Generic Interferometer

GenericInterferometer usage example

It is possible to define a generic interferometer with the class perceval.components.GenericInterferometer.

For instance, the following defines a triangular interferometer on 8 modes using a beam splitter and a phase shifter as base components:

>>> c = pcvl.GenericInterferometer(8,
...                                lambda i: comp.BS() // comp.PS(pcvl.P("φ%d" % i)),
...                                shape=pcvl.InterferometerShape.TRIANGLE)
>>> pcvl.pdisplay(c)
../../_images/generic-interferometer.png

GenericInterferometer code reference

enum perceval.utils._enums.InterferometerShape(value)

An enumeration.

Valid values are as follows:

RECTANGLE = <InterferometerShape.RECTANGLE: 0>

Rectangular matrix of universal 2-modes components (e.g. MZI). All paths have the same depth.

TRIANGLE = <InterferometerShape.TRIANGLE: 1>

Triangular mesh of universal 2-modes components. The top of the interferometer has max depth, the bottom mode has depth 1.

class perceval.components.generic_interferometer.GenericInterferometer(m, fun_gen, shape=InterferometerShape.RECTANGLE, depth=None, phase_shifter_fun_gen=None, phase_at_output=False, upper_component_gen=None, lower_component_gen=None, align_with_barriers=True)

Generate a generic interferometer circuit with generic elements and optional phase_shifter layer

Parameters:

  • m (int) – number of modes

  • fun_gen (Callable[[int], ACircuit]) – generator function for the building components, index is an integer allowing to generate named parameters - for instance: fun_gen=lambda idx: pcvl.BS()//(0, pcvl.PS(pcvl.P(f"phi_{idx}")))

  • shape (InterferometerShape) – The output interferometer shape (InterferometerShape.RECTANGLE or InterferometerShape.TRIANGLE)

  • depth (Optional[int]) – if None, maximal depth is \(m-1\) for rectangular shape, \(m\) for triangular shape. Can be used with \(2*m\) to reproduce [25].

  • phase_shifter_fun_gen (Optional[Callable[[int], ACircuit]]) – a function generating a phase_shifter circuit.

  • phase_at_output (bool) – if True creates a layer of phase shifters at the output of the generated interferometer else creates it in the input (default: False)

  • upper_component_gen (Optional[Callable[[int], ACircuit]]) – generator function for the building the upper component, index is an integer allowing to generate named parameters - for instance: upper_component_gen=lambda idx: pcvl.PS(pcvl.P(f"phi_upper_{idx}"))

  • lower_component_gen (Optional[Callable[[int], ACircuit]]) – generator function for the building the lower component, index is an integer allowing to generate named parameters - for instance: lower_component_gen=lambda idx: pcvl.PS(pcvl.P(f"phi_lower_{idx}"))

See [25], [16] and [66]

property mzi_depths: list[int]

Return a list of MZI depth, per mode

remove_phase_layer()

Remove the optional phase layer at the input or at the output. Does nothing if such a layer does not exist

set_identity_mode()

Set the interferometer in identity mode (i.e. photons are output on the mode they’re input)

set_param_list(param_list, top_left_pos, m)

Insert parameters value starting from a given position in the interferometer.

This method is designed to work on rectangular interferometers

Parameters:

  • param_list (list[float]) – List of numerical values for the parameters

  • top_left_pos (tuple[int, int]) – Starting position of the insertion (column#, row#). Position is handled MZI-wise (i.e. (0,0) starts inserting values on the top-left-most MZI of the interferometer whereas (1,0) starts on top of the 2nd MZI column). The optional phase layer is ignored in the position handling.

  • m (int) – Mode count on where to insert the parameter values

set_params_from_other(other, top_left_pos)

Retrieve parameter value from another interferometer

Parameters:

  • other (Circuit) – Another interferometer

  • top_left_pos (tuple[int, int]) – Starting position of the insertion. See full description in set_param_list