Laser Sources#

Classes representing laser beam sources.

class GaussianBeam(optical_power, wavelength, numerical_aperture=None, waist=None, polarization=<Quantity(0, 'degree')>, RIN=-120.0)[source]#

Bases: BaseBeam

Represents a monochromatic Gaussian laser beam focused by a standard lens.

Parameters:

optical_power (Quantity) – The optical power of the laser (in watts).
wavelength (Quantity) – The wavelength of the laser (in meters).
numerical_aperture (Optional[Quantity]) – The numerical aperture (NA) of the lens focusing the Gaussian beam (unitless).
waist (Optional[Quantity]) – The beam waist at the focus, calculated as waist = wavelength / (pi * numerical_aperture) if not provided. Alternatively, if this is provided, the numerical aperture will be computed as numerical_aperture = wavelength / (pi * waist).
polarization (Optional[Quantity]) – The polarization of the laser source in degrees (default is 0 degrees).
RIN (Optional[float]) – The Relative Intensity Noise (RIN) of the laser, specified as dB/Hz. Default is -120.0 dB/Hz, representing a stable laser.

RIN: float | None = -120.0#

amplitude_at(x, y, z=<Quantity(0, 'meter')>)[source]#

Returns the electric field amplitude at a position (x,y) in the focal plane.

For a Gaussian beam, the spatial distribution is:: E(x,y) = E(0) * exp[-(x^2+y^2)/w_0^2]

Returns:

The electric field amplitude at the focus in volts per meter.

Return type:

Quantity

Parameters:

x (Quantity)
y (Quantity)
z (Quantity)

calculate_field_amplitude_at_focus()[source]#

Calculate the electric field amplitude (E0) at the focus for a Gaussian beam.

The electric field amplitude at the focus is given by:

\[E_0 = \sqrt{\frac{4 P}{\pi \epsilon_0 c w_0^2}}\]

where:

P is the optical power of the beam,
epsilon_0 is the permittivity of free space,
c is the speed of light,
w_0 is the beam waist at the focus.

Returns:: The electric field amplitude at the focus in volts per meter.
Return type:: Quantity

get_particle_width(velocity)[source]#

Parameters:: velocity (Quantity)
Return type:: Quantity

waist: Quantity | None = None#

class AstigmaticGaussianBeam(optical_power, wavelength, numerical_aperture_y=None, waist_y=None, numerical_aperture_z=None, waist_z=None, polarization=<Quantity(0, 'degree')>, RIN=0.0)[source]#

Bases: BaseBeam

Represents an astigmatic Gaussian laser beam focused by a cylindrical lens system.

Parameters:

optical_power (Quantity) – The optical power of the laser (in watts).
wavelength (Quantity) – The wavelength of the laser (in meters).
numerical_aperture_y (Optional[Quantity]) – The numerical aperture of the lens along the x-axis (unitless).
waist_y (Optional[Quantity]) – The beam waist along the x-axis. If not provided, it will be computed as: waist_y = wavelength / (pi * numerical_aperture_y).
numerical_aperture_z (Optional[Quantity]) – The numerical aperture of the lens along the y-axis (unitless).
waist_z (Optional[Quantity]) – The beam waist along the y-axis. If not provided, it will be computed as: waist_z = wavelength / (pi * numerical_aperture_z).
polarization (Optional[Quantity]) – The polarization of the laser source in degrees (default is 0 degrees).
RIN (Optional[float]) – The Relative Intensity Noise (RIN) of the laser, specified as a fractional value. Default is 0.0, representing a perfectly stable laser.

RIN: float | None = 0.0#

amplitude_at(x, y, z=<Quantity(0, 'meter')>)[source]#

Returns the electric field amplitude at position (x,y) in the focal plane.

For an astigmatic Gaussian beam, the distribution is:: E(x,y) = E(0,0) * exp[-(x^2/w_{0x}^2) - (y^2/w_{0y}^2)]

Returns:

The electric field amplitude at the focus in volts per meter.

Return type:

Quantity

Parameters:

x (Quantity)
y (Quantity)
z (Quantity)

calculate_field_amplitude_at_focus()[source]#

Calculate the electric field amplitude (E0) at the focus for an astigmatic Gaussian beam.

The electric field amplitude at the focus is given by:

\[E_0 = \sqrt{\frac{2 P}{\pi \epsilon_0 c w_{0x} w_{0y}}}\]

where:

P is the optical power of the beam,
epsilon_0 is the permittivity of free space,
c is the speed of light,
w_{0x} is the beam waist at the focus along the x-axis,
w_{0y} is the beam waist at the focus along the y-axis.

Returns:: The electric field amplitude at the focus in volts per meter.
Return type:: Quantity

get_particle_width(velocity)[source]#

Parameters:: velocity (Quantity)
Return type:: Quantity

numerical_aperture_z: Quantity | None = None#

waist_y: Quantity | None = None#

waist_z: Quantity | None = None#