PR Description

This code enhances laser generation by supporting multiple methods of laser initialization, including gaussian, parser, and from_file. Lasers are instantiated via the Laser class and sequentially added to the Multilaser instancem_multilaser.

However, previously, the methods for reading lasers from an openPMD file—specifically, void GetEnvelopeFromFileHelper() and void GetEnvelopeFromFile()—were directly defined in the Multilaser class. As a result, when these methods were activated, no additional Laser instances could be added to m_multilaser, leading to an incompatibility between from_file and the other methods (gaussian and parser).

Issue addressed

This pull request resolves the conflict by refactoring the code. It moves the member variables and functions related to reading laser data from a file, including:

void GetEnvelopeFromFileHelper ()
void GetEnvelopeFromFile ()
bool m_laser_from_file = false;
/** full 3D laser data stored on the host */
amrex::FArrayBox m_F_input_file;
/** path to input openPMD file */
std::string m_input_file_path;
/** name of the openPMD species in the file */
std::string m_file_envelope_name = "laserEnvelope";
/** index of the iteration in the openPMD file */
int m_file_num_iteration = 0;
/** Geometry of the laser file, 'rt' or 'xyt' */
std::string m_file_geometry = "";
/** Wavelength from file */
amrex::Real m_lambda0_from_file {0.};

from Multilaser class to Laser class. With this change, the laser data can be loaded via the Laser class and then added to m_multilaser, just like with the other initialization methods.

Benefits

Together with PR #1122 and PR #866, this update allows the code to initialize multiple lasers using any combination of parser, gaussian, and from_file methods.The default initialization option for <laser_name>.init_type is now gaussian, with additional options being parser and from_file.

Important Note

Currently, all lasers must share the same central wavelength. If the lasers.lambda0 of a laser does not match the wavelength loaded from the file, the code will raise an error.

Test

This PR is tested through the input script:
From_file_input.txt

And three lasers respectively from different methods are generated.