Photonics and Nonlinear Optics Simulation

Where the standard reductions lose validity

Standard time-domain tools model nonlinearity as a perturbative polarization expansion on a linear host. That treatment holds at low conversion and slow envelopes.

It stops holding when the drive is strong, the pump depletes, the spectrum is broad, or the pulse is few-cycle. We solve the equations those models reduce from.

What is different here

Nothing is truncated. A χ⁽ⁿ⁾ series is cut off at an order chosen before the run. Ours has no series to cut.
The carrier is resolved. There is no envelope, so carrier-envelope phase and few-cycle shape are physical. Envelope solvers have to assume them.

Where we are aiming

Ultrafast and attosecond photonics. Few-cycle and octave-spanning pulses break the envelope approximation NLSE tools are built on.
Frequency conversion in metasurfaces and thin-film lithium niobate. Undepleted-pump solvers work at low conversion. Under pump depletion, cascaded processes, and pulsed driving, they strain.
Laser-induced damage. The field changes the material and the changed material changes the field, at once. Today that is split across a field solver and a loosely coupled material model.

Nonlinear optics

Where the standard reductions lose validity

What is different here

Where we are aiming

Bring us the problem your tools don't quite cover