arXiv subjects

Yi-Shan Lee

Publications and source records attributed to Yi-Shan Lee.

4 recordsLinked to original sources

arXiv2023

VMCML: Video and Music Matching via Cross-Modality Lifting

We propose a content-based system for matching video and background music. The system aims to address the challenges in music recommendation for new users or new music give short-form videos. To this end, we propose a cross-modal framework VMCML that finds a shared embedding space between video and music representations. To ensure the embedding space can be effectively shared by both representations, we leverage CosFace loss based on margin-based cosine similarity loss. Furthermore, we establish a large-scale dataset called MSVD, in which we provide 390 individual music and the corresponding matched 150,000 videos. We conduct extensive experiments on Youtube-8M and our MSVD datasets. Our quantitative and qualitative results demonstrate the effectiveness of our proposed framework and achieve state-of-the-art video and music matching performance.

cs.CV↗

arXiv2015

Multiple-pulse lasing from an optically induced harmonic confinement in a highly photoexcited microcavity

We report the observation of macroscopic harmonic states in an optically induced confinement in a highly photoexcited semiconductor microcavity at room temperature. The spatially photomodulated refractive index changes result in the visualization of harmonic states in a micrometer-scale optical potential at quantized energies up to 4 meV even in the weak-coupling plasma limit. We characterize the time evolution of the harmonic states directly from the consequent pulse radiation and identify sequential multiple $\sim$10 ps pulse lasing with different emitting angles and frequencies.

cond-mat.mes-hall↗

arXiv2015

Transient dual-energy lasing in a semiconductor microcavity

We demonstrate sequential lasing at two well-separated energies in a highly photoexcited planar microcavity at room temperature. Two spatially overlapped lasing states with distinct polarization properties appear at energies more than 5 meV apart. Under a circularly polarized nonresonant 2 ps pulse excitation, a sub-10-ps transient circularly polarized high-energy (HE) state emerges within 10 ps after the pulse excitation. This HE state is followed by a pulsed state that lasts for 20--50 ps at a low energy (LE) state. The HE state is highly circularly polarized as a result of a spin-preserving stimulated process, while the LE state shows a significantly reduced circular polarization because of a diminishing spin imbalance.

physics.optics↗

arXiv2013

A Room-temperature Spin-polarized Polariton Laser

In the field of spin-controlled semiconductor lasers, massive effort has been focused upon materials with long spin relaxation times (~ns). In contrast, we demonstrate room-temperature spin-polarized ultrafast pulsed lasing in InGaAs quantum wells (~10 ps) embedded within a GaAs microcavity. The microcavity studied here is similar to vertical-cavity surface-emitting lasers (VCSEL) used in optical communication. Unlike a VCSEL, the present polariton laser has nonlinear output and energy shifts owing to the mixing of the free-carrier polarization and cavity light field. At room temperature, we observe features resembling those in exciton-polariton condensates at cryogenic temperatures, including the spontaneous build-up of spatial coherence, macroscopic occupation, and spin polarization. Our results should stimulate activities to exploit spin-orbit interaction and many-body effects for fundamental studies of quantum light-matter fluids and developments of spin-dependent optoelectronic devices.

cond-mat.mes-hall↗