modulates an optical signal depending on electrical signal
Keywords
electrical, optical, bidirectional
Ports
| Name | Type |
|---|---|
| modulation 1 | Electrical Signal |
| modulation 2 | Electrical Signal |
| port 1 | Optical Signal |
| port 2 | Optical Signal |
Properties
General Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
name Defines the name of the element. |
Traveling Wave Optical Modulator | - | - |
|
annotate Defines whether or not to display annotations on the schematic editor. |
true | - | [true, false] |
|
enabled Defines whether or not the element is enabled. |
true | - | [true, false] |
|
type Defines the element unique type (read only). |
Traveling Wave Optical Modulator | - | - |
|
description A brief description of the elements functionality. |
modulates an optical signal depending on electrical signal | - | - |
|
prefix Defines the element name prefix. |
OM | - | - |
|
model Defines the element model name. |
- | - | - |
|
library Defines the element location or source in the library (custom or design kit). |
- | - | - |
|
local path Defines the local path or working folder $LOCAL for the element. |
- | - | - |
|
url An optional URL address pointing to the element online help. |
- | - | - |
Standard Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
configuration Defines the bidirectional or unidirectional element configuration. |
bidirectional | - | [bidirectional, unidirectional |
|
frequency Central frequency of operation. |
193.1 |
THz* *std. unit is Hz |
(0, +∞) |
|
length The interaction length of the modulator. |
1 | m | [0, +∞) |
|
input parameter Defines whether the input parameter is a table with voltage dependent values or coefficients of a polynomial function. |
table | - | [table, coefficients |
Standard/Table Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
load from file Defines whether or not to load measurements from an input file or to use the currently stored values. |
false | - | [true, false] |
|
measurement filename The file containing the measurement data. Refer to the Implementation Details section for the format expected. |
- | - | - |
|
measurement type Defines the type of measurement data. |
effective index | - | [absorption & phase, effective index |
|
measurement A matrix editor for users to read the element current modulation data values. |
<11,3> [-5, -4.5, -4,...] | - | - |
Standard/Coefficients Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
absorption coefficient a The polynomial coefficient for the absorption function. |
-0.0617 | dB/V^3/m | (-∞, +∞) |
|
absorption coefficient b The polynomial coefficient for the absorption function. |
-0.2804 | dB/V^2/m | (-∞, +∞) |
|
absorption coefficient c The polynomial coefficient for the absorption function. |
-0.6635 | dB/V/m | (-∞, +∞) |
|
absorption coefficient d The polynomial coefficient for the absorption function. |
-0.0719 | dB/m | (-∞, +∞) |
|
phase coefficient a The polynomial coefficient for the phase function. |
-0.0038 | rad/V^3/m | (-∞, +∞) |
|
phase coefficient b The polynomial coefficient for the phase function. |
0.1132 | rad/V^2/m | (-∞, +∞) |
|
phase coefficient c The polynomial coefficient for the phase function. |
-0.4825 | rad/V/m | (-∞, +∞) |
|
phase coefficient d The polynomial coefficient for the phase function. |
-0.0107 | rad/m | (-∞, +∞) |
Waveguide Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
modes List of optical mode labels supported by the element. |
TE,TM | - | - |
Enhanced Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
microwave loss Defines the microwave loss. |
0 | dB/m | [0, +∞) |
|
microwave index Defines the the microwave group index. |
3 | - | [0, +∞) |
|
optical index Defines the waveguide effective index. |
3 | - | [0, +∞) |
Numerical Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
number of steps The number of discretization steps for the waveguide. |
30 | - | [2, +∞) |
====================================
Implementation Details
Different from the Optical Modulator Measured element, the Traveling Wave Optical Modulator allows for bidirectional electro-optical simulations by providing electrical and optical bidirectional ports. The element does not rely on internal impedance properties, instead, it assumes that they will be defined externally by adding Electrical Connector elements to the circuit. User can define two types of impedance, typically the source and characteristic impedance, and the termination and characteristic impedance. It provides additional flexibilities in defining different configurations for the modulators.
The following example shows the circuit in the example file [[TWM_Modeling_Connectors.icp]]. The impedance for the electrode is defined by the Electrical Connector elements.
Using the same properties as the previous Optical Modulator Measured element with the “traveling wave’” option (Traveling Wave Modulators example), and adding connectors with the same impedance mismatch, the properties for the elements are defined as:
|
OM_2 |
CNC_1 |
CNC_2 |
|
|
|
|
The received waveform and the eye diagram for the system are the same as the previous circuits using the Optical Modulator Measured element:
|
|
|
The modulator with a larger index mismatch has a larger filtering effect thus the degradation of the signal and the eye diagram are more obvious.
Related Publications
- Hao Xu et al., "Demonstration and Characterization of High-Speed Silicon Depletion-Mode Mach–Zehnder Modulators", IEEE Journal of Selected Topics in Quantum Electronics, Vol. 20, No. 4 (2014)