Michele Gozzelino
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Michele Gozzelino has a total of 75 co-authors. Here are the top co-authors by number of shared publications:
- Filippo Levi
Istituto Nazionale di Ricerca Metrologica (INRiM)
9 shared publications - Salvatore Micalizio
INRIM Quantum Metrology and Nanotechnologies Division Istituto Nazionale di Ricerca Metrologica Strada delle Cacce 91 10135 Torino Italy
7 shared publications - Giovanni Antonio Costanzo
Istituto Nazionale di Ricerca Metrologica INRIM, Strada delle Cacce 91, 10135 Torino, Italy
5 shared publications Aldo Godone
Istituto Nazionale di Ricerca Metrologica, INRIM, Torino, Italy
4 shared publications- Cecilia Clivati
Istituto Nazionale di Ricerca Metrologica (INRiM)
4 shared publications Claudio Eligio Calosso
Istituto Nazionale di Ricerca Metrologica, INRIM, Torino, Italy
4 shared publications
Latest Publications
- Open Access
- 1 February 2026
- Published by IOP Publishing in Publications of the Astronomical Society of the Pacific
- Vol. 138 (2) , 024504
A High-frequency Geodetic VLBI Experiment for Optical Clock Comparison
An intercontinental metrological clock comparison between Italy and the Republic of Korea was performed by means of geodetic K -band VLBI observations. The comparison involved the hydrogen masers (H-masers) used at Medicina and Sejong radio telescopes. The same clocks were simultaneously compared by a satellite link and by high-precision optical clocks maintained at the National Metrology Institutes, KRISS in Korea and INRIM in Italy, and delivered to VLBI antennas via optical fiber. The H-masers frequency difference was estimated by extrapolating the clock rate from VLBI data using two geodetic VLBI software. This was subsequently compared with clock differences derived by satellite link and by local optical clocks. Results obtained with different approaches were in agreement at the level of 10 −15 s s −1 . This pilot study demonstrates that standard high-frequency ( K -band) geodetic VLBI campaigns could be a viable approach to conduct intercontinental clock comparisons, now only possible via satellite links. This uncertainty can be reduced thanks to the planned installation of new-generation, broadband, high-frequency receivers on the involved telescopes. K / Q / W -band geodetic observations will allow an improvement of the accuracy of the resulting group delays through broad bandwidth synthesis from 20 to 100 GHz. Furthermore, the Frequency Phase Transfer method will also be explored together with the use of PCAL systems installed at the radio telescopes to improve phase stability and thus allow a better estimation of the station clock parameters.
- 1 February 2026
- Published by IOP Publishing in Publications of the Astronomical Society of the Pacific
- Vol. 138 (2) , 024504
Open AccessA High-frequency Geodetic VLBI Experiment for Optical Clock Comparison
An intercontinental metrological clock comparison between Italy and the Republic of Korea was performed by means of geodetic K -band VLBI observations. The comparison involved the hydrogen masers (H-masers) used at Medicina and Sejong radio telescopes. The same clocks were simultaneously compared by a satellite link and by high-precision optical clocks maintained at the National Metrology Institutes, KRISS in Korea and INRIM in Italy, and delivered to VLBI antennas via optical fiber. The H-masers frequency difference was estimated by extrapolating the clock rate from VLBI data using two geodetic VLBI software. This was subsequently compared with clock differences derived by satellite link and by local optical clocks. Results obtained with different approaches were in agreement at the level of 10 −15 s s −1 . This pilot study