Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-efficiency and broadband electro-optic frequency combs enabled by
  coupled micro-resonators   Developments in integrated photonics have led to stable, compact, and
broadband comb generators that support a wide range of applications. Current
on-chip comb generators, however, are still limited by low optical pump-to-comb
conversion efficiencies. Here, we demonstrate an integrated electro-optic
frequency comb with a conversion efficiency of 30% and an optical bandwidth of
132 nm, featuring a 100-times higher conversion efficiency and 2.2-times
broader optical bandwidth compared with previous state-of-the-art integrated
electro-optic combs. We further show that, enabled by the high efficiency, the
device acts as an on-chip femtosecond pulse source (336 fs pulse duration),
which is important for applications in nonlinear optics, sensing, and
computing. As an example, in the ultra-fast and high-power regime, we
demonstrate the observation of a combined EO-\chi^(3) nonlinear frequency comb.
Our device paves the way for practical optical frequency comb generators
enabling energy-efficient computing, communication, and metrology, and provides
a platform to investigate new regimes of optical physics that simultaneously
involve multiple nonlinearities.

8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom