Project
Introduction - Wavelength Division Multiplexing (WDM) is a common technique used in optical communication networks to increase the data capacity of a single optical fibre. By using different wavelengths, many optical communication channels can be transmitted simultaneously in an optical fibre.
In a WDM transmission system, a multiplexer is used at the transmitter to combine (multi-plex) several wavelength channels together. At the receiver, different wavelength channels are separated by a WDM demultiplexer.
Project - In this project, you will design a WDM demultiplexer based on add-drop ring resonators. The specifications of your demultiplxer depend on your student number.
Run the below code cell and enter your student number to obtain the demultiplexer specifications
In [ ]: student_number = raw_input("Enter your student number, without s, eg 1234567, then press from eeet2392.wdm_specs import *
wdm_specs(student_number)
The designed WDM demultiplexer must also satisfy the following requirements: - All ring resonators must be critically coupled. - The gap between waveguides in the directional couplers must not be smaller than 200 nm - The FSR range of all ring resonators must be at least four times the channel spacing.
Design a demultiplxer to meet the above requirements. You need to work out the length of all rings, the gap and length of all directional couplers. For this project, you can assume that the effect of the bend sections on the coupling ratios of the directional couplers is negilible.
You also must use ASP PDK in your design. You will learn about PDK in week 10. To use ASP PDK you need to import asp_silicon_photonics.technology instead to default silicon pho-tonic technology, ie import asp_silicon_photonics.technology instead of from technologies import silicon_photonics
Create a PCell for the demultiplexer. The PCell must contain the Layout view and other views required for circuit simulation.
Simulate the designed demultiplexer and plot the wavelength response of all channels and the through port. From the simulation results, determine the bandwidth, insersion loss, cross talk of each channel. Discuss what you can do to increase the bandwidth, reduce the insersion loss and reduce the cross-talk.
Attach grating couplers from the PDK to all input and output ports of the demultiplexer to form a completed demultiplexer device ready to be interfaced to optical fibres. All grating cou-plers must be spaced 50 mm apart horizontally. Generate the GDS file for your final device. Simu-late your demultiplexer with grating couplers.
Discuss the effect (if there is any) of the input and output grating couplers on the performance of the designed WDM demultiplexer.
Investigate the effects of the variation in the waveguide width on the performance of the de-signed WDM demultiplexer. Extra marks will be given if you can investigate the effect of silicon core layer thickness variation or temperature variation on the demultiplexer performance.
Attachment:- Assignment File.rar