Merge pull request #67 from oskooi/metagrating_meep_adjoint_fix

Fix eigenmode coefficient objective function in Meep metagrating optimization
NanoComp · Jun 22, 2024 · a065188 · a065188
2 parents 18d8bc6 + 683c924
commit a065188
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Showing 2 changed files with 33 additions and 11 deletions.
diff --git a/Metagrating3D/metagrating_meep_opt_1d.py b/Metagrating3D/metagrating_meep_opt_1d.py
@@ -1,5 +1,5 @@
 # This python script is for maximizing the diffraction efficiency of the m=+1 order
-# for a 3D metagrating with a 1D design.
+# for a 1D metagrating.
 
 import meep as mp
 import meep.adjoint as mpa
@@ -30,7 +30,7 @@
 # periodic boundary conditions
 k_point = mp.Vector3()
 
-# plane of incidence is XZ
+# plane of incidence is XY
 P_pol = True
 src_cmpt = mp.Ex if P_pol else mp.Ez
 src_pt = mp.Vector3(0,-0.5*sy+dpml+0.5*dsub)
@@ -93,9 +93,20 @@ def mapping(x):
                     k_point=k_point,
                     eps_averaging=False)
 
-emc = mpa.EigenmodeCoefficient(sim,mp.Volume(center=mp.Vector3(0,0.5*sy-dpml),size=mp.Vector3(px,0)),
-                               mode=1,eig_parity = mp.EVEN_Z if P_pol else mp.ODD_Z,
-                               kpoint_func=lambda *not_used: kdiff)
+emc = mpa.EigenmodeCoefficient(
+    sim,
+    mp.Volume(
+        center=mp.Vector3(0, 0.5*sy - dpml),
+        size=mp.Vector3(px, 0)
+    ),
+    mode=1,
+    eig_parity=mp.EVEN_Z if P_pol else mp.ODD_Z,
+    kpoint_func=lambda *not_used: kdiff,
+    eig_vol=mp.Volume(
+        center=mp.Vector3(0, 0.5*sy - dpml),
+        size=mp.Vector3(1 / resolution, 0, 0)
+    )
+)
 ob_list = [emc]
 
 opt = mpa.OptimizationProblem(simulation=sim,objective_functions=J,objective_arguments=ob_list,
@@ -140,4 +151,4 @@ def f(v, gradient):
 
 x = np.sign(mapping(x)-0.5)/2+0.5
 x = x.astype(int)
-np.savetxt('optimized_pattern_1d.dat', x)
+np.savetxt('optimized_pattern_1d.dat', x)
diff --git a/Metagrating3D/metagrating_meep_opt_2d.py b/Metagrating3D/metagrating_meep_opt_2d.py
@@ -1,5 +1,5 @@
 # This python script is for maximizing the diffraction efficiency of the m=+1 order
-# for a 3D metagrating with a 2D design.
+# for a 2D metagrating.
 
 import meep as mp
 import meep.adjoint as mpa
@@ -95,9 +95,20 @@ def mapping(x):
                     k_point=k_point,
                     eps_averaging=False)
 
-emc = mpa.EigenmodeCoefficient(sim,mp.Volume(center=mp.Vector3(0,0,0.5*sz-dpml),size=mp.Vector3(px,py,0)),
-                               mode=1,eig_parity = mp.EVEN_Y if P_pol else mp.ODD_Y,
-                               kpoint_func=lambda *not_used: kdiff)
+emc = mpa.EigenmodeCoefficient(
+    sim,
+    mp.Volume(
+        center=mp.Vector3(0, 0, 0.5*sz - dpml),
+        size=mp.Vector3(px, py, 0)
+    ),
+    mode=1,
+    eig_parity = mp.EVEN_Y if P_pol else mp.ODD_Y,
+    kpoint_func=lambda *not_used: kdiff,
+    eig_vol=mp.Volume(
+        center=mp.Vector3(0, 0, 0.5*sz - dpml),
+        size=mp.VEctor3(1 / resolution, 1 / resolution, 0)
+    )
+)
 ob_list = [emc]
 
 opt = mpa.OptimizationProblem(simulation=sim,objective_functions=J,objective_arguments=ob_list,
@@ -150,4 +161,4 @@ def f(v, gradient):
 x = np.sign(mapping(x)-0.5)/2+0.5
 x = x.astype(int)
 x = x.reshape(Nx,Ny)
-np.savetxt('optimized_pattern_2d.dat', x)
+np.savetxt('optimized_pattern_2d.dat', x)