11 research outputs found
Quasi-phase-matching with Spontaneous Domain Inversion in an Integrated Lithium Niobate Micro-racetrack Resonator
Quasi-phase-matching (QPM) technology is the most popular and significant
method to achieve efficient nonlinear frequency conversion. The realization of
periodically poling to achieve QPM in photonic integrated circuits (PICs) is a
challenging issue for the requirement of CMOS compatible and large-scale
fabrication. Here we realize a spontaneous periodical domain inversion without
poling but by dispersion engineering and designing the orientation of the
crystal due to the circular propagation of light waves in an integrated lithium
niobate micro-racetrack resonator (MRR). The QPM second harmonic generation
(SHG) with a normalized conversion efficiency of 2.25/W (169th-order QPM)
has been achieved in the high-quality factor resonator of with
the straight waveguide (TE mode) of ultra-low propagation loss of
0.0022dB/cm. The efficiency can be further enhanced by using a first-order QPM,
and the bandwidth can be made broader by employing a shorter interaction length
for photonics and quantum optics. The configurable spontaneous
quasi-phase-matching lithium niobate MRR on X-cut thin-film lithium niobate on
insulator (LNOI) provides a significant on-chip integrated platform for other
optical parametric processes
Along the Giantâs Footprints: Bama China
When McDonaldâs entered Chinese market in 1989, Bama Company, a key supplier of
McDonaldâs deserts, followed to explore this potential high-volume bakery goods
kingdom in Asia. Having been influenced by western culture since the economic reform
in the 1980s, Chinese people, especially the young generation, love to enrich their daily
diet with western food. Along with American fast food booming in China, bakery
products, such as cakes, cookies, and other deserts are also well accepted by consumers.
This case introduces how Bama grows its international market by following its giant
client. While maintaining its long term partnership with McDonaldâs, Bama also
develops other clients in the fast food chain in this unfamiliar yet exciting world. Bama
China further seeks more expansion and explores larger growth in the Asian-Pacific
region to develop bakery markets. This case study discusses several options for the future
of Bama China
Experimental study on the application of air-source heat pump in a warm-temperate extreme-arid-desert climate zone
Clean and low-carbon heating methods are vigorously promoted in China under a carbon peak and carbon neutrality background. The application of air-source heat pump system (ASHP) technology has become a research hotspot as a clean and low-carbon heating method. This paper investigated the performance of an ASHP applied in Hotan, Xinjiang, China, categorized as a warm-temperate extreme-arid-desert climate (WT-EADC) zone. The actual performance of an air-source heat pump heating system with radiant floor heating (ASHP-RF) was tested experimentally using a WT-EADC zone. The system performance of the low-temperature and high-humidity climate (LTHHC), typical climate (TC), and high-temperature and low-humidity climate (HTLHC) was thoroughly examined. Results show that the system performances of the LTHHC, TC, and, HTLHC differ significantly. The average coefficient of performance (COP) values of the system under these conditions were 2.13, 2.24, and 2.46, respectively. The COP of the system increased initially with increasing ambient temperature and decreased with increasing ambient relative humidity. During the operation of the ASHP-RF, there was an ambient relative humidity corresponding to the optimal efficiency. The experimental results demonstrated that the ASHP-RF completely met the heating demand of buildings under a warm-temperate extreme-arid-desert climate, demonstrating the advantages of high efficiency and exhibiting broad-application prospects