Thank you for the reply.
I am trying to build up the model according to the paper “Directly Reflectivity Modulated Laser” 01.pdf (1.5 MB) with correct representation of both static tunable lasing spectrum, dynamic eye diagram and small signal EO response. So I proceed the simulation in time domain using Transient Sample Mode (TSM) solver since I want to get the dynamic response of the circuit.
I have had the following circuit model (RSOA + phase shifter+Vernier ring filter (self built compact model)+ Michelson Interferometer Mirror (MIM, self built compact model))with reasonable static tunable laser spectrum and dynamic eye diagram.
Static lasing spectrum:
Dynamic eye diagram: (25Gbps OOK)
But I have a problem when trying to use the ENA to get the EO response of the laser modulation (modulation signal is applied to either arm of the MIM) matching the experimental result. My main target is to get the EO response down to KHz ~ MHz range to confirm the ~100KHz laser relaxation frequency :
Another theoretical calculation of the laser relaxation frequency:
Current simulation result:
I think the problem is partially coming from the ENA simulation bandwidth linked to the circuit sampling rate (which is quite high 10s THz for current laser simulation), so that I could not get enough resolution at the small frequency range. And the total simulation time increases dramatically when I increase the “number of points” parameter in the ENA. And it seems to me the minimum resolution of ENA is ~0.1GHz.
I have also thought about sending sinusoidal wave (with different frequency) into the circuit and capture the optical oscillation using OVA/OOSC, but the simulation time for a 100KHz frequency wave will be also long.
Do you have any recommendations for getting the EO response down to KHz frequency resolution while maintaining the limited simulation time/memory?