Optical single bus ring resonator
Keywords
optical, bidirectional
Ports
Name | Type |
---|---|
port 1 | Optical Signal |
port 2 | Optical Signal |
Properties
General Properties
Name | Default value | Default unit | Range |
---|---|---|---|
name Defines the name of the element. |
Single Bus Ring Resonator | - | - |
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). |
Single Bus Ring Resonator | - | - |
description A brief description of the elements functionality. |
Optical single bus ring resonator | - | - |
prefix Defines the element name prefix. |
RING | - | - |
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 the waveguide. A Taylor expansion around this frequency is performed to estimate the propagation transfer function of the waveguide. |
193.1 |
THz* *std. unit is Hz |
(0, +∞) |
length The length of the waveguide. |
10e-006 | m | [0, +∞) |
Waveguide/Mode 1 Properties
Name | Default value | Default unit | Range |
---|---|---|---|
orthogonal identifier 1 The first identifier used to track an orthogonal mode of an optical waveguide. For most waveguide, two orthogonal identifiers '1' and '2' are available (with the default labels 'TE' and 'TM' respectively). |
1 | - | [1, +∞) |
label 1 The label corresponding to the first orthogonal identifier. |
TE | - | - |
loss 1 The loss corresponding to the first orthogonal identifier. |
0 | dB/m | [0, +∞) |
effective index 1 The effective index corresponding to the first orthogonal identifier. |
1 | - | (-∞, +∞) |
group index 1 The group index coefficient corresponding to the first orthogonal identifier. |
1 | - | [0, +∞) |
dispersion 1 The dispersion coefficient corresponding to the first orthogonal identifier. |
0 | s/m/m | (-∞, +∞) |
dispersion slope 1 Defines the dispersion slope corresponding to the first orthogonal identifier. |
0 | s/m^2/m | (-∞, +∞) |
coupling coefficient 1 The power coupling coefficient corresponding to the first orthogonal identifier. |
0.5 | - | [0, 1] |
Waveguide/Mode 2 Properties
Name | Default value | Default unit | Range |
---|---|---|---|
orthogonal identifier 2 The second identifier used to track an orthogonal mode of an optical waveguide. For most waveguide, two orthogonal identifiers '1' and '2' are available (with the default labels 'TE' and 'TM' respectively). |
2 | - | [1, +∞) |
label 2 The label corresponding to the second orthogonal identifier. |
TM | - | - |
loss 2 The loss corresponding to the second orthogonal identifier. |
0 | dB/m | [0, +∞) |
effective index 2 The effective index corresponding to the second orthogonal identifier. |
1 | - | (-∞, +∞) |
group index 2 The group index coefficient corresponding to the second orthogonal identifier. |
1 | - | [0, +∞) |
dispersion 2 The dispersion coefficient corresponding to the second orthogonal identifier. |
0 | s/m/m | (-∞, +∞) |
dispersion slope 2 Defines the dispersion slope corresponding to the second orthogonal identifier. |
0 | s/m^2/m | (-∞, +∞) |
coupling coefficient 2 The power coupling coefficient corresponding to the second orthogonal identifier. |
0.5 | - | [0, 1] |
Waveguide/Mode 1/Thermal Properties
Name | Default value | Default unit | Range |
---|---|---|---|
effective index temperature sensitivity 1 Defines the ratio between effective index variation and temperature. |
0 | /K | (-∞, +∞) |
excess loss temperature sensitivity 1 Defines the ratio between loss variation and temperature. |
0 | /K | [0, +∞) |
Waveguide/Mode 2/Thermal Properties
Name | Default value | Default unit | Range |
---|---|---|---|
effective index temperature sensitivity 2 Defines the ratio between effective index variation and temperature. |
0 | /K | (-∞, +∞) |
excess loss temperature sensitivity 2 Defines the ratio between loss variation and temperature. |
0 | /K | [0, +∞) |
Thermal Properties
Name | Default value | Default unit | Range |
---|---|---|---|
thermal effects Defines whether or not to enable thermal effects. |
false | - | [true, false] |
temperature Defines the temperature. |
%temperature% | K | (-∞, +∞) |
