48 research outputs found
Hybrid III-V/Si distributed-feedback laser based on adhesive bonding
A hybrid evanescently coupled III-V/silicon distributed-feedback laser with an integrated monitor photodiode, based on adhesive divinyl siloxane-benzocyclobutene bonding and emitting at 1310 nm, is presented. An output power of similar to 2.85 mW is obtained in a continuous wave regime at 10 degrees C. The threshold current is 20 mA and a sidemode suppression ratio of 45 dB is demonstrated. Optical feedback is provided via corrugations on top of the silicon rib waveguide, while a specially developed bonding procedure yields 40-nm-thick adhesive bonding layers, enabling efficient evanescent coupling
Evaluation of the two-photon exchange diagrams for the electron configuration in Li-like ions
We present ab initio calculations of the complete gauge-invariant set of
two-photon exchange graphs for the electron configuration in
Li-like ions. These calculations are an important step towards the precise
theoretical determination of the - transition energy in the
framework of QED.Comment: 17 pages, 6 figure
Screened self-energy correction to the 2p3/2-2s transition energy in Li-like ions
We present an ab initio calculation of the screened self-energy correction
for (1s)^2 2p3/2 and (1s)^2 2s states of Li-like ions with nuclear charge
numbers in the range Z = 12-100. The evaluation is carried out to all orders in
the nuclear-strength parameter Z \alpha. This investigation concludes our
calculations of all two-electron QED corrections for the 2p3/2-2s transition
energy in Li-like ions and thus considerably improves theoretical predictions
for this transition for high-Z ions
Hybrid silicon evanescent approach to optical interconnects
We discuss the recently developed hybrid silicon evanescent platform (HSEP), and its application as a promising candidate for optical interconnects in silicon. A number of key discrete components and a wafer-scale integration process are reviewed. The motivation behind this work is to realize silicon-based photonic integrated circuits possessing unique advantages of III–V materials and silicon-on-insulator waveguides simultaneously through a complementary metal-oxide semiconductor fabrication process. Electrically pumped hybrid silicon distributed feedback and distributed Bragg reflector lasers with integrated hybrid silicon photodetectors are demonstrated coupled to SOI waveguides, serving as the reliable on-chip single-frequency light sources. For the external signal processing, Mach–Zehnder interferometer modulators are demonstrated, showing a resistance-capacitance-limited, 3 dB electrical bandwidth up to 8 GHz and a modulation efficiency of 1.5 V mm. The successful implementation of quantum well intermixing technique opens up the possibility to realize multiple III–V bandgaps in this platform. Sampled grating DBR devices integrated with electroabsorption modulators (EAM) are fabricated, where the bandgaps in gain, mirror, and EAM regions are 1520, 1440 and 1480 nm, respectively. The high-temperature operation characteristics of the HSEP are studied experimentally and theoretically. An overall characteristic temperature (T
0) of 51°C, an above threshold characteristic temperature (T
1) of 100°C, and a thermal impedance (Z
T
) of 41.8°C/W, which agrees with the theoretical prediction of 43.5°C/W, are extracted from the Fabry–Perot devices. Scaling this platform to larger dimensions is demonstrated up to 150 mm wafer diameter. A vertical outgassing channel design is developed to accomplish high-quality III–V epitaxial transfer to silicon in a timely and dimension-independent fashion
Підхід до створення інформаційної системи для ведення обліку присутності за допомогою камери в режимі реального часу
Мета та завдання дослідження, наведеного в даній роботі, – створити інформаційну систему моніторингу відвідуваності студентів вищих навчальних закладів, за допомогою камери в режимі реального часу. Дана розробка (штучний інтелект) була створена за допомогою спрощення та вдосконалення окремих процесів розпізнавання обличь за рахунок машинного навчання з застосуванням алгоритмів для обробки та підготовки даних. Завдання розроблюваної системи – це моніторинг відвідуваності студентів вищих навчальних закладів, яка буде вести облік присутності студентів за допомогою live-камери. Об’єкт дослідження – процес розпізнавання обличь на відео. Предмет дослідження – методи та моделі розпізнавання обличь на відео.
Бібл. 9, іл. 6, табл.