A simple photodetector model with two optical ports. This is a special use case of the photodetector_simple photonic model where the photodetector has two optical ports and any unabsorbed light from one port can pass through the other port. Designers can add a reflector at the second optical port to increase the overall responsivity of these devices. Note that if optical input is present at both ports then the photodetector simply adds up the photocurrent due to the inputs at the two ports.
Template: pd_c_dual_port
Photonic Model: photodetector_simple
Quality Assurance Test: photodetector_simple QA
Parameters: None.
Platform and Model Support
[[snippet||51412162291091]]
Modeling Data
The source data template for photodetector element can divided into two sections.
- For new users (continue with the following section: Basic Data Requirement)
- Advanced users (continue with section: Complete Data Requirement)
The photodetector template can be used to create a very advanced compact model for a custom photodetector. The template contains a lot of different modeling data to create an accurate model. However, not all these data need to be updated by the user. The fastest/ simplest way to modify the template data and create a custom compact model would be to only update the values of the data listed in the 'basic data requirement section' below, while all rest of the data (which is illustrated in detail in subsequent sections) can be left at their default value.
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 photodetector 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 that provides 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 input optical port |
| opt_2 | ||
| ele_an | Port definition corresponding to the anode and cathode of the photodetector. | |
| 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 at which the port is listed in a netlist. |
model_data
"model_data" is a struct with following fields:
| Field | Type | Description |
|---|---|---|
bandwidth_data |
struct |
The 3-dB cutoff frequency (Hz) of the photodetector as a function of applied bias voltage (V). The required fields are:
Note: Data must be provided for at least two bias voltages |
Idark_data |
struct |
The total dark current (A) of the photodetector as a function of bias voltage (V). The required fields are:
Note:
|
resp_data |
struct |
The responsivity (A/W) of the photodetector as a function of frequency (Hz). The required fields are:
Note:
|
elec_eq_ckt_data (optional) |
struct with fields described in elec_eq_ckt_data | Data required for modeling the electrical equivalent circuit for accurate electro-optic simulations. For more information on the electrical equivalent circuit, see Electrical equivalent circuit details in the photonic model page. |
| opt_passthrough (optional) | number | Passthrough optical transmission in dB. The same value is used to calculate the unabsorbed input signal from opt_1 exiting through opt_2 and vice versa. Used in models with dual optical port only. If not provided then the model uses a default value of -2000 dB (i.e., no passthrough optical signal at the opposite ports). |
elec_eq_ckt_data
| Field | Type | Description |
|---|---|---|
| Rj | number | Series resistance (Ω) of the photodetector. |
| Cj_data | number/matrix |
Junction capacitance (F) of the photodetector, provided in either one of the following forms: 1. A single value containing the junction capacitance. 2. An struct containing junction capacitance as a function of bias voltage, and the required fields are:
|
| Rp | number | Parasitic contact resistance (Ω) of the photodetector |
| Cp | number | Parasitic capacitance (F) from the metal pads |
Complete data requirement (for advanced users)
The complete data section provides a complete reference of data supported by the photodetector model including the basic required data described in the previous section. The description of all the fields in the photodetector 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||47131902268179]]
| opt_2 (optional) | struct with fields described in table below | Port definition corresponding to the second input optical port |
| ele_an_2 (optional) | Port definition corresponding to the second anode of the photodetector. |
Each struct above consists of following fields:
[[snippet||11549759363603]]
parameters
"parameters" is a struct with following fields:
[[snippet||12153804332691]]
Each struct above consists of following fields:
[[snippet||11720299494931]]
model_data
"model_data" is a struct with following fields:
[[snippet||12154138198803]]
[[snippet||47132200893843]]
QA
"QA" is a struct with following fields:
[[snippet||47132287463059]]