| 研究実績の概要 |
In FY2023, we have achieved the following results.
-We have built a tapered amplifier system to generate high power at Cs-atom magic wavelength (938 nm). We could achieve around 380 mW of fiber-coupled power. Considering the optical losses of the tweezer setup, we expect that we can create around 100 tweezers in free-space and around 50 tweezers on nanofiber.
-We have built an optical setup equipped with acousto-optic deflector (AOD) driven by multiple RF-tones to create a 1-D array of tweezers. The number of tweezer spots and the spacing between them is controlled by the multitone RF-frequencies. The tweezer beams are focused down to a beam waist of 1 micron using an aspheric lens. We could achieve around 30 tweezer spots with good contrast for 4-lambda spacing and 60 tweezer spots with reduced contrast for 2-lambda spacing. It is mainly limited by the field of view of the aspheric lens. The setup is also equipped with EMCCD camera to image single atoms and a galvo mirror to transport the atoms on to the nanofiber.
-We have fabricated high quality photonic crystal cavities on a 300 nm diameter nanofiber. This diameter is crucial for realizing tweezer trap on nanofiber at the magic wavelength. The fabricated cavities have a finesse of more than 200 and the cavity length is smaller than 1 mm. These are crucial parameters to realize an efficient single atom quantum interface.
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