Biconvex Parabolic Lens (no lens class)

python

import torch
import torch.nn as nn
import torchlensmaker as tlm
import torch.optim as optim

surface = tlm.Parabola(diameter=15, A=tlm.parameter(0.02)) # y = a*x^2

optics = nn.Sequential(
    tlm.PointSourceAtInfinity(beam_diameter=18.5),
    tlm.Gap(10),
    tlm.RefractiveSurface(surface, material="water-nd", anchors=("origin", "extent")),
    tlm.Gap(2),
    tlm.RefractiveSurface(
        surface, material="water-nd", scale=-1, anchors=("extent", "origin")
    ),
    tlm.Gap(50),
    tlm.FocalPoint(),
)

tlm.show(optics, dim=2)
tlm.show(optics, dim=3)

python

tlm.optimize(
    optics,
    optimizer = optim.Adam(optics.parameters(), lr=3e-4),
    sampling = {"base": 10},
    dim = 2,
    num_iter = 100
).plot()

[  1/100] L=  1.881 | grad norm= 113.95974298312814
[  6/100] L=  1.711 | grad norm= 114.18985216269625
[ 11/100] L=  1.540 | grad norm= 114.39647905454844
[ 16/100] L=  1.368 | grad norm= 114.57999629692958
[ 21/100] L=  1.197 | grad norm= 114.74078984567689
[ 26/100] L=  1.025 | grad norm= 114.879262137514
[ 31/100] L=  0.853 | grad norm= 114.99583542094311
[ 36/100] L=  0.680 | grad norm= 115.090954513795
[ 41/100] L=  0.508 | grad norm= 115.16508853803323
[ 46/100] L=  0.335 | grad norm= 115.21873148931898
[ 51/100] L=  0.162 | grad norm= 115.252401725918
[ 56/100] L=  0.077 | grad norm= 19.478242249783197
[ 61/100] L=  0.105 | grad norm= 115.26640790271479
[ 66/100] L=  0.114 | grad norm= 115.2660678922228
[ 71/100] L=  0.087 | grad norm= 19.579362001128906
[ 76/100] L=  0.077 | grad norm= 19.47226253419699
[ 81/100] L=  0.080 | grad norm= 53.74440553776681
[ 86/100] L=  0.076 | grad norm= 53.731913243376944
[ 91/100] L=  0.076 | grad norm= 19.46708705065629
[ 96/100] L=  0.077 | grad norm= 19.476725869189885
[100/100] L=  0.076 | grad norm= 19.460679330070136

png

python

tlm.show(optics, dim=2, end=60)
tlm.show(optics, dim=3, end=60)

Biconvex Parabolic Lens (no lens class) ​

Biconvex Parabolic Lens (no lens class)