A nominal variable optical attenuator model. This device is assumed to be composed of an active region in the middle, connected to the input/output ports by passive transitions and waveguides. For a diagram of the expected layout, see the Internal Model Diagram in photonic model page.
Template: voa_te_c
Photonic Model: phase_shifter_electrical
Quality Assurance Test: phase_shifter_electrical QA
Supported Parameters: length of the active region.
Platform and Model Support
[[snippet||51412210500371]]
Modeling Data
The source data template for a Variable Optical Attenuator can divided into two sections.
- For new users (continue with the following section: Basic Data Requirement)
- For advanced users (continue with section: Complete Data Requirement)
In order to get started and add a custom variable optical attenuator element into the compact model library (CML), a user only needs to edit the data listed in the ‘basic data requirement section’ below, while all other data (i.e. the advanced element data) can be left as is.
Note: Advanced users please jump start with Complete Data Requirement (for advanced users) section.
Basic data requirement section (for new users)
The basic or minimum data required to build the variable optical attenuator model is described below.
general
"general" is a struct with following fields:
| Field | Type | Description |
|---|---|---|
| description | string | A string containing a brief description of the model, which will be displayed to the end user. |
| notes | cell |
A cell array providing model notes which will be displayed to the end user. Each element of the cell is a struct with the fields:
|
ports
"ports" is a struct with following fields:
| Field | Type | Description |
|---|---|---|
| opt_1 | struct with fields described in table below | Port definition corresponding to the optical ports |
| opt_2 | ||
| ele_an | Port definition corresponding to the electrical cathode and anode | |
| ele_cat |
Each struct above consists of following fields:
| Field | Type | Description |
|---|---|---|
| name | string | The name of the port, which will be visible to the end user. This name should be consistent with the name that will be used for netlisting. |
| dir | string | The directionality of the port, either "Input", "Output", or "Bidirectional" |
| pos | string | The side of the model which the port will be displayed on, either "Left", "Right", "Top", or "Bottom" |
| order | number | The order in which the port is listed in a netlist. |
parameters
"parameters" is a struct with following fields:
| Field | Type | Description |
|---|---|---|
wg_length |
struct with fields described in table below | The length of the active waveguide region. |
Each struct above consists of following fields:
| Field | Type | Description |
|---|---|---|
default |
number | The nominal value of the parameter in SI unit. |
min |
number | Minimum allowed value if the visible_to_user is set to True. |
max |
number | Maximum allowed value if the visible_to_user is set to True. |
model_data
"model_data" is a struct with following fields:
| Field | Type | Description |
|---|---|---|
mode_data |
cell |
M x 1 cell array where M is the number of modes. Each element of the cell is a struct with fields:
Note: This model only supports up to two modes. |
IV_data |
struct |
The current data, as a function of voltage and temperature, in the form of a struct with the following fields:
Note: At least two bias points must be provided. |
FOMs
"FOMs" is a struct with fields below. This data is required for CML Compiler to run quality-assurance tests on the final model. It is also optionally used by CML Compiler to fine-tune the internal model to provide the expected behavior.
If the source physical data provided for the model is not consistent with the figures of merit (FOMs) provided (meaning the actual FOM values resulting from physical parameters differ from provided FOM data), the model can tune the provided physical data to match the FOMs to the provided values. For more information, see Tuning Active Compact Models.
| Field | Type | Description |
|---|---|---|
IL |
struct with fields described in table below |
The overall insertion loss (dB) of the phase shifter at zero bias.
|
Attn_eff |
struct with fields described in table below | Attenuation efficiency (dB/mA) of the optical attenuator, as defined for voltage range described by "ref1" and "ref2" in the struct. |
Each struct above consists of following fields:
Note: The following variables can be provided as a 2x1 matrix if more than one mode is supported.
| Field | Type | Description |
|---|---|---|
tuning |
boolean | A flag to enable or disable FOM tuning. |
min |
number | Minimum allowed value in SI unit if visible_to_user is set to True. |
max |
number | Maximum allowed value in SI unit if visible_to_user is set to True. |
| ref1 (if applicable) | number | Point(s) at which the nominal FOM were measured. This parameter can be voltage or power data points depending on the FOM definition. |
|
ref2 (if applicable) |
number |
Complete data requirement (for advanced users)
The advanced data section provides a complete reference of data supported by the variable optical attenuator model including the basic required data described in the previous section.
The description of all the fields in the source data template are described below.
general
"general" is a struct with following fields:
[[snippet||11549514081811]]
ports
"ports" is a struct with following fields:
[[snippet||12092461714963]]
Each struct above consists of following fields:
[[snippet||11549759363603]]
parameters
"parameters" is a struct with following fields:
[[snippet||12092500096659]]
Each struct above consists of following fields:
[[snippet||11720299494931]]
model_data
"model_data" is a struct with following fields:
[[snippet||12115391452563]]
bandwidth_data (optional) |
struct |
The 3-dB cutoff frequency (Hz) of the electrical modulator as a function of bias voltage (V). The required fields are:
Note:
|
IV_data |
struct |
The current data, as a function of voltage and temperature, in the form of a struct with the following fields:
Note: At least two bias points must be provided. |
| waveguide_data | struct with fields described in waveguide_data table | Data required for modeling the waveguide sections. |
waveguide_data
Note: The fields are only required for waveguide sections with non-zero length. See Internal Model Diagram in photonic model page for a diagram showing the role of each section.
| Field | Type | Description |
|---|---|---|
wavelength |
number | Center wavelength (m) of the band for which the mode properties are provided. |
temperature |
number | Temperature (K) for which the mode properties below are provided. |
waveguide_passive_right |
struct with fields described in table below
|
Mode properties for modeling the right and left passive waveguide sections |
waveguide_passive_left | ||
waveguide_transition_right |
Mode properties for modeling the right and left passive to electrically active transition waveguide sections | |
waveguide_transition_left | ||
waveguide_phase_shifter |
Mode properties for modeling the electrical phase shifter waveguide section at 0 V bias |
Structs listing mode properties for different waveguide sections consist of following fields:
[[snippet||11653970537235]]
FOMs
"FOMs" is a struct with fields below. This data is required for CML Compiler to run quality-assurance tests on the final model. It is also optionally used by CML Compiler to fine-tune the internal model to provide the expected behavior.
If the source physical data provided for the model is not consistent with the figures of merit (FOMs) provided (meaning the actual FOM values resulting from physical parameters differ from provided FOM data), the model can tune the provided physical data to match the FOMs to the provided values. For more information, see Tuning Active Compact Models.
[[snippet||12116770242323]]
Attn_eff |
struct with fields described in table below | Attenuation efficiency (dB/mA) of the optical attenuator, as defined for voltage range described by "ref1" and "ref2" in the struct. |
Each struct above consists of following fields:
Note: The following variables can be provided as a 2x1 matrix if more than one mode is supported.
[[snippet||11653867902995]]
QA
"QA" is a struct with following fields:
[[snippet||12117860577811]]