FiberCouplerCurvedGrating

class picazzo3.fibcoup.curved.cell.FiberCouplerCurvedGrating

Class for the definition of periodic curved fiber grating couplers with a focal point that fit in a box.

Parameters
grating: PCell

grating of this fiber coupler

inclination: float

out-of-plane angle of the grating coupler

start_trace_template: PCell and _WaveguideTemplate

start waveguide for the socket waveguide (narrow side)

wide_trace_template: PCell and _WaveguideTemplate

end waveguide for the socket waveguide (broad side)

socket: PCell and WgSocket

socket of the fiber coupler

name: String that contains only ISO/IEC 8859-1 (extended ASCII py3) or pure ASCII (py2) characters

The unique name of the pcell

Views

class Layout

This class generates a fiber grating coupler composed of a curved fiber grating with a LinearTransitionSocket. The origin of the coordinate system of the component is placed where the center of the fiber facet is assumed to have maximal coupling efficiency. This also the location of the vertical port vertical_in.

The grating lines generated by this class have the following properties.

1. All the grating lines have a shared focus point that is the east focus point of all the ellipses. The focus point has to be on the x-axis. The location of the focus is set by focal_distance_x and will be located east of the origin.

2. The first grating line will be drawn a distance min_x from the focus point. So if min_x = 10, this means that the distance between the focus point and the first grating line will exactly be 10. By default, min_x is set to:

3. All the grating lines are periodic in the x-direction with period_x. This means that the distance between the intersections of grating lines with the x-axis is equal to period_x.

4. All the grating lines are periodic in the y direction with period_y. This means that the distance between the intersections grating lines with the y-axis is equal to period_y.

  1. The radius of the first ellipse in the y-direction is set be start_radius_y.

  2. The radius of the first ellipse in the x-direction is automatically calculated and therefore locked.

7. All the grating lines fit in a box with width set by box_width that is symmetrically set along the x-axis. For example if box_width is set to 10.0 all the grating lines will go from y=-5.0 to y=5.0.

8. The width of all the grating lines is set by fill_factor. A fill factor of 1 makes that the line width is a wide as the period. A fill factor of 0 makes sets the line_width to 0.

The socket is a LinearTransitionSocket transitioning from the start_trace_template to wide_trace_template. start_trace_template is the template seen at the focal point while wide_trace_template is the one seen at the location of the vertical port ``vertical_in`. The length of the transition socket_length is therefore locked and automatically set to the focal_distance_x.

To extend the taper beyond the focal point you can use the property socket_extension which will automatically prolong the taper with the length socket_extension The default value of extension is chosen such that entire grating fits in the socket.

Parameters
fill_factor: float and fraction

Fill factor used to calculate the trench widths. 0 means no trench a all and 1 means that the trench covers the entire period

grating_transformation: GenericNoDistortTransform
process: ProcessLayer

default process used for the grating

purpose:
socket_extension: float and Real, number and number >= 0

extension of the wide side of the socket, asymmetric with respect to the specified center. By default this is calculated such that the entire grating fits in the socket with a margin of TECH.IO.FIBCOUP.CURVED.DEFAULT_SOCKET_MARGIN_FROM_GRATING

spread_angle: float

Angle in degrees of the far field radiation field of the socket.By default this is set to be equal to the angle of the taper that is set by its length and the width of the core of input and output waveguides.

min_x: float and number > 0

Minimum distance from the first line to the focus. By default it is set to the focal distance.

n_o_lines: int and number > 0

Number of lines in the grating. By default this number is chosen so that the curves fit in the box width.

period_x: float and number > 0

Period in the x direction.

focal_distance_x: float

Distance between the vertical port of the grating and the focal point. By default this is TECH.IO.FIBCOUP.CURVED.GRATING.FOCAL_DISTANCE.

period_y: float and number > 0

Period in the y direction. By default equal to period_x

start_radius_y: float and number > 0

Starting radius in the y direction. By default this is set to start_period_x

box_width: float and number > 0

Width of the box used that contains the grating.

socket_straight_extension: Coord2 and number >= 0

tuple: straight extension at start and end of socket

socket_transformation: GenericNoDistortTransform
view_name: String that contains only alphanumeric characters from the ASCII set or contains _$. ASCII set is extended on PY3.

