Apply minimum linewidth constraint only to a binary design of the waveguide mode converter

waveguide_mode_converter/README.md

@@ -48,3 +48,145 @@ The script will print out CSV-formatted performance metrics. For example,
 -34.11, -0.19
 -30.67, -0.26
 ```
+
+For comparison, the following are the reflectance and transmittance spectra for the topology-optimized designs using Meep with various minimum lengthscales.
+
+1. Minimum lengthscale constraint: 50 nm.
+
+measured lengthscale: 63 nm.
+
+file: converter_meep_min_linewidth_50nm.csv
+
+**reflectance into mode 1: wavelength (μm), reflectance, reflectance (dB)**
+```
+refl:, 1.265, 0.009628, -20.164705
+refl:, 1.270, 0.009643, -20.158021
+refl:, 1.275, 0.009707, -20.128966
+refl:, 1.285, 0.009950, -20.021659
+refl:, 1.290, 0.010118, -19.949185
+refl:, 1.295, 0.010312, -19.866366
+worst-case reflectance (dB):, -19.866366
+```
+
+**transmittance into mode 2: wavelength (μm), transmittance, transmittance (dB)**
+```
+tran:, 1.265, 0.920025, -0.362003
+tran:, 1.270, 0.922174, -0.351873
+tran:, 1.275, 0.924045, -0.343067
+tran:, 1.285, 0.927015, -0.329132
+tran:, 1.290, 0.928125, -0.323937
+tran:, 1.295, 0.928992, -0.319879
+worst-case transmittance (dB):, -0.362003
+```
+
+2. Minimum lengthscale constraint: 60 nm.
+
+measured lengthscale: 81 nm.
+
+file: converter_meep_min_linewidth_60nm.csv
+
+**reflectance into mode 1: wavelength (μm), reflectance, reflectance (dB)**
+```
+refl:, 1.265, 0.000374, -34.275727
+refl:, 1.270, 0.000286, -35.443571
+refl:, 1.275, 0.000265, -35.774808
+refl:, 1.285, 0.000372, -34.299325
+refl:, 1.290, 0.000473, -33.255701
+refl:, 1.295, 0.000588, -32.305168
+worst-case reflectance (dB):, -32.305168
+```
+
+**transmittance into mode 2: wavelength (μm), transmittance, transmittance (dB)**
+```
+tran:, 1.265, 0.963868, -0.159824
+tran:, 1.270, 0.963965, -0.159388
+tran:, 1.275, 0.963685, -0.160648
+tran:, 1.285, 0.962119, -0.167712
+tran:, 1.290, 0.960892, -0.173256
+tran:, 1.295, 0.959421, -0.179906
+worst-case transmittance (dB):, -0.179906
+```
+
+3. Minimum lengthscale constraint: 70 nm.
+
+measured lengthscale: 100 nm.
+
+file: converter_meep_min_linewidth_70nm.csv
+
+**reflectance into mode 1: wavelength (μm), reflectance, reflectance (dB)**
+```
+refl:, 1.265, 0.019693, -17.056968
+refl:, 1.270, 0.017361, -17.604295
+refl:, 1.275, 0.015615, -18.064702
+refl:, 1.285, 0.013498, -18.697453
+refl:, 1.290, 0.012916, -18.888789
+refl:, 1.295, 0.012493, -19.033184
+worst-case reflectance (dB):, -17.056968
+```
+
+**transmittance into mode 2: wavelength (μm), transmittance, transmittance (dB)**
+```
+tran:, 1.265, 0.667054, -1.758389
+tran:, 1.270, 0.675296, -1.705058
+tran:, 1.275, 0.683075, -1.655316
+tran:, 1.285, 0.696382, -1.571525
+tran:, 1.290, 0.700852, -1.543736
+tran:, 1.295, 0.702586, -1.533007
+worst-case transmittance (dB):, -1.758389
+```
+
+4. Minimum lengthscale constraint: 80 nm.
+
+measured lengthscale: 75 nm.
+
+file: converter_meep_min_linewidth_80nm.csv
+
+**reflectance into mode 1: wavelength (μm), reflectance, reflectance (dB)**
+```
+refl:, 1.265, 0.061416, -12.117155
+refl:, 1.270, 0.062535, -12.038793
+refl:, 1.275, 0.063447, -11.975903
+refl:, 1.285, 0.064677, -11.892475
+refl:, 1.290, 0.065058, -11.866985
+refl:, 1.295, 0.065391, -11.844820
+worst-case reflectance (dB):, -11.844820
+```
+
+**transmittance into mode 2: wavelength (μm), transmittance, transmittance (dB)**
+```
+tran:, 1.265, 0.679133, -1.680453
+tran:, 1.270, 0.677549, -1.690590
+tran:, 1.275, 0.674796, -1.708273
+tran:, 1.285, 0.665450, -1.768848
+tran:, 1.290, 0.658723, -1.812969
+tran:, 1.295, 0.650600, -1.866862
+worst-case transmittance (dB):, -1.866862
+```
+
+5. Minimum lengthscale constraint: 90 nm.
+
+measured lengthscale: 113 nm
+
+converter_meep_min_linewidth_90nm.csv
+
+**reflectance into mode 1: wavelength (μm), reflectance, reflectance (dB)**
+```
+refl:, 1.265, 0.007773, -21.094135
+refl:, 1.270, 0.007432, -21.288749
+refl:, 1.275, 0.007204, -21.424158
+refl:, 1.285, 0.007083, -21.497768
+refl:, 1.290, 0.007142, -21.461586
+refl:, 1.295, 0.007244, -21.400120
+worst-case reflectance (dB):, -21.094135
+```
+
+**transmittance into mode 2: wavelength (μm), transmittance, transmittance (dB)**
+```
+tran:, 1.265, 0.619815, -2.077378
+tran:, 1.270, 0.631644, -1.995273
+tran:, 1.275, 0.643311, -1.915788
+tran:, 1.285, 0.666046, -1.764957
+tran:, 1.290, 0.676643, -1.696403
+tran:, 1.295, 0.686333, -1.634649
+worst-case transmittance (dB):, -2.077378
+```