1.7. Test your knowledge

In this application example, you have mainly executed code and modified some parameters. Below, you will find assignments that you can try to complete using the principles explained above to consolidate your knowledge.

1.7.1. Task 1: Compact Four-Way demultiplexer

Goal: Reduce the footprint of the four-Way demultiplexer with FSR of 50 nm at 1.55 \(\mu m\) center wavelength as much as possible while keeping crosstalk below 10dB.

Hints:

  1. Have a smarter placement of the Mux2’s
  2. Use fewer directional couplers in the Mux2.
  3. Flip the directional couplers to use shorter ones.

Start by:

  1. Make a copy of mux2.py and mux4.py (e.g. mux2yourname.py, mux4yourname.py).
  2. Modify mux2yourname.py and mux4yourname.py to achieve your goal.

You will have to adapt the import statements of the Mux2 in the Mux4.

Best solution so far:

\(96 \mu m \text{ X } 106 \mu m\). If you can do better send your solution to info@lucedaphotonics.com

../../../_images/mux4_folded.png ../../../_images/S_total5.png

1.7.2. Task 2: Maximize the extinction (and insertion loss) ratio of Mux2

Goal: Achieve -40 dB of extinction loss of a 2-way Mux2 at a center wavelength of 1.55 \(\mu m\) and an FSR of 25 nm in the smallest possible space.

Hints:

  1. Use higher order Mux2’s
  2. Stack different Mux2’s to increase the extinction ratio.
  3. Have a smarter placement of the Mux2’s.

Start by:

  1. Make a copy of mux2.py
  2. Modify mux2.py to achieve your goal.

Best solution so far:

\(200 \mu m \text{ X } 104 \mu m\). If you can do better send your solution to info@lucedaphotonics.com.

../../../_images/mux2staged.png ../../../_images/S_total6.png