21,755 research outputs found
Integrated all-optical logic discriminators based on plasmonic bandgap engineering
Optical computing uses photons as information carriers, opening up the
possibility for ultrahigh-speed and ultrawide-band information processing.
Integrated all-optical logic devices are indispensible core components of
optical computing systems. However, up to now, little experimental progress has
been made in nanoscale all-optical logic discriminators, which have the
function of discriminating and encoding incident light signals according to
wavelength. Here, we report a strategy to realize a nanoscale all-optical logic
discriminator based on plasmonic bandgap engineering in a planar plasmonic
microstructure. Light signals falling within different operating wavelength
ranges are differentiated and endowed with different logic state encodings.
Compared with values previously reported, the operating bandwidth is enlarged
by one order of magnitude. Also the SPP light source is integrated with the
logic device while retaining its ultracompact size. This opens up a way to
construct on-chip all-optical information processors and artificial
intelligence systems.Comment: 4 figures 201
Ultrawide-band Unidirectional Surface Plasmon Polariton Launchers
Plasmonic devices and circuits, bridging the gap between integrated photonic
and microelectronic technology, are promising candidates to realize on-chip
ultrawide-band and ultrahigh-speed information processing. Unfortunately, the
wideband surface plasmon source, one of the most important core components of
integrated plasmonic circuits, is still unavailable up to now. This has
seriously restricted the practical applications of plasmonic circuits. Here, we
report an ultrawide-band unidirectional surface plasmon polariton launcher with
high launching efficiency ratio and large extinction ratio, realized by
combining plasmonic bandgap engineering and linear interference effect. This
device offers excellent performances over an ultrabroad wavelength range from
690 to 900 nm, together with a high average launching efficiency ratio of 1.25,
large average extinction ratio of 30 dB, and ultracompact lateral dimension of
less than 4 um. Compared with previous reports, the operating bandwidth is
enlarged 210 folds, while the largest launching efficiency ratio, largest
extinction ratio, and small feature size are maintained simultaneously. This
provides a strategy for constructing on-chip surface plasmon source, and also
paving the way for the study of integrated plasmonic circuits.Comment: 4 figure
Exploration of the Non-normal Students’ Attitude to Taking Part in the Teacher Qualification Examination in China
As the teacher qualification examination has been extensively spread in China in recent years, a "national examination fever" is rising among non-normal students. A large number of non-normal college students have obtained the teacher certification by taking the qualification exam. It is found that there are all kinds of attitudes to the students’ participating in this exam. Firstly, they once had to choose a non-normal major on account of different reasons, although they expect to be teachers. Secondly, they hold a blind attitude that all their friends take part in it. Thirdly, it is a practical way to have a job choice after graduation. Therefore, we have a responsibility to remind the students to treat the examination rationally, because it can’t ensure them the capabilities required for a qualified teacher even if they have passed three or four subjects. Meanwhile, those who participate in the exam only plan to increase the possibility of getting employed instead of genuine enthusiasm for education can hardly enjoy satisfaction and happiness. Therefore, the non-normal students should recognize and understand the true purpose of the examination and make a rational career planning. At the same time, the government needs to improve the teacher qualification examination system
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