Represent now on the central part of the picture the primary elements of the logotype to be, applying the same
Ellipse Tool (U).
Fill 0% on the layers.
Blending Options-Gradient Overlay
Gradient’s parameters:

Using the previous instrument, we have to represent the next layer of black color.

Continue:
Fill 0% on the layers.
Blending Options-Gradient Overlay
Gradient’s parameters: