30 research outputs found
Performance of Rhode Island Red, Black Australorp, and Naked Neck crossbreds under alternative production systems
The effects of the production system, breed cross, and their interaction on performance, egg quality, and hatching traits were evaluated. Rhode Island Red and Black Australorp were crossed with Naked Neck chickens (first generation RNN, and BNN, respectively). These crosses were mated among themselves and crossed to produce four crossbreds: RR (RNN x RNN), BB (BNN x BNN), RB (RNN x BNN), and BR (BNN x RNN). Thirty-six pullets and 9 cockerels from each crossbred were maintained in three production systems: the aviary system (AV), conventional cages (CC), and enriched cages (EC). Thus there were 48 pullets and 12 cockerels in each production system. Bodyweight, egg production percentage, and egg weight were highest in EC, followed by CC and AV. Higher egg weight, egg surface area, and egg volume were also observed in EC compared with CC and AV. Fertility and hatchability were higher and early embryonic mortality was lower in AV than in EC and CC. Bodyweight, egg production percentage, egg weight, egg volume, and surface area were higher for RB and BR than for BB and RR. Fertility and hatchability were similar for RB and BR. RR was similar to BR, but lower than RB. BB had the lowest fertility and hatchability. Thus, chickens in EC performed better than in the other systems, except that hatching traits were better in AV. RB and BR performed better than BB and RR.Key words: breed crosses, chicken, egg quality, hatchabilit
Lithium niobate photonic-crystal electro-optic modulator
Modern advanced photonic integrated circuits require dense integration of
high-speed electro-optic functional elements on a compact chip that consumes
only moderate power. Energy efficiency, operation speed, and device dimension
are thus crucial metrics underlying almost all current developments of photonic
signal processing units. Recently, thin-film lithium niobate (LN) emerges as a
promising platform for photonic integrated circuits. Here we make an important
step towards miniaturizing functional components on this platform, reporting
probably the smallest high-speed LN electro-optic modulators, based upon
photonic crystal nanobeam resonators. The devices exhibit a significant tuning
efficiency up to 1.98 GHz/V, a broad modulation bandwidth of 17.5 GHz, while
with a tiny electro-optic modal volume of only 0.58 . The
modulators enable efficient electro-optic driving of high-Q photonic cavity
modes in both adiabatic and non-adiabatic regimes, and allow us to achieve
electro-optic switching at 11 Gb/s with a bit-switching energy as low as 22 fJ.
The demonstration of energy efficient and high-speed electro-optic modulation
at the wavelength scale paves a crucial foundation for realizing large-scale LN
photonic integrated circuits that are of immense importance for broad
applications in data communication, microwave photonics, and quantum photonics
Chip-scale Simulations in a Quantum-correlated Synthetic Space
An efficient simulator for quantum systems is one of the original goals for
the efforts to develop a quantum computer [1]. In recent years, synthetic
dimension in photonics [2] have emerged as a potentially powerful approach for
simulation that is free from the constraint of geometric dimensionality. Here
we demonstrate a quantum-correlated synthetic crystal, based upon a
coherently-controlled broadband quantum frequency comb produced in a chip-scale
dynamically modulated lithium niobate microresonator. The time-frequency
entanglement inherent with the comb modes significantly extends the
dimensionality of the synthetic space, creating a massive nearly 400 x 400
synthetic lattice with electrically-controlled tunability. With such a system,
we are able to utilize the evolution of quantum correlations between entangled
photons to perform a series of simulations, demonstrating quantum random walks,
Bloch oscillations, and multi-level Rabi oscillations in the time and frequency
correlation space. The device combines the simplicity of monolithic
nanophotonic architecture, high dimensionality of a quantum-correlated
synthetic space, and on-chip coherent control, which opens up an avenue towards
chip-scale implementation of large-scale analog quantum simulation and
computation [1,3,4] in the time-frequency domain.Comment: 21 pages, 14 figures (including supplementary materials
Electrically empowered microcomb laser
Optical frequency comb underpins a wide range of applications from
communication, metrology, to sensing. Its development on a chip-scale platform
-- so called soliton microcomb -- provides a promising path towards system
miniaturization and functionality integration via photonic integrated circuit
(PIC) technology. Although extensively explored in recent years, challenges
remain in key aspects of microcomb such as complex soliton initialization, high
threshold, low power efficiency, and limited comb reconfigurability. Here we
present an on-chip laser that directly outputs microcomb and resolves all these
challenges, with a distinctive mechanism created from synergetic interaction
among resonant electro-optic effect, optical Kerr effect, and optical gain
inside the laser cavity. Realized with integration between a III-V gain chip
and a thin-film lithium niobate (TFLN) PIC, the laser is able to directly emit
mode-locked microcomb on demand with robust turnkey operation inherently built
in, with individual comb linewidth down to 600 Hz, whole-comb frequency tuning
rate exceeding Hz/s, and 100% utilization of optical
power fully contributing to comb generation. The demonstrated approach unifies
architecture and operation simplicity, high-speed reconfigurability, and
multifunctional capability enabled by TFLN PIC, opening up a great avenue
towards on-demand generation of mode-locked microcomb that is expected to have
profound impact on broad applications
Integrated Pockels Laser
The development of integrated semiconductor lasers has miniaturized
traditional bulky laser systems, enabling a wide range of photonic
applications. A progression from pure III-V based lasers to III-V/external
cavity structures has harnessed low-loss waveguides in different material
systems, leading to significant improvements in laser coherence and stability.
Despite these successes, however, key functions remain absent. In this work, we
address a critical missing function by integrating the Pockels effect into a
semiconductor laser. Using a hybrid integrated III-V/Lithium Niobate structure,
we demonstrate several essential capabilities that have not existed in previous
integrated lasers. These include a record-high frequency modulation speed of 2
exahertz/s (2.010 Hz/s) and fast switching at 50 MHz, both of
which are made possible by integration of the electro-optic effect. Moreover,
the device co-lases at infrared and visible frequencies via the second-harmonic
frequency conversion process, the first such integrated multi-color laser.
Combined with its narrow linewidth and wide tunability, this new type of
integrated laser holds promise for many applications including LiDAR, microwave
photonics, atomic physics, and AR/VR