Project 1 Design

submissions/KLayout Python/EBeam_AndrewB_Cavities.py

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+'''
+Scripted layout for ring resonators using SiEPIC-Tools
+in the SiEPIC-EBeam-PDK "EBeam" technology
+
+by Lukas Chrostowski, 2023
+
+Use instructions:
+
+Run in Python, e.g., VSCode
+
+pip install required packages:
+ - klayout, SiEPIC, siepic_ebeam_pdk, numpy
+
+'''
+
+designer_name = 'AndrewB'
+top_cell_name = 'EBeam_%s_Cavities1' % designer_name
+export_type = 'PCell'  # static: for fabrication, PCell: include PCells in file
+
+import pya
+from pya import *
+
+import SiEPIC
+from SiEPIC._globals import Python_Env
+from SiEPIC.scripts import zoom_out, export_layout
+from SiEPIC.verification import layout_check
+import os
+import numpy
+
+if Python_Env == 'Script':
+    try:
+        # For external Python mode, when installed using pip install siepic_ebeam_pdk
+        import siepic_ebeam_pdk
+    except:
+        # Load the PDK from a folder, e.g, GitHub, when running externally from the KLayout Application
+        import os, sys
+        path_GitHub = os.path.expanduser('~/Documents/GitHub/')
+        sys.path.insert(0,os.path.join(path_GitHub, 'SiEPIC_EBeam_PDK/klayout'))
+        import siepic_ebeam_pdk
+
+tech_name = 'EBeam'
+
+# Example layout function
+def cavities():
+
+    # Import functions from SiEPIC-Tools
+    from SiEPIC.extend import to_itype
+    from SiEPIC.scripts import connect_cell, connect_pins_with_waveguide
+    from SiEPIC.utils.layout import new_layout, floorplan
+
+    # Create a layout for testing a double-bus ring resonator.
+    # uses:
+    #  - the SiEPIC EBeam Library
+    # creates the layout in the presently selected cell
+    # deletes everything first
+
+    # Configure parameter sweep  
+    pol = 'TE'
+    sweep_n = [45, 60, 75]
+    period = 0.27
+    sweep_dW = [0.05]
+    # cavity_length = 50_000
+    cavity_lengths = [50_000, 100_000, 150_000]
+    taper_length_um = 20
+
+    '''
+    Create a new layout using the EBeam technology,
+    with a top cell
+    and Draw the floor plan
+    '''    
+    cell, ly = new_layout(tech_name, top_cell_name, GUI=True, overwrite = True)
+    floorplan(cell, 605e3, 410e3)
+
+    if SiEPIC.__version__ < '0.5.1':
+        raise Exception("Errors", "This example requires SiEPIC-Tools version 0.5.1 or greater.")
+
+    # Layer mapping:
+    LayerSiN = ly.layer(ly.TECHNOLOGY['Si'])
+    fpLayerN = cell.layout().layer(ly.TECHNOLOGY['FloorPlan'])
+    TextLayerN = cell.layout().layer(ly.TECHNOLOGY['Text'])
+
+
+    # Create a sub-cell for our Ring resonator layout
+    top_cell = cell
+    dbu = ly.dbu
+    cell = cell.layout().create_cell("Cavities")
+    t = Trans(Trans.R0, 40 / dbu, 12 / dbu)
+
+    # place the cell in the top cell
+    top_cell.insert(CellInstArray(cell.cell_index(), t))
+
+    # Import cell from the SiEPIC EBeam Library
+    cell_ebeam_gc = ly.create_cell("GC_%s_1310_8degOxide_BB" % pol, "EBeam")
+    # get the length of the grating coupler from the cell
+    gc_length = cell_ebeam_gc.bbox().width()*dbu
+    # spacing of the fibre array to be used for testing
+    GC_pitch = 127
+
+    #cell_terminator = ly.create_cell("ebeam_terminator_te1310", "EBeam")
+
+    cell_taper_cavity = ly.create_cell('ebeam_taper_te1550', "EBeam", {
+        'wg_width1': 0.350,
+        'wg_width2': 2.000,
+        'wg_length': taper_length_um})
+
+    cell_y = ly.create_cell('ebeam_y_1310', 'EBeam_Beta')
+
+    # Loop through the parameter sweep
+    #for i in range(len(sweep_gap)):
+    # for i in range(len(sweep_period)):
+    for index_1, n in enumerate(sweep_n):
+        for index_2, dW in enumerate(sweep_dW):
+            for index_3, cavity_length in enumerate(cavity_lengths):
+
+                p = period
+
+                i = index_1 + index_2 + index_3
+                # place layout at location:
+                if i==0:
+                    x=0
+                else:
+                    # next device is placed at the right-most element + length of the grating coupler
+                    x = inst_bragg1.bbox().right*dbu + gc_length + 10
+
+                # get the parameters
+                # n = sweep_n[i]
+                # p = sweep_period[i]
