maxwelllink.tools.pulses module

Predefined laser electric-field profiles for MaxwellLink simulations.

These helpers return callables f(t_au) that evaluate the electric field in atomic units at time t_au.

maxwelllink.tools.pulses.cosine_drive(amplitude_au=1.0, omega_au=0.1, phase_rad=0.0, t_start_au=0.0, t_end_au=1e10)[source]

Return a continuous cosine drive.

\[E(t) = A \cos(\omega t + \phi)\]
Parameters:

  • amplitude_au (float, default: 1.0) – Oscillation amplitude in atomic units.

  • omega_au (float, default: 0.1) – Angular frequency in atomic units.

  • phase_rad (float, default: 0.0) – Phase offset in radians.

  • t_start_au (float, default: 0.0) – Time before which the drive is zero (atomic units).

  • t_end_au (float, default: 1e10) – Time after which the drive is zero (atomic units).

Returns:

A cosine drive suitable for steady-state excitation.

Return type:

callable

maxwelllink.tools.pulses.gaussian_enveloped_cosine(amplitude_au=1.0, t0_au=0.0, sigma_au=10.0, omega_au=0.1, phase_rad=0.0, t_start_au=0.0, t_end_au=1e10)[source]

Return a Gaussian-enveloped cosine drive.

\[E(t) = A \exp\left(-\frac{(t - t_0)^2}{2 \sigma^2}\right) \cos\bigl(\omega (t - t_0) + \phi\bigr)\]
Parameters:

  • amplitude_au (float, default: 1.0) – Peak field amplitude in atomic units.

  • t0_au (float, default: 0.0) – Temporal center of the pulse in atomic units.

  • sigma_au (float, default: 10.0) – Temporal sigma in atomic units.

  • omega_au (float, default: 0.1) – Angular frequency of the cosine wave in atomic units.

  • phase_rad (float, default: 0.0) – Phase of the cosine wave (radians).

  • t_start_au (float, default: 0.0) – Time before which the pulse is zero (atomic units).

  • t_end_au (float, default: 1e10) – Time after which the pulse is zero (atomic units).

Returns:

A function f(t_au) for use as a time-dependent electric field.

Return type:

callable

maxwelllink.tools.pulses.gaussian_pulse(amplitude_au=1.0, t0_au=0.0, sigma_au=10.0, t_start_au=0.0, t_end_au=1e10)[source]

Return a Gaussian pulse drive.

\[E(t) = A \exp\left(-\frac{(t - t_0)^2}{2 \sigma^2}\right)\]
Parameters:

  • amplitude_au (float, default: 1.0) – Peak field amplitude in atomic units.

  • t0_au (float, default: 0.0) – Temporal center of the pulse in atomic units.

  • sigma_au (float, default: 10.0) – Temporal sigma in atomic units.

  • t_start_au (float, default: 0.0) – Time before which the pulse is zero (atomic units).

  • t_end_au (float, default: 1e10) – Time after which the pulse is zero (atomic units).

Returns:

A function f(t_au) that evaluates the Gaussian pulse at t_au.

Return type:

callable

maxwelllink.tools.pulses.k_parallel_pulse(cavity, envelope, omega_au, k_parallel_au, direction='y', center=(0.5, 0.5), size=(0.1, 0.1), amplitude_au=1.0, phase_rad=0.0, target='molecule', projection_axis=None)[source]

Build a multimode pulse with a selected in-plane wave vector.

The returned object is a callable source(t_au) with shape (len(source.excited_grid_list),) for target="molecule" or (len(source.excited_mode_list),) for target="photon". It can be passed directly to maxwelllink.MultiModeSimulation as either molecule_pulse_drive or photon_pulse_drive.

The physical in-plane wave-vector scale is the one used by maxwelllink.FabryPerotCavity’s planar dispersion:

\[\omega_k = \sqrt{\omega_c^2 + k_{\parallel,x}^2 + k_{\parallel,y}^2}.\]

direction="x" and "y" are shorthands for the in-plane wave vectors [k_parallel_au, 0] and [0, k_parallel_au], while direction="xy" takes a length-2 sequence [kx_au, ky_au]. In all cases the spatial phase over the fractional coordinates is

\[\phi(x, y) = \pi k_{x,\mathrm{au}} (x - x_0) / \Delta\omega_x + \pi k_{y,\mathrm{au}} (y - y_0) / \Delta\omega_y.\]
Parameters:

  • cavity – A FabryPerotCavity instance. It must expose grid_xy and the relevant delta_omega_*_au value.

  • envelope (Callable[[float], float] | float) – Time-domain envelope callable envelope(t_au) or constant scalar multiplier. Use helpers such as gaussian_pulse(); the carrier cos(omega_au * t - k*r) is supplied by this function. Passing 1.0 gives a continuous cosine source with grid-dependent phases.

  • omega_au (float) – Carrier angular frequency in atomic units.

  • k_parallel_au (float | Sequence[float]) – Physical in-plane wave-vector contribution in atomic units, in the same units as delta_omega_x_au / delta_omega_y_au. For direction="x" or "y", this must be a scalar. For direction="xy", this must be a length-2 sequence [kx_au, ky_au].

  • direction (str) – In-plane propagation direction: "x", "y", "xy", "+x", "-x", "+y", "-y", "+xy", or "-xy". For "xy", the optional sign is applied to both sequence components.

  • center (Sequence[float]) – Source center (x, y) in fractional cavity coordinates.

  • size (Sequence[float]) – Full source window size (size_x, size_y) in fractional cavity coordinates. A smooth Hann window is applied inside this rectangle.

  • amplitude_au (float) – Additional peak amplitude multiplier.

  • phase_rad (float) – Global carrier phase in radians.

  • target (str) – Source target, either "molecule" or "photon". Molecule-targeted sources return one value per selected molecular grid point. Photon- targeted sources project the same spatial source onto cavity modes and return one value per selected mode.

  • projection_axis (str | None) – Mode-function component used for photon-target projection. Defaults to "y" for target="photon" and is ignored for target="molecule".

Returns:

Callable source object with attributes target, excited_grid_list, excited_mode_list, grid_xy, spatial_window, spatial_phase, mode_complex_amplitude, and k_order. k_order is always a length-2 array holding the in-plane wave vector in units of the mode spacing along each axis.

Return type:

callable

maxwelllink.tools.pulses.k_parallel_pulse_with_seed(cavity, envelope, omega_au, k_parallel_au, direction='y', center=(0.5, 0.5), size=(0.1, 0.1), amplitude_au=1.0, phase_rad=0.0, target='molecule', projection_axis=None)[source]

Build a k-parallel pulse that accepts additional vortex seeds.

This function takes the same arguments as k_parallel_pulse(). After construction, call add_vortex_seed() one or more times. The returned object can then be passed directly to MultiModeSimulation as its photon or molecule pulse drive.

Parameters:

  • envelope (Callable[[float], float] | float)

  • omega_au (float)

  • k_parallel_au (float | Sequence[float])

  • direction (str)

  • center (Sequence[float])

  • size (Sequence[float])

  • amplitude_au (float)

  • phase_rad (float)

  • target (str)

  • projection_axis (str | None)

Return type:

KParallelPulseWithSeed