Laser profiles
Warning
This section is currently in development.
- pydantic model picmistandard.PICMI_GaussianLaser[source]
Specifies a Gaussian laser distribution.
More precisely, the electric field near the focal plane is given by:
\[E(\boldsymbol{x},t) = a_0\times E_0\, \exp\left( -\frac{r^2}{w_0^2} - \frac{(z-z_0-ct)^2}{c^2\tau^2} \right) \cos[ k_0( z - z_0 - ct ) - \phi_{cep} ]\]where \(k_0 = 2\pi/\lambda_0\) is the wavevector and where \(E_0 = m_e c^2 k_0 / q_e\) is the field amplitude for \(a_0=1\).
Note
The additional terms that arise far from the focal plane (Gouy phase, wavefront curvature, …) are not included in the above formula for simplicity, but are of course taken into account by the code, when initializing the laser pulse away from the focal plane.
Parameters
- parameter E0: float | None = None
Maximum amplitude of the laser field [V/m]. Specify either a0 or E0 (if both are given, they must be consistent).
- parameter a0: float | None = None
Normalized vector potential at focus. Specify either a0 or E0 (if both are given, they must be consistent).
- parameter centroid_position: list[float] [Required]
Vector of length 3 of floats. Position of the laser centroid at time 0 [m]
- parameter duration: float [Required]
Duration of the Gaussian pulse [s], defined as \(\tau\) in the above formula
- parameter fill_in: bool = True
Flags whether to fill in the empty spaced opened up when the grid moves
- parameter focal_position: list[float] [Required]
Vector of length 3 of floats. Position of the laser focus [m]
- parameter polarization_direction: list[float] [Required]
Unit vector of length 3. Direction of polarization [1]
- parameter propagation_direction: list[float] [Required]
Unit vector of length 3. Direction of propagation [1]
- parameter waist: float [Required]
Waist of the Gaussian pulse at focus [m], defined as \(w_0\) in the above formula
- parameter wavelength: float [Required]
Laser wavelength [m], defined as \(\lambda_0\) in the above formula
Properties
- pydantic model picmistandard.PICMI_AnalyticLaser[source]
Specifies a laser with an analytically described distribution
Parameters can be used in the field expression, with their values given as keyword arguments.
Parameters
- parameter Emax: float | None = None
Maximum amplitude of the laser field [V/m]. Specify either amax or Emax (if both are given, they must be consistent). This should be built into the expression, but some codes require a specified value for numerical purposes.
- parameter amax: float | None = None
Maximum normalized vector potential. Specify either amax or Emax (if both are given, they must be consistent). This should be built into the expression, but some codes require a specified value for numerical purposes.
- parameter field_expression: Expression [Required]
Analytic expression describing the electric field of the laser [V/m]. Expression should be in terms of the position, ‘X’, ‘Y’, in the plane orthogonal to the propagation direction, and ‘t’ the time. The expression should describe the full field, including the oscillitory component. Parameters can be used in the expression with the values given as keyword arguments.
- parameter fill_in: bool = True
Flags whether to fill in the empty spaced opened up when the grid moves
- parameter polarization_direction: list[float] [Required]
Unit vector of length 3. Direction of polarization [1]
- parameter propagation_direction: list[float] [Required]
Unit vector of length 3. Direction of propagation [1]
- parameter user_defined_kw: dict [Optional]
Constants referenced in the field expression, collected from otherwise-unrecognized keyword arguments.
- parameter wavelength: float [Required]
Laser wavelength. This should be built into the expression, but some codes require a specified value for numerical purposes.
Properties