGE solver especially because the transient simulation does not support a periodic pulse (with specific frequency) and can only take a non-periodic (or one period) pulse.