Measuring Starlight with an Ultrafast Laser: Astrocomb Development for the Extremely Large Telescope
Tue, Aug 6, 2024 10:00 AM - 11:00 AM EDT
In this webinar, Yuk Shan Cheng of Heriot-Watt University explores the important role of the Extremely Large Telescope's (ELT) ANDES spectrograph and its need for a high-precision frequency calibrator in order to pursue exciting ventures. She focuses on the development of astrocombs, which are laser frequency comb systems that can provide thousands of stable, atomically referenceable, and evenly spaced calibration lines. Despite their demonstrated success in labs and various telescopes worldwide, integrating astrocombs into modern telescope facilities presents challenges, including aligning their mode spacings with the spectrograph's resolving power and achieving broad spectral coverage, particularly in the UV-blue/green wave band. This presentation covers the approaches to these challenges, recent implementation at the Southern African Large Telescope, and advancements in astrocomb technology at Heriot-Watt University, including the development of the first continuous UV-blue/green astrocomb.
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Industry Innovations in Fiber-Based Frequency Combs: Ultrabroadband Comb with Sub-3-kHz Free-Running Linewidths
Tue, Aug 27, 2024 1:00 PM - 2:00 PM EDT
Femtosecond frequency combs represent unparalleled measurement tools with diverse applications in spectroscopy, metrology, and quantum physics. This talk delves into the critical aspect of maximizing the passive stability of these instruments to unlock their full potential in fundamental science and high-tech industries. By studying systematically, the noise properties of fiber-based frequency combs across varying intracavity dispersion, pump power, and repetition rate parameters, researchers have notably identified distinct minima where the free-running linewidth of the carrier-envelope offset (CEO) frequency fCEO drops below 1 kHz. A comprehensive analysis of individual comb lines across a broad spectral range unveils the specific contributions to phase noise and their interplay. Leveraging these insights, this presentation showcases the development of frequency combs with sharp teeth at designated positions throughout the spectrum from fCEO to 300 THz. These compact systems offer ultrabroadband stability, presenting a new standard for front-end measurement such as integrated quantum clocks experiments based on Strontium atoms. Sponsored by Toptica Photonics.
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