The name of the view

Other Parameters
centers: locked
ellipse_radii_x: locked
ellipse_radii_y: locked
socket_length: locked
line_widths: locked

Line width of the grating coupler

start_radius_x: locked
focal_point: Coord2, locked

Coordinate of the east focus point shared by all ellipses. The y coordinate of the focuspoint has to be zero

end_angles: locked
start_angles: locked

Examples

Basic use:

# Example demonstrating the basic use of the FiberGratingCoupler.
from technologies import silicon_photonics  # noqa: F401
from ipkiss3 import all as i3

from picazzo3.fibcoup.curved import FiberCouplerCurvedGrating
from picazzo3.traces.wire_wg import WireWaveguideTemplate

# Creating the wire templates for the socket.
start_wg_tmpl = WireWaveguideTemplate()
start_wg_tmpl.Layout(core_width=0.5, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 0.5)
end_wg_tmpl = WireWaveguideTemplate()
end_wg_tmpl.Layout(core_width=17.0, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 17.0)

fc_cell = FiberCouplerCurvedGrating(start_trace_template=start_wg_tmpl, wide_trace_template=end_wg_tmpl)

fc_layout = fc_cell.Layout(
    period_x=0.8, focal_distance_x=20.0  # We with a period of 0.8
)  # We use a focal distance of 20.0

fc_layout.visualize(annotate=True)
../../../../_images/picazzo3-fibcoup-curved-cell-FiberCouplerCurvedGrating-1.png

Changing the n_o_lines and where to place the first line:

# Example demonstrating how to change the length of the grating coupler using n_o_lines
# and how to set the location of the first grating line using min_x
from technologies import silicon_photonics  # noqa: F401
from ipkiss3 import all as i3

from picazzo3.fibcoup.curved import FiberCouplerCurvedGrating
from picazzo3.traces.wire_wg import WireWaveguideTemplate

# Creating the wire templates for the socket.
start_wg_tmpl = WireWaveguideTemplate()
start_wg_tmpl.Layout(core_width=0.5, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 0.5)
end_wg_tmpl = WireWaveguideTemplate()
end_wg_tmpl.Layout(core_width=17.0, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 17.0)

fc_cell = FiberCouplerCurvedGrating(start_trace_template=start_wg_tmpl, wide_trace_template=end_wg_tmpl)

fc_layout = fc_cell.Layout(
    period_x=0.8,  # We with a period of 0.8
    focal_distance_x=20.0,  # We use a focal distance of 20.0
    n_o_lines=30,  # We set the number of lines to 30
    min_x=10.0,  # We set the first line at 10.
)

fc_layout.visualize(annotate=True)
../../../../_images/picazzo3-fibcoup-curved-cell-FiberCouplerCurvedGrating-2.png

Changing the box_width:

# Example demonstrating how to change the box_width.
from technologies import silicon_photonics  # noqa: F401
from ipkiss3 import all as i3

from picazzo3.fibcoup.curved import FiberCouplerCurvedGrating
from picazzo3.traces.wire_wg import WireWaveguideTemplate

# Creating the wire templates for the socket.
start_wg_tmpl = WireWaveguideTemplate()
start_wg_tmpl.Layout(core_width=0.5, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 0.5)
end_wg_tmpl = WireWaveguideTemplate()
end_wg_tmpl.Layout(core_width=17.0, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 17.0)

fc_cell = FiberCouplerCurvedGrating(start_trace_template=start_wg_tmpl, wide_trace_template=end_wg_tmpl)

fc_layout = fc_cell.Layout(
    period_x=0.8,  # We with a period of 0.8
    focal_distance_x=20.0,  # We use a focal distance of 20.0.
    n_o_lines=30,  # We set the number of lines to 30.
    min_x=10.0,  # We set the first line at 10.
    box_width=40.0,  # All the lines will be contained between -20 and 20
)

fc_layout.visualize(annotate=True)
../../../../_images/picazzo3-fibcoup-curved-cell-FiberCouplerCurvedGrating-3.png

Changing the fill_factor to set the line width:

# Example demonstrating how to change the fill_factor.
from technologies import silicon_photonics  # noqa: F401
from ipkiss3 import all as i3

from picazzo3.fibcoup.curved import FiberCouplerCurvedGrating
from picazzo3.traces.wire_wg import WireWaveguideTemplate

# Creating the wire templates for the socket.
start_wg_tmpl = WireWaveguideTemplate()
start_wg_tmpl.Layout(core_width=0.5, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 0.5)
end_wg_tmpl = WireWaveguideTemplate()
end_wg_tmpl.Layout(core_width=17.0, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 17.0)

fc_cell = FiberCouplerCurvedGrating(start_trace_template=start_wg_tmpl, wide_trace_template=end_wg_tmpl)

fc_layout = fc_cell.Layout(
    period_x=0.8,  # We with a period of 0.8
    focal_distance_x=20.0,  # We use a focal distance of 20.0.
    n_o_lines=30,  # We set the number of lines to 30.
    min_x=10.0,  # We set the first line at 10.
    fill_factor=0.2,  # Here we set the fill factor to 0.2 meaning that lines will be 0.2 * period_x thick
)

fc_layout.visualize(annotate=True)
../../../../_images/picazzo3-fibcoup-curved-cell-FiberCouplerCurvedGrating-4.png

