Material¶

Main class¶

class NonlinearTMM.Material(wls, ns)[source]¶

Bases: Material

This class describes the optical parameters of a nonlinear medium. The default constructor takes arrays of wavelengths and complex refractive indices and performs linear interpolation. As a shortcut, __call__ is defined as an alias for GetN.

Parameters:

wlsndarray of floats: Array of wavelengths (m)
nsndarray of complex floats: Corresponding complex refractive indices to the wls array.

Attributes:

chi2_Chi2Tensor: Instance of the _Chi2Tensor helper class to store second-order nonlinearity tensor.

static FromLabPy(materialLabPy: Any) → Material[source]¶

Create a Material from a LabPy Material instance.

Parameters:

materialLabPyLabPy.Material: Source material object from the LabPy test helpers.

Returns:

Material

GetN(wl)¶

Returns refractive index of material at specified wavelength.

Parameters:

wlfloat: Wavelength in meters.

Returns:

complex: Complex refractive index at wavelength wl.

Examples

>>> wls = np.array([400e-9, 600e-9, 800e-9], dtype = float)
>>> ns = np.array([1.5 + 0.3j, 1.7 + 0.2j, 1.8 + 0.1j], dtype = complex)
>>> mat = Material(wls, ns)
>>> mat(600e-9)
1.7 + 0.2j

IsNonlinear()¶

Returns True if the material nonlinearity tensor chi2 is nonzero, False otherwise.

Returns:

bool: True if chi2 tensor is nonzero, False otherwise.

static Static(n: complex | float) → Material[source]¶

Helper method to make material with constant refractive index.

Parameters:

nfloat or complex: Constant value for refractive index

Returns:

Material

Examples

>>> mat = Material.Static(1.5)
>>> mat.GetN(532e-9)
1.5

Helper classes¶

class NonlinearTMM._Chi2Tensor¶

Bases: object

This is a helper class for Material to accommodate the second-order susceptibility tensor. Allows setting nonlinearities by chi2- and by d-values. The initial tensor can be rotated around all three axes.

GetChi2Tensor()¶

Returns rotated 3x3x3 second-order nonlinearity tensor.

Returns:

ndarray(3, 3, 3) of floats

Update(**kwargs)¶

This method changes the values of second-order nonlinearity tensor. By default the tensor is zero, not rotated and distinctFields set to True.

Parameters:

chiXYZfloat, optional: Updates tensor value of second-order nonlinearity, where X, Y, Z denote numbers from 1..3 corresponding to x-, y-, z-axis.
dXKfloat, optional: Updates tensor values by contracted notation, where dXK = 0.5 * chiXYZ and K is defined as: 1 = 11; 2 = 22; 3 = 33; 4 = 23, 32; 5 = 31, 13; 6 = 12, 21.
distinctFieldsbool, optional: If set to True, then assumes that two input waves in nonlinear process are the same (e.g second harmonic generation). If False, then the input fields are not equal (as a result the result will be multiplied by 2). Default is true.
phiXfloat, optional: The rotation angle (radians) around x-axis of the second order nonlinear tensor.
phiYfloat, optional: The rotation angle (radians) around y-axis of the second order nonlinear tensor.
phiZfloat, optional: The rotation angle (radians) around z-axis of the second order nonlinear tensor.

Examples

Updates nonlinear tensor of material and then rotates it.

>>> mat = Material.Static(1.5)
>>> mat.chi2.Update(d11 = 1e-12, d22 = 2e-12, chi23 = 3e-12)
>>> mat.chi2.Update(phiX = 0.2, phiY = 0.5, phiZ = -0.1)