Laser: user optical properties in readme

## Description

This deposition generator is intended for simulations of laser-TCT experiments.

It generates charge, deposited by absorption of a laser pulse in silicon bulk.

This module is not dependent on Geant4. Instead, it implements tracking algorithms and simulations of corresponding physical

phenomena by its own, using internal Allpix geometry.

This deposition generator is mostly intended for simulations of laser-TCT experiments.

It generates charge, deposited by absorption of a laser pulse in detector bulk.

This module is not dependent on Geant4. Instead, it implements tracking algorithms and simulations of corresponding physical phenomena by its own, using internal Allpix geometry.

Current implementation assumes that the laser pulse is a bunch of point-like photons, each traveling in a straight line. A

lookup table \[[@optical_properties]\] is used to determine absorption and refraction coefficients for a given wavelength.

Current implementation assumes that the laser pulse is a bunch of point-like photons, each traveling in a straight line. A lookup table \[[@optical_properties]\] is used to determine absorption and refraction coefficients in silicon for a given wavelength.

The only supported sensor material is silicon, unless optical properties are explicitly set (see *Parameters*).

Multiple photons are produced in *one* event, thus a *single* event models a *single* laser pulse.

  shape will effectively stretch along its direction due to refraction and the actual focus will be further away from the

  source.

* `beam_convergence_angle`: max angle between tracks and `beam_direction`. Needs to be specified for a `converging` beam.

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* `output_plots`: if set `true`, this module will produce histograms to monitor beam shape and also 3D distributions of

  charges, deposited in each detector. Histograms would look sensible even for one-event runs. Defaults to `false`.

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* `output_plots`: if set `true`, this module will produce histograms to monitor beam shape and also 3D distributions of charges, deposited in each detector. Histograms would look sensible even for one-event runs. Defaults to `false`.

* `absorption_length` and `refractive_index`: if both are specified, they override corresponding values from the lookup table. This also allows use of sensor materials other than silicon.

>>>>>>> Laser: user optical properties in readme

## Usage

A simulation pipeline to build an analog detector response would include `DepositionLaser`, `TransientPropagation` and