Silicon photonics is becoming the leading technology for photonic integrated circuits (PICs) due to large-scale integration, low cost, and high-volume productions enabled by complementary ...metal-oxide-semiconductor (CMOS) fabrication process. Thanks to various material and optical characteristics of crystalline silicon, the silicon-on-insulator platform has become the dominant material platform for silicon photonics. Meanwhile, monolithic or heterogeneous integration of other materials on silicon photonic chips, including the silicon nitride (SiN)-on-insulator platform and the III-V-on-silicon platform, are under rapid developments to enhance the functionalities of silicon photonics. Among the myriad of silicon photonic structures for passive and active components, integrated microresonators are promising for a broad range of applications due to their strong resonance field enhancement, narrowband wavelength selectivity, and compact footprints. In this paper, we review the state of the art and our perspectives on emerging technologies based on integrated silicon photonic microresonators in the technology domains of intradatacenter optical interconnects, integrated nonlinear and quantum photonics, and lab-on-a-chip optical biosensing. We specifically review recent progress and our original work in SOI microring-based crossbar switch fabrics; III-V-on-silicon microresonator lasers; silicon-based microresonator nonlinear and quantum sources; and SiN microresonator-based optical biosensors.
The development of facile and efficient polymerizations toward functional polymers with unique structures and attractive properties is of great academic and industrial significance. Here we develop a ...straightforward C-H-activated polyspiroannulation route to in situ generate photoresponsive spiro-polymers with complex structures. The palladium(II)-catalyzed stepwise polyspiroannulations of free naphthols and internal diynes proceed efficiently in dimethylsulfoxide at 120 °C without the constraint of apparent stoichiometric balance in monomers. A series of functional polymers with multisubstituted spiro-segments and absolute molecular weights of up to 39,000 are produced in high yields (up to 99%). The obtained spiro-polymers can be readily fabricated into different well-resolved fluorescent photopatterns with both turn-off and turn-on modes based on their photoinduced fluorescence change. Taking advantage of their photoresponsive refractive index, we successfully apply the polymer thin films in integrated silicon photonics techniques and achieve the permanent modification of resonance wavelengths of microring resonators by UV irradiation.
The rapid evolution of generative artificial intelligence (AI) and virtual reality (VR) technologies are revolutionising various fields, including education and gaming industries. However, studies on ...how to enhance immersive game-based learning with AI and VR technologies remain scant. Given this, the article presents the creation of “LearningverseVR,” an immersive game-based learning platform developed using generative AI and VR technologies, which is based on “Learningverse,” a metaverse platform developed by the lead author and her research team. The “LearningverseVR” platform uses Unity as the client and Python, Flask and MySQL as the backend. Unity's multiplayer service provides multiplayer online functionality, supporting learners to engage in immersive and interactive learning activities. The design framework of the platform consists of two main components: Game-based learning with generative AI and immersion with VR technologies. First, generative AI is used to create NPCs with diverse personalities and life backgrounds, and enable learners to interact with NPCs without scripted dialogues, creating an interactive and immersive game-based learning environment. Secondly, such a learning experience is enhanced by leveraging the Large Language Model (LLM) ecosystem with VR technology. The creation of the “LearningverseVR” platform provides novel perspectives on digital game-based learning.
•The rapid evolution of generative AI and VR technologies are revolutionising digital game-based learning.•Studies on how to enhance immersive game-based learning with AI and VR technologies remain scant.•The article presents the creation of “LearningverseVR,” an immersive game-based learning platform.•In the VR industry, this research adopted generative AI technology to enhance user experiences in augmented metaverses.•The creation of the “LearningverseVR” platform provides novel perspectives on digital game-based learning.
Natural heritage is formed in the process of interaction between man and nature and society, etc. The conservation of natural heritage has attracted widespread attention from the whole society. Based ...on system dynamics theory, the article investigates the mechanism of benefit distribution among the government, enterprises and indigenous people in natural heritage reserves by constructing a four-group evolutionary game model, and then explores the best cooperation strategy among the government, indigenous people and natural heritage tourism development enterprises. The results of this study show that: (1) The best results for natural heritage conservation are achieved when government, business and indigenous people take active steps together. (2) As the probability of government incentives increases, the probability of indigenous people choosing to cooperate increases. (3) As government oversight increases, companies will be more likely to choose rational development. (4) The choice of reasonable development by enterprises will positively push the indigenous people to choose the cooperative strategy. Finally, based on the above findings, the paper proposes corresponding policy recommendations.
