lsurf.materials.HomogeneousMaterial

class lsurf.materials.HomogeneousMaterial(name, refractive_index, absorption_coef=0.0, scattering_coef=0.0, anisotropy=0.0, propagator=None)[source]

Homogeneous material with constant optical properties.

Properties are uniform throughout space but can depend on wavelength. Supports analytic dispersion models (Sellmeier, Cauchy) or custom functions.

Parameters:

name (str) – Descriptive name for this material.
refractive_index (float or callable) – Refractive index value or function f(wavelength) -> n. If float, uses constant n for all wavelengths. If callable, wavelength is in meters.
absorption_coef (float, optional) – Absorption coefficient α in m⁻¹. Default is 0.
scattering_coef (float, optional) – Scattering coefficient μ_s in m⁻¹. Default is 0.
anisotropy (float, optional) – Henyey-Greenstein anisotropy factor g ∈ [-1, 1]. Default is 0.

refractive_index

Refractive index specification.

Type:: float or callable

absorption_coef

Absorption coefficient in m⁻¹.

Type:: float

scattering_coef

Scattering coefficient in m⁻¹.

Type:: float

anisotropy

Scattering anisotropy factor.

Type:: float

Examples

>>> # Constant refractive index
>>> glass = HomogeneousMaterial("Glass", 1.5)

>>> # Wavelength-dependent (Cauchy dispersion)
>>> def cauchy_n(wavelength):
...     wl_um = wavelength * 1e6
...     return 1.5 + 0.01 / wl_um**2
>>> glass = HomogeneousMaterial("Glass", cauchy_n)

>>> # With absorption (colored glass)
>>> colored_glass = HomogeneousMaterial(
...     "Red Glass", 1.52, absorption_coef=0.1
... )

Notes

For homogeneous materials: - Rays propagate in straight lines (no gradient-driven bending) - Reflection/refraction occurs only at interfaces - Beer-Lambert absorption: I(d) = I₀ exp(-αd) - No GPU kernels are needed (straight-line propagation)

__init__(name, refractive_index, absorption_coef=0.0, scattering_coef=0.0, anisotropy=0.0, propagator=None)[source]

Initialize homogeneous material.

Parameters:

name (str) – Descriptive name for this material.
refractive_index (float or callable) – Refractive index value or function f(wavelength) -> n.
absorption_coef (float, optional) – Absorption coefficient α in m⁻¹. Default is 0.
scattering_coef (float, optional) – Scattering coefficient μ_s in m⁻¹. Default is 0.
anisotropy (float, optional) – Henyey-Greenstein anisotropy factor g ∈ [-1, 1]. Default is 0.
propagator (PropagatorID, optional) – Override the default propagator. Only CPU_GRADIENT is supported.

Raises:

ValueError – If anisotropy is outside [-1, 1].

Methods

`__init__`(name, refractive_index[, ...])	Initialize homogeneous material.
`compute_phase_velocity`(x, y, z, wavelength)	Compute phase velocity v_p = c/n at position.
`default_kernel`()	Return the default propagation kernel for this material type.
`default_propagator`()	Return the default propagator for this material type.
`get_absorption_coefficient`(x, y, z, wavelength)	Get absorption coefficient (constant for homogeneous).
`get_anisotropy_factor`(x, y, z, wavelength)	Get scattering anisotropy factor (constant for homogeneous).
`get_extinction_coefficient`(x, y, z, wavelength)	Get total extinction coefficient (absorption + scattering).
`get_refractive_index`(x, y, z, wavelength)	Get refractive index (position-independent, wavelength-dependent).
`get_refractive_index_gradient`(x, y, z, ...)	Get refractive index gradient (always zero for homogeneous).
`get_refractive_index_gradient_magnitude`(x, ...)	Get magnitude of refractive index gradient \|∇n\|.
`get_scattering_coefficient`(x, y, z, wavelength)	Get scattering coefficient (constant for homogeneous).
`is_homogeneous`()	Check if material has uniform properties (no spatial variation).
`supported_kernels`()	Return list of propagation kernels supported by this material type.
`supported_propagators`()	Return list of propagators supported by this material type.

Attributes

`kernel_id`	Return the kernel ID configured for this material instance.
`propagator_id`	Return the propagator ID configured for this material instance.

__init__(name, refractive_index, absorption_coef=0.0, scattering_coef=0.0, anisotropy=0.0, propagator=None)[source]

Initialize homogeneous material.

Parameters:

name (str) – Descriptive name for this material.
refractive_index (float or callable) – Refractive index value or function f(wavelength) -> n.
absorption_coef (float, optional) – Absorption coefficient α in m⁻¹. Default is 0.
scattering_coef (float, optional) – Scattering coefficient μ_s in m⁻¹. Default is 0.
anisotropy (float, optional) – Henyey-Greenstein anisotropy factor g ∈ [-1, 1]. Default is 0.
propagator (PropagatorID, optional) – Override the default propagator. Only CPU_GRADIENT is supported.

Raises:

ValueError – If anisotropy is outside [-1, 1].

get_refractive_index(x, y, z, wavelength)[source]

Get refractive index (position-independent, wavelength-dependent).

Parameters:

x (float or ndarray) – Position coordinates in meters (ignored for homogeneous).
y (float or ndarray) – Position coordinates in meters (ignored for homogeneous).
z (float or ndarray) – Position coordinates in meters (ignored for homogeneous).
wavelength (float or ndarray) – Wavelength in meters.

Returns:

n – Refractive index.

Return type:

float or ndarray

get_refractive_index_gradient(x, y, z, wavelength)[source]

Get refractive index gradient (always zero for homogeneous).

Parameters:

x (float or ndarray) – Position coordinates in meters.
y (float or ndarray) – Position coordinates in meters.
z (float or ndarray) – Position coordinates in meters.
wavelength (float or ndarray) – Wavelength in meters (unused).

Returns:

grad_n – (0, 0, 0) since ∇n = 0 for homogeneous materials.

Return type:

tuple of (float or ndarray)

get_absorption_coefficient(x, y, z, wavelength)[source]

Get absorption coefficient (constant for homogeneous).

Parameters:

x (float or ndarray) – Position coordinates in meters (ignored).
y (float or ndarray) – Position coordinates in meters (ignored).
z (float or ndarray) – Position coordinates in meters (ignored).
wavelength (float or ndarray) – Wavelength in meters (currently ignored, could extend).

Returns:

alpha – Absorption coefficient in m⁻¹.

Return type:

float or ndarray

get_scattering_coefficient(x, y, z, wavelength)[source]

Get scattering coefficient (constant for homogeneous).

Parameters:

x (float or ndarray) – Position coordinates in meters (ignored).
y (float or ndarray) – Position coordinates in meters (ignored).
z (float or ndarray) – Position coordinates in meters (ignored).
wavelength (float or ndarray) – Wavelength in meters (currently ignored, could extend).

Returns:

mu_s – Scattering coefficient in m⁻¹.

Return type:

float or ndarray

get_anisotropy_factor(x, y, z, wavelength)[source]

Get scattering anisotropy factor (constant for homogeneous).

Parameters:

x (float or ndarray) – Position coordinates in meters (ignored).
y (float or ndarray) – Position coordinates in meters (ignored).
z (float or ndarray) – Position coordinates in meters (ignored).
wavelength (float or ndarray) – Wavelength in meters (ignored).

Returns:

g – Anisotropy factor.

Return type:

float or ndarray

__repr__()[source]

Return string representation with key properties.