Source code for ggf.stress

from . import boyde2009
from .geometry import fiber_distance_capillary  # noqa: F401

VALID_MODELS = ["boyde2009"]

[docs]def get_stress(model, semi_major, semi_minor, object_index, medium_index, effective_fiber_distance=100e-6, mode_field_diameter=3e-6, power_per_fiber=.6, wavelength=1064e-9, n_points=100, verbose=False): """Compute the optical stress profile in the optical stretcher Parameters ---------- model: str Model to use, one of: `boyde2009` semi_major: float Semi-major axis of an ellipse fit to the object perimeter [m] semi_minor: float Semi-minor axis of an ellipse fit to the object perimeter [m] object_index: float Refractive index of the object medium_index: float Refractive index of the surrounding medium effective_fiber_distance: float Effective distance between the two trapping fibers relative to the medium refractive index [m]. For an open setup, this is the physical distance between the fibers. For a closed setup (capillary), this distance takes into account the refractive indices and thicknesses of the glass capillary and index matching gel. For the closed setup, the convenience function :func:`ggf.fiber_distance_capillary` can be used. mode_field_diameter: float The mode field diameter MFD of the fiber used [m]. Note that the MFD is dependent on the wavelength used. If the manufacturer did not provide a value for the MFD, the MFD can be approximated as ``3*wavelenth`` for a single-mode fiber. power_per_fiber: float The laser power coupled into each of the fibers [W] wavelength: float The laser wavelength used for the trap [m] n_points: int Number of points to compute. verbose: int Increases verbosity Returns ------- theta: 1d ndarray of length `n_points` Polar angles [rad] sigma: 1d ndarray of length `n_points` Radial stress profile along `theta` [Pa] """ if model not in VALID_MODELS: msg = "`model` must be one of {}, got '{}'".format(VALID_MODELS, model) raise ValueError(msg) if model == "boyde2009": func = boyde2009.get_stress return func( semi_major=semi_major, semi_minor=semi_minor, object_index=object_index, medium_index=medium_index, effective_fiber_distance=effective_fiber_distance, mode_field_diameter=mode_field_diameter, power_per_fiber=power_per_fiber, wavelength=wavelength, n_points=n_points, verbose=verbose)