Polarization-entangled photon pair sources exhibiting nonlocal quantum correlations are crucial to developments of quantum computing, quantum communications, quantum cryptography, and quantum sensing ...technologies. On-chip polarization entanglement generation thus constitutes one enabling component for integrated quantum photonic circuits. Here, we present to our knowledge the first polarization-entangled photon pair sources in a silicon nitride platform for integrated quantum photonic circuits. We demonstrate the generation of a polarization-entangled state by adopting a configuration comprising dual microring resonators, with nearly degenerate transverse electric and transverse magnetic polarized cavity resonances for the two resonators coupled in series to a common bus waveguide. We measure two-photon interference and quantum state tomography to characterize the polarization entanglement of the generated state and to reconstruct the density matrix. Our experiments reveal a visibility of 96.4% ± 3.1% and of 86.7% ± 3.2% with the | H ⟩ and | V ⟩ bases, respectively (and a visibility of 89.4% ± 6.6% and 81.3% ± 7.3% with the | D ⟩ and | A ⟩ bases), and a fidelity of ∼75.7% from the tomographic reconstructed density matrix.
We develop a stress-released stoichiometric silicon nitride (Si
3
N
4
) fabrication process for dispersion-engineered integrated silicon photonics. To relax the high tensile stress of a thick Si
3
N
...4
film grown by low-pressure chemical vapor deposition (LPCVD) process, we grow the film in two steps and introduce a conventional dense stress-release pattern onto a ∼400nm-thick Si
3
N
4
film in between the two steps. Our pattern helps minimize crack formation by releasing the stress of the film along high-symmetry periodic modulation directions and helps stop cracks from propagating. We demonstrate a nearly crack-free ∼830nm-thick Si
3
N
4
film on a 4” silicon wafer. Our Si
3
N
4
photonic platform enables dispersion-engineered, waveguide-coupled microring and microdisk resonators, with cavity sizes of up to a millimeter. Specifically, our 115µm-radius microring exhibits an intrinsic quality (Q)-factor of ∼2.0×10
6
for the TM
00
mode and our 575µm-radius microdisk demonstrates an intrinsic Q of ∼4.0×10
6
for TM modes in 1550nm wavelengths.
The silicon nitride (Si
3
N
4
) platform, demonstrating a moderate third-order optical nonlinearity and a low optical loss compared with those of silicon, is suitable for integrated quantum photonic ...circuits. However, it is challenging to develop a crack-free, wafer-scale, thick Si
3
N
4
platform in a single deposition run using a subtractive complementary metal-oxide-semiconductor (CMOS)-compatible fabrication process suitable for dispersion-engineered quantum light sources. In this paper, we demonstrate our unique subtractive fabrication process by introducing a stress-release pattern prior to the single Si
3
N
4
film deposition. Our Si
3
N
4
platform enables 950 nm-thick and 8 μm-wide microring resonators supporting whispering-gallery modes for quantum light sources at 1550 nm wavelengths. We report a high photon-pair generation rate of ∼1.03 MHz/mW
2
, with a high spectral brightness of ∼5×10
6
pairs/s/mW
2
/GHz. We demonstrate the first heralded single-photon measurement on the Si
3
N
4
platform, which exhibits a high quality of conditional self-correlation
g
H
(2)
(0) of 0.008 ± 0.003.
Heterogeneously integrated lasers comprising an active layer (e.g., III-V semiconductor multiple quantum wells) bonded on top of a passive silicon photonic layer on the silicon-on-insulator substrate ...have been proposed and studied as one of the light sources for optical interconnects. However, the buried oxide layer and the bonding layer inhibit heat dissipation and compromise the laser's performance. In this paper, we adopt a thermal shunt design that provides a direct path for the heat generated in the gain layer to reach the silicon substrate. Using finite element modeling, we illustrate the effectiveness of our thermal shunt designs. We improve the thermal resistance from 1241 K/W without an integrated thermal shunt to 296 K/W with an integrated p-electrode thermal shunt. We have also identified the parameters that give the optimal thermal performance.
Electrically pumped and directly modulated microlasers comprising a III-V semiconductor multi-quantum well (MQW) heterogeneously integrated on a silicon photonic chip are potentially a key building ...block for datacenter optical interconnects. We adopt a microspiral disk cavity in the silicon photonic layer, with a seamlessly coupled silicon waveguide at the microspiral notch, for unidirectional laser output-coupling characteristics. We integrate a ring-shaped electrode on top of the III-V gain layer in order to preferentially inject into a group of whispering-gallery-like modes for improved energy efficiency and mode selection. In this paper, we report multi-mode lasing under both pulsed and continuous injection at room temperature. The threshold current density is typically a few kA/cm 2 .
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