nominal temperature Defines the nominal temperature where temperature sensitivity values are measured. |
300 | K | (-∞, +∞) |
thermal fill factor The waveguide length ratio affected by the thermal effects. |
1 | - | [0, 1] |
Numerical/Digital Filter Properties
Name | Default value | Default unit | Range |
---|---|---|---|
single tap filter Defines whether or not to use a single tap digital filter to represent the element transfer function in time domain. |
false | - | [true, false] |
number of taps estimation Defines the method used to estimate the number of taps of the digital filter. |
fit tolerance | - | [disabled, fit tolerance, group delay |
filter fit tolerance Defines the mean square error for the fitting function. |
0.001 | - | (0, 1) |
window function Defines the window type for the digital filter. |
rectangular | - | [rectangular, hamming, hanning |
number of fir taps Defines the number of coefficients for digital filter. |
256 | - | [1, +∞) |
maximum number of fir taps Defines the number of coefficients for digital filter. |
4096 | - | [1, +∞) |
filter delay Defines the time delay equivalent to a number of coefficients for digital filter. |
0 | s | [0, +∞) |
initialize filter taps Defines whether to use the initial input signal to initialize filter state values or to set them to zero values. |
false | - | [true, false] |
Diagnostic Properties
Name | Default value | Default unit | Range |
---|---|---|---|
run diagnostic Enables the frequency response of the designed filter implementation and the ideal frequency response to be generated as results. |
false | - | [true, false] |
diagnostic size The number of frequency points used when calculating the filter frequency response. |
1024 | - | [2, +∞) |
Results
Name | Description |
---|---|
diagnostic/response #/transmission | The complex transmission vs. frequency corresponding to the ideal and designed filter. |
diagnostic/response #/gain | The gain vs. frequency corresponding to the ideal and designed filter. |
diagnostic/response #/error | Mean square error comparing the frequency response of the designed filter implementation with the ideal frequency response. |
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Implementation Details
An optical ring resonator consists of a waveguide which looped back on itself, and the resonance occurs when the circumference of the ring is exactly a multiple number of wavelengths. Hence a ring resonator supports multiple resonances, and the free spectral range (FSR) depends on the resonator's circumference.
Commonly there is an adjacent waveguide bus beside the ring resonator to couple the light out. For a single bus ring resonator, the transmission spectrum shows dips around the resonance wavelengths, hence it behaves like a spectral filter. In this way, the single bus ring resonator can be used in optical communication systems, especially in wavelength division multiplexing (WDM) systems. Please see the WDM application example for more information.
Given the propagation constant β and the circumference L of the ring, the working principle of the single bus ring resonator can be deducted by the following equations:
$$ \varphi = \beta \cdot L $$
$$ \frac{E_{pass}}{E_{input}} = e^{j(\pi+\varphi)} \frac{a-t e^{-i \varphi}}{1-t a e^{i \varphi}} $$
$$ \frac{T_{pass}}{T_{input}}=\frac{a^{2}-2 a t \cdot \cos \varphi+t^{2}}{1-2 a t \cdot \cos \varphi+(a t)^{2}} $$
where t is the self-coupling coefficient and theoretically, t2 + k2 = 1; a is the amplitude transmission for single pass, which consists of propagation loss in the ring and coupling loss.
The figures below show the sweep results of the phase delay and gain/loss for the system in the example file single_bus_ring_resonator.icp. The gain/loss are measured for 0.1 coupling coefficient and the phase delays are measured for the coupling coefficients sweep through the values indicated in the plot.
References
[1] Bogaerts, Wim, et al. "Silicon microring resonators." Laser & Photonics Reviews 6.1 (2012): 47-73.