Abstract
Cryogenic ultrastable laser cavities push laser stability to new levels due to their lower thermal noise limitation. Vibrational noise is one of the major obstacles to achieve a thermal-noise-limited cryogenic ultrastable laser system. Here, we carefully analyze the vibrational noise contribution to the laser frequency. We measure the vibrational noise from the top of the pulse-tube cryocooler down to the experiment space. Major differences emerge between room and cryogenic temperature operation. We cooled a homemade 6 cm sapphire optical resonator down to 3.4 K. Locking a 1064 nm laser to the resonator, we measure a frequency stability of . The vibration sensitivities change at different excitation frequencies. The vibrational noise analysis of the laser system paves the way for in situ accurate evaluation of vibrational noise for cryogenic systems. This may help in cryostat design and cryogenic precision measurements.
Highlights
Cryogenic-cavity-based ultrastable lasers are one of the most promising options for improving laser stability by reducing the thermal noise limit to 10−17 − 10−18 level [1,2,3,4,5,6,7]
We report in situ vibration measurements under cryogenic temperature, and successfully evaluate the vibrational noise contribution to a cryogenic ultrastable system
The in situ cryogenic vibration measurement right on top of the cryogenic plate clearly demonstrates the vibrational dynamics of the cryostat
Summary
Cryogenic-cavity-based ultrastable lasers are one of the most promising options for improving laser stability by reducing the thermal noise limit to 10−17 − 10−18 level [1,2,3,4,5,6,7]. We use an in situ, high resolution vibration measurement equipment (geophone) under cryogenic temperature to measure the vibration level of the sample holder of a closed-cycle cryostat. Driven by the requirement of the cryogenic ultrastable laser, we carry out vibrational measurements inside a specially designed vibration-reduction pulsetube cryostat by using the properly re-calibrated geophones. We built a cryogenic-cavity-based ultrastable laser system using this specially designed closed-cycle cryostat. The calculated vibrational noise contribution from the measured vibrations and the calibrated vibration sensitivity of the cavity matches well to the measured laser frequency noise. The technique developed paves the way for accurate in situ evaluation of vibrational noise for cryogenic systems, which can be great help for cryostat design and cryogenic precision measurements
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.