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Kerry J. Vahala, California Institute of Technology, USAHigh-Q Physics on-a-Chip for Integrated Optical Time Standards and Frequency SynthesizersCommunication systems leverage the respective strengths of optics and electronics to convey high-bandwidth signals over great distances. These systems were enabled by a revolution in low-optical-loss dielectric fiber, complex integrated circuits as well as devices that link together the optical and electrical worlds. Today, another revolution is leveraging the advantages of optics and electronics in new ways. At its center is the laser frequency comb which provides a coherent link between these two worlds. Significantly, because the link is also bidirectional, performance attributes previously unique to electronics and optics can be shared. The end result has been transformative for time keeping, frequency metrology, precision spectroscopy, microwave-generation, ranging and other technologies. Even more recently, low-optical-loss dielectrics, now in the form of high-Q optical resonators, are enabling the miniaturization of frequency combs. These new `microcombs’ can be integrated with electronics and other optical components to potentially create systems on-a-chip. I will briefly overview the history and elements of frequency combs as well as the physics of the new microcombs. Application of the microcombs for spectroscopy and LIDAR will be discussed. Finally, efforts underway to develop integrated optical clocks and integrated optical frequency synthesizers using the microcomb element are described. |
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Qihuang Gong, Peking University, ChinaLight Manipulating and Detecting at Micro/Nano-ScaleMicro/nano scaile light manipulating can be realized by using nano/mico photonic structures. Using photonic crystal made of the composite materials with large and fast third-order optical nonlinearity, ultrafast and low threshold all-optical switching was demonstrated. Based on tunable Fano resonance or PIT of metallic nanostructures, ultrafast modulations on light transmission were also demonstrated. Moreover, highly sensitive optical sensor were experimentally demonstrated using microcavity and SPP devices. |
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Bahram Jalali, University of California, Los Angeles, USATime Stretch and its Applications in Nonlinear Dynamics, Biomedicine, and Computational ImagingMeasurements of non-repetitive and rare signals that occur on short timescales requires fast real-time measurements that exceed the speed, precision, and record length of digitizers. Time-stretch is an optical hardware accelerator that overcomes the speed limitations of photodetectors and electronic digitizers and enables ultrafast single-shot spectroscopy, imaging and other measurements at refresh rates reaching billions of frames per second with continuous recording spanning trillions of consecutive frames. The technology has opened a new frontier in measurement science and has led to discovery of several new scientific phenomena in nonlinear optics, laser dynamics and diagnostics of relativistic electron beams. It has also created a new class of instruments that have been integrated with artificial intelligence for sensing and biomedical diagnostics. We review the fundamental principles and applications of time stretch including a spin-off technology known as the phase stretch transform, a new computational imaging algorithm that is emerging as the best edge and texture feature extractor for digital images. |
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Susumu Noda, Kyoto University, JapanHigh-Power and High-Beam Quality Photonic-Crystal LasersAchieving high-power and high-beam-quality (namely, high-brightness) semiconductor lasers is important for various applications including direct-laser processing and light detection and ranging (LiDAR) for next-generation smart production and mobility. Although semiconductor lasers with various kinds of resonators have been developed, the usefulness of these lasers has been limited by their low brightness, which is more than one order of magnitude smaller than those of existing gas and fiber/disk lasers. The key challenge in realizing high brightness is to increase the output power while maintaining a good beam quality indicated by a low M2 value. Here, we describe photonic crystal lasers have a potential to enable such a high-brightness operation. Very recently, 10W output power with M2~2 has been successuffly achieved. We believe that these photonic-crystal lasers will allow compact, affordable semiconductor lasers to rival large-scale gas and fiber/disk ones in the future. |