+
+                # Grating couplers, Ports 0, 1, 2, 3 (from the bottom up)
+                instGCs = []
+                for j in range(0,4):
+                    if j == 1:
+                        instGCs.append(0)
+                        continue; # Don't create the 2nd GC
+
+                    t = Trans(Trans.R0, to_itype(x,dbu), j*127/dbu + 3/dbu)
+                    instGCs.append( cell.insert(CellInstArray(cell_ebeam_gc.cell_index(), t)) )
+
+                # Label for automated measurements, laser on Port 2, detectors on Ports 1, 3, 4
+                t = Trans(Trans.R90, to_itype(x,dbu), to_itype(GC_pitch*2,dbu))
+                # text = Text ("opt_in_%s_1310_device_%s_FPPeriodn%sp%s" % (pol.upper(), designer_name,n,int(round(p*1000))), t)
+                text = Text(f"opt_in_{designer_name}_1310_device_n{n}_dW{int(dW*100)}_L{int(cavity_length/10_000)}", t)
+                text.halign = 1
+                cell.shapes(TextLayerN).insert(text).text_size = 5/dbu
+
+                #cell_splitter = ly.create_cell('ebeam_splitter_swg_assist_te1310', "EBeam")
+
+                cell_bragg = ly.create_cell('ebeam_bragg_te1550', "EBeam", {
+                  'number_of_periods': n,
+                  'grating_period': p,
+                  'corrugation_width': dW,
+                  'wg_width': 0.350,
+                  'sinusoidal': True})
+
+                if i == 0:
+                    inst_y = connect_cell(instGCs[2], 'opt1', cell_y, 'opt1')
+                    first_GC2 = instGCs[2]
+                else:
+                    inst_y = connect_cell(first_GC2, 'opt1', cell_y, 'opt1')
+
+                inst_y.transform(Trans(Trans.R90, 270000 + x*1000, 200000))
+
+                inst_bragg1 = connect_cell(inst_y, 'opt1', cell_bragg, 'pin1')
+
+                inst_taper_cavity1 = connect_cell(inst_bragg1, 'pin2', cell_taper_cavity, 'pin1')
+
+                inst_taper_cavity2 = connect_cell(inst_taper_cavity1, 'pin1', cell_taper_cavity, 'pin1')
+                inst_taper_cavity2.transform(Trans(0, -cavity_length))
+
+                inst_bragg2 = connect_cell(inst_taper_cavity2, 'pin1', cell_bragg, 'pin2')
+
+                # Ring resonator from directional coupler PCells
+                #cell_dc = ly.create_cell("ebeam_dc_halfring_straight", "EBeam", { "r": r, "w": wg_width, "g": g, "bustype": 0 } )
+                #y_ring = GC_pitch*3/2
+                # first directional coupler
+                #t1 = Trans(Trans.R270, to_itype(x+wg_bend_radius, dbu), to_itype(y_ring, dbu))
+                #inst_dc1 = cell.insert(CellInstArray(cell_dc.cell_index(), t1))
+                # add 2nd directional coupler, snapped to the first one
+                #inst_dc2 = connect_cell(inst_dc1, 'pin2', cell_dc, 'pin4')
+
+                connect_pins_with_waveguide(inst_taper_cavity1, 'pin2', inst_taper_cavity2, 'pin2', waveguide_type='Multimode Strip TE 1550 nm, w=2000 nm')
+
+                # Create paths for waveguides, with the type defined in WAVEGUIDES.xml in the PDK
+                waveguide_type='Strip TE 1310 nm, w=350 nm'
+
+                # GC1 to bottom-left of ring pin3
+                #connect_pins_with_waveguide(instGCs[1], 'opt1', inst_bragg1, 'pin2', waveguide_type=waveguide_type)
+
+                # GC2 to top-left of ring pin1
+                connect_pins_with_waveguide(instGCs[2], 'opt1', inst_y, 'opt2', waveguide_type=waveguide_type)
+
+                # GC0 to top-right of ring
+                connect_pins_with_waveguide(instGCs[0], 'opt1', inst_bragg2, 'pin1', waveguide_type=waveguide_type)
+
+                # GC3 to bottom-right of ring
+                connect_pins_with_waveguide(instGCs[3], 'opt1', inst_y, 'opt3', waveguide_type=waveguide_type)
+
+    # Introduce an error, to demonstrate the Functional Verification
+    # inst_dc2.transform(Trans(1000,-1000))
+
+    return ly, cell
+
+ly, cell = cavities()
+
+# Zoom out
+zoom_out(cell)
+
+# Save
+path = os.path.dirname(os.path.realpath(__file__))
+filename = os.path.splitext(os.path.basename(__file__))[0]
+file_out = export_layout(cell, path, filename, relative_path = '..', format='oas', screenshot=False)
+
+print('layout script done')