Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Design of Compact and Efficient Silicon Photonic Micro Antennas with
  Perfectly Vertical Emission   Compact and efficient optical antennas are fundamental components for many
applications, including high-density fiber-chip coupling and optical phased
arrays. Here we present the design of grating-based micro-antennas with
perfectly vertical emission in the 300-nm silicon-on-insulator platform. We
leverage a methodology combining adjoint optimization and machine learning
dimensionality reduction to efficiently map the multiparameter design space of
the antennas, analyse a large number of relevant performance metrics, carry out
the required multi-objective optimization, and discover high performance
designs. Using a one-step apodized grating we achieve a vertical upward
diffraction efficiency of almost 92% with a 3.6 {\mu}m-long antenna. When
coupled with an ultra-high numerical aperture fiber, the antenna exhibits a
coupling efficiency of more than 81% (-0.9 dB) and a 1-dB bandwidth of almost
158 nm. The reflection generated by the perfectly vertical antenna is smaller
than -20 dB on a 200-nm bandwidth centered at {\lambda} = 1550 nm.

29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin