Learning Forum

[Joe Francis]

I am trying to simulate the change in refractive index in a substrate when illuminated by a narrowband pulse. I have simulated this pulse being absorbed with FDTD and have exported this data into the CHARGE solver. However the "import optical generation" has a scale factor on the imported data, I found information on one of the examples that claimed that by default the output was scaled to 1w but is this 1w averaged over the whole FDTD simulation, a pulse of 1w for the length of the pulse? any help in understanding this would be appriciated.

[Guilin Sun]

 

Hi Joe, the scale factor is used to multiply the imported optical generation of 1W into actual power, which is usually smaller due to small device. Power usually quantifies the enegy flow per second crossing a surface. Pulse, on the other hand, will depend on the time, which is energy concept. Usually the refractive index changes due to e-h carriers from optical absorption. Thus it might not be the energy quantity that matters. Please think over the physics and mechanism of such change. This link might be helpful : https://optics.ansys.com/hc/en-us/articles/360034382494-Charge-distribution-to-change-in-refractive-index-theory