Toolkit Documentation¶

Set of helper functions that make it easier to manipulate and work with subclasses defined in components module

class picwriter.toolkit.Component(name, *args)¶

Super class for all objects created in PICwriter. This class handles rotations, naming, etc. for all components, so that writing python code for new cells requires less overhead. Component is a wrapper around gdspy Cell objects.

Args:

name (string): The name prefix to be used for these

Keyword Args:

angle (float): Angle in radians (between 0 and pi/2) at which the waveguide bends towards the coupling region. Default=pi/6.

add(element, origin=(0, 0), rotation=0.0, x_reflection=False)¶: Add a reference to an element or list of elements to the cell associated with this component

picwriter.toolkit.add(top_cell, component_cell, center=(0, 0), x_reflection=False)¶

First creates a CellReference to subcell, then adds this to topcell at location center.

Args:

top_cell (gdspy.Cell): Cell being added to
component_cell (gdspy.Cell): Cell of the component being added

Keyword Args:

port (tuple): location for the subcell to be added
direction (string): Direction that the component will point towards, can be of type ‘NORTH’, ‘WEST’, ‘SOUTH’, ‘EAST’, OR an angle (float, in radians). Defaults to ‘EAST’ (zero degrees of rotation).

Returns:

None

picwriter.toolkit.build_mask(cell, wgt, final_layer=None, final_datatype=None)¶

Builds the appropriate mask according to the resist specifications and fabrication type. Does this by applying a boolean ‘XOR’ or ‘AND’ operation on the waveguide and clad masks.

Args:

cell (gdspy.Cell): Cell with components. Final mask is placed in this cell.
wgt (WaveguideTemplate): Waveguide template containing the resist information, and layers/datatypes for the waveguides and cladding.

Keyword Args:

final_layer (int): layer to place the mask on (defaults to wgt.clad_layer + 1)
final_datatype (int): datatype to place the mask on (defaults to 0)

Returns:

None

picwriter.toolkit.build_waveguide_polygon(func, wg_width, start_direction, end_direction, start_val=0, end_val=1, grid=0.001)¶

Args:

func (function): Function that takes a single (floating point) argument, and returns a (x,y) tuple.
wg_width (float): Waveguide width
num_pts (int): Number of points that make up the waveguide path
start_direction (float): Starting direction of the path, in radians.
end_direction (float): End direction of the path, in radians.

Keyword Args:

start_val (float): Starting value (argument passed to func). Defaults to 0.
end_val (float): Ending value (argument passed to func). Defaults to 1.
grid (float): Grid resolution used to determine when curve length has converged. Guarantees that polygon formed by the points results in no more than a grid/2.0 error from the true position. Defaults to 0.001

Returns:

Two lists, one for each edge of the waveguide.

picwriter.toolkit.dist(pt1, pt2)¶

Given two cardinal points, returns the distance between the two.

Args:

pt1 (tuple): Point 1
pt2 (tuple): Point 2

Returns:

float Distance

Example:

import picwriter.toolkit as tk
print(tk.dist((0, 0), (100, 100)))

The above prints 141.42135623730951

picwriter.toolkit.flip_direction(direction)¶

Returns the opposite of direction, where each direction is either 'NORTH', 'WEST', 'SOUTH', or 'EAST'

Args:

direction (direction): Direction to be flipped
pt2 (tuple): Point 2

Returns:

direction ('NORTH', 'WEST', 'SOUTH', or 'EAST')

picwriter.toolkit.get_angle(pt1, pt2)¶

Given two cardinal points, returns the corresponding angle in radians. Must be an integer multiple of pi/2.

Args:

pt1 (tuple): Point 1
pt2 (tuple): Point 2

Returns:

float Angle (integer multiple of pi/2)

Example:

import picwriter.toolkit as tk
print(tk.get_angle((0, 0), (0, 100)))

The above prints 1.5707963267948966

picwriter.toolkit.get_curve_length(func, start, end, grid=0.001)¶

Returns the length (in microns) of a curve defined by the function func on the interval [start, end]

Args:

func (function): Function that takes a single (floating point) argument, and returns a (x,y) tuple.
start (float): Starting value (argument passed to func).
end (float): Ending value (argument passed to func).

Keyword Args:

grid (float): Grid resolution used to determine when curve length has converged. Defaults to 0.001.

Returns:

float Length

picwriter.toolkit.get_direction(pt1, pt2)¶

Returns a cardinal direction ('NORTH', 'WEST', 'SOUTH', and 'EAST') that corresponds to a cartesian point pt1 (tuple), pointing TOWARDS a second point `pt2

Args:

pt1 (tuple): Point 1
pt2 (tuple): Point 2

Returns:

string ('NORTH', 'WEST', 'SOUTH', and 'EAST')

Example:

import picwriter.toolkit as tk
tk.get_direction((0,0), (-100,0))

The above prints ‘WEST’

picwriter.toolkit.get_exact_angle(pt1, pt2)¶

Given two cardinal points, returns the corresponding angle in radians.

Args:

pt1 (tuple): Point 1
pt2 (tuple): Point 2

Returns:

float Angle (in radians)

Example:

import picwriter.toolkit as tk
print(tk.get_angle((0, 0), (100, 100)))

The above prints 0.785398163

picwriter.toolkit.get_keys(cell)¶

Returns a list of the keys available in a portlist, such as ‘input’, ‘output’, ‘top_output’, etc. Only works for picwriter components.

Args:

cell (gdspy.Cell): Cell from which to get get the portlist

Returns:

List of portlist keys corresponding to ‘cell’.

picwriter.toolkit.get_trace_length(trace, wgt)¶

Returns the total length of a curved waveguide trace.

Args:

trace (list): tracelist of (x,y) points all specifying 90 degree angles. Assumes there are no bends on the first and last point.
wgt (WaveguideTemplate): template for the waveguide, the bend_radius of which is used to compute the length of the curved section.

Returns:

float corresponding to the length of the waveguide trace

picwriter.toolkit.get_turn(dir1, dir2)¶

Returns an angle (+pi/2 or -pi/2) corresponding to the CW or CCW turns that takes you from direction dir1 to dir2, where each direction is either 'NORTH', 'WEST', 'SOUTH', or 'EAST'

Args:

dir1 (direction): Point 1
pt2 (tuple): Point 2

Returns:

float (+pi/2 or -pi/2)

picwriter.toolkit.normalize_angle(angle)¶

Returns the angle (in radians) between -pi and +pi that corresponds to the input angle

Args:

angle (float): Angle to normalize

Returns:

float Angle

picwriter.toolkit.reset_database()¶: Resets the gdspy library, and resets the CURRENT_CELLS and CURRENT_CELL_NAMES dicts

picwriter.toolkit.translate_point(pt, length, direction, height=0.0)¶

Returns the point (tuple) corresponding to pt translated by distance length in direction direction where each direction is either 'NORTH', 'WEST', 'SOUTH', or 'EAST'

Args:

pt (tuple): Starting point
length (float): Distance to move in direction
direction (direction): Direction to move in

Keyword Args:

height (float): Distance to move perpendicular to direction. Defaults to 0.

Returns:

point, tuple (x, y)