Changing the start radii in the y direction:

# Example that illustrates the degrees of freedom at your disposal concerning the
# periodicity and radii of the gratings in the y direction. You have more freedom in
# y direction since the focus is in the x-axis.

from technologies import silicon_photonics  # noqa: F401
from ipkiss3 import all as i3

from picazzo3.fibcoup.curved import FiberCouplerCurvedGrating
from picazzo3.traces.wire_wg import WireWaveguideTemplate

# Creating the wire templates for the socket.
start_wg_tmpl = WireWaveguideTemplate()
start_wg_tmpl.Layout(core_width=0.5, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 0.5)
end_wg_tmpl = WireWaveguideTemplate()
end_wg_tmpl.Layout(core_width=17.0, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 17.0)

fc_cell = FiberCouplerCurvedGrating(start_trace_template=start_wg_tmpl, wide_trace_template=end_wg_tmpl)

fc_layout = fc_cell.Layout(
    focal_distance_x=20.0,  # We use a focal distance of 20.0.
    n_o_lines=30,  # We use 30 lines.
    period_x=0.8,  # We with a period of 0.8
    period_y=0.5,  # period has to be smaller than the period in the x direction
    start_radius_y=3.0,  # Start_radius_y has to be smaller than min_x
    fill_factor=0.2,  # Fill factor of 0.2
    min_x=10.0,  # First line at 10.0
)

fc_layout.visualize(annotate=True)
../../../../_images/picazzo3-fibcoup-curved-cell-FiberCouplerCurvedGrating-5.png

Changing the socket extensions:

# Example demonstrating how to change the socket_extension.
from technologies import silicon_photonics  # noqa: F401
from ipkiss3 import all as i3

from picazzo3.fibcoup.curved import FiberCouplerCurvedGrating
from picazzo3.traces.wire_wg import WireWaveguideTemplate

# Creating the wire templates for the socket.
start_wg_tmpl = WireWaveguideTemplate()
start_wg_tmpl.Layout(core_width=0.5, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 0.5)
end_wg_tmpl = WireWaveguideTemplate()
end_wg_tmpl.Layout(core_width=17.0, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 17.0)

fc_cell = FiberCouplerCurvedGrating(start_trace_template=start_wg_tmpl, wide_trace_template=end_wg_tmpl)

fc_layout = fc_cell.Layout(
    period_x=0.8,  # We with a period of 0.8
    focal_distance_x=20.0,  # We use a focal distance of 20.0.
    n_o_lines=30,  # We set the number of lines to 30.
    min_x=10.0,  # We set the first line at 10.
    box_width=40.0,  # All the lines will be contained between -20 and 20
    socket_extension=30.0,  # A socket extension will of 30.0 will be added
)

fc_layout.visualize(annotate=True)
../../../../_images/picazzo3-fibcoup-curved-cell-FiberCouplerCurvedGrating-6.png

Changing the straight socket extensions:

# Example demonstrating how to change the socket_straight_extensions.
from technologies import silicon_photonics  # noqa: F401
from ipkiss3 import all as i3

from picazzo3.fibcoup.curved import FiberCouplerCurvedGrating
from picazzo3.traces.wire_wg import WireWaveguideTemplate

# Creating the wire templates for the socket.
start_wg_tmpl = WireWaveguideTemplate()
start_wg_tmpl.Layout(core_width=0.5, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 0.5)
end_wg_tmpl = WireWaveguideTemplate()
end_wg_tmpl.Layout(core_width=17.0, cladding_width=2 * i3.TECH.WG.TRENCH_WIDTH + 17.0)

fc_cell = FiberCouplerCurvedGrating(start_trace_template=start_wg_tmpl, wide_trace_template=end_wg_tmpl)

fc_layout = fc_cell.Layout(
    period_x=0.8,  # We with a period of 0.8
    focal_distance_x=20.0,  # We use a focal distance of 20.0.
    n_o_lines=30,  # We set the number of lines to 30.
    min_x=10.0,  # We set the first line at 10.
    box_width=40.0,
    # A straight extension of 10.0 will be added at the
    # narrow side and 5.0 at the wide part of the socket.
    socket_straight_extension=(10.0, 5.0),
)

fc_layout.visualize(annotate=True)
../../../../_images/picazzo3-fibcoup-curved-cell-FiberCouplerCurvedGrating-7.png