As promised I will try and write a little bit about research too!
So here goes.
At OWTNM 2014 in Nice I met a researcher from Aston University in Birmingham. They use fs laser inscription to write waveguides in Lithium Niobate (the spot exposed by the laser has a lower index than Lithium Niobate. Therefore by writing several spots around a central “core” area, it is possible to create low index “holes” around a core, and guide light in this core by total internal reflection).
We got talking and now we are trying to collaborate. The idea is that I use my experience with the spiral design to optimize a spiral waveguide that offers sufficient guidance with low loss and changes the dispersion. While Mykhalo will make the waveguide and test it.
The challenge here is that the index contrast created is very small: ~-.015 to -.02. With such a low index contrast changing the total dispersion (by making the waveguide dispersion large) is quite tough. Since the index contrast is low, the field is not easily confined to a small spot and the effective index of the guided mode remains very close to the material refractive index.
So I have to find a way to alter the dispersion appreciably. Secondly Mykhalo wants the results before end of September! So its quick time work.
And I am loving it.
It is really exciting to work on something real-life and challenging. Even more so because there is the possibility of seeing my own design being fabricated!