Multi-order Diffraction

Script: 8_multi_order_diffraction.py

Visualize multi-order diffraction in the PSF of a hybrid refractive–diffractive lens. A ray-tracing model (e.g. Zemax) traces one diffraction order at a time; the ray–wave model carries all orders in the wavefront at once, so a single PSF computation includes every order's contribution.

What it demonstrates

• Computing the PSF of a grating-DOE hybrid lens with the ray–wave model.
• The wavelength dependence of multi-order diffraction (R/G/B).

Run

python 8_multi_order_diffraction.py

Key code

import torch
from deeplens import HybridLens

lens = HybridLens(filename="./datasets/lenses/hybridlens/a489_grating.json",
                  dtype=torch.float64)

for wvln in [0.48, 0.55, 0.65]:
    psf = lens.psf(points=[0.0, 0.0, -10000.0], wvln=wvln, spp=1_000_000)
    analyze_psf(psf, save_name=f"./psf_{wvln}")

Results

PSF at three wavelengths — the diffraction orders shift with wavelength:

λ = 0.48 µm	λ = 0.55 µm	λ = 0.65 µm

Center-line profile (λ = 0.55 µm)

See also

• Hello HybridLens · Diffractive surfaces