Plesty Fine-Structure Analyzer

A PLESTY analyzer for the exciton fine-structure splitting (FSS) of every line in a polarization-resolved PL sweep.

Installation

uv add plesty-fss

or, from source:

git clone https://gitlab.com/plesty/hub/analyzers/plesty-fss.git
cd plesty-fss
uv sync

Running the analyzer

from plesty.lib.data import SpectrumData
from plesty.fss import FineStructure

spectrum = SpectrumData.from_run(run, coordinates=("hwp_deg",))
outputs = FineStructure(
    angle="hwp_deg",
    rotator="hwp",  # "polarizer" for a rotating polarizer, "qwp" for a quarter-wave plate
    fit_options={"peaks": [775.0], "window": 0.3},
)(spectrum=spectrum)

result = outputs["fine_structure"]
result["fss"], result["fss_err"]  # µeV, one per line
result["fss_wavelength"]  # the same splitting in the wavelength unit

fit_options are passed to plesty.lib.analyzer.SpectrumFit. See the documentation for the outputs and the model.

To plot the result — each line's energy shift against the angle with the fit and its residuals — install the plot extra (uv add "plesty-fss[plot]"):

from plesty.fss.plot import plot_fine_structure

plot_fine_structure(outputs["fine_structure"], outputs["fit"]).savefig("fine_structure.png")