We investigate the influence of the optical Doppler effect on the carrier-envelope frequency (CEF) of a mode-locked pulse train. The laser pulses are Doppler-shifted in frequency during reflection off a periodically moving mirror that is driven by an electro-dynamical exciter inside an f-2f interferometer. Depending on the relative movement of the mirror at the instant of reflection, we experimentally demonstrate a CEF shift of the laser pulses up to ±69 kHz, which is sufficient for the carrier-envelope phase control of laser amplifiers with repetition rates of 10 kHz and beyond. Using piezoelectric thick films, we show that the scheme also appears to be adaptable to the megahertz repetition rates of typical oscillators. As the phase control is exerted extra-cavity, Doppler-induced CEF modulation is virtually free of any side effects of traditional stabilization schemes that typically act on the pump power. Finally, the Doppler scheme may overcome servo loop bandwidth limitations associated with pump power control.
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http://dx.doi.org/10.1364/OL.44.005246 | DOI Listing |
Sci Rep
January 2025
Computational Learning Theory Team, RIKEN-Advanced Intelligence Project, Fukuoka, 819-0395, Japan.
Providing continuous wireless connectivity for high-speed trains (HSTs) is challenging due to their high speeds, making installing numerous ground base stations (BSs) along the HST route an expensive solution, particularly in rural and wilderness areas. This paper proposes using multiple unmanned aerial vehicles (UAVs) to deliver high data rate wireless connectivity for HSTs, taking advantage of their ability to fly, hover, and maneuver at low altitudes. However, autonomously selecting the optimal UAV by the HST is challenging.
View Article and Find Full Text PDFPLoS One
January 2025
School of History Archaeology and Religion, Cardiff University, Cardiff, United Kingdom.
Reconstructing past herd mobility, reproduction, and diet is crucial for understanding animal management practices among the first sedentary farming communities. It can also shed light on how domestic animals were integrated into the existing exchange networks of goods, products, and raw materials, and how they contributed to broader economic and social changes during the Neolithic. Despite the longstanding importance of cattle (Bos taurus) to herders, the role of cattle in the daily, seasonal, and annual cycle of activities of early farming communities remains relatively poorly understood.
View Article and Find Full Text PDFPhys Ther Res
August 2024
Department of Internal Medicine, Sanseikai Kitano Hospital, Japan.
Unlabelled: Patient Background: A 75-year-old man had difficulty moving around at home because of loss of appetite and neglect of medication for several days. He was brought to the emergency room and admitted on the same day with a diagnosis of dehydration and diabetic ketoacidosis. He started physical therapy (PT), had frequent fainting and presyncope due to hypotension, and had difficulty leaving bed.
View Article and Find Full Text PDFJ Oral Biol Craniofac Res
January 2025
Department of Dental Biomedical Sciences, Faculty of Dentistry, Universitas Gadjah Mada, Indonesia.
Background: Retention is an essential element of orthodontic treatment. In the past two decades, numerous biological treatments have been developed to alleviate orthodontic relapse. Pharmacologic bone modulation is a viable approach to mitigate relapse.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Biomedical Engineering and the Institute of Materials Science, University of Connecticut, Storrs, CT, 06269, USA.
Wearable and implantable bioelectronics that can interface for extended periods with highly mobile organs and tissues across a broad pH range would be useful for various applications in basic biomedical research and clinical medicine. The encapsulation of these systems, however, presents a major challenge, as such devices require superior barrier performance against water and ion penetration in challenging pH environments while also maintaining flexibility and stretchability to match the physical properties of the surrounding tissue. Current encapsulation materials are often limited to near-neutral pH conditions, restricting their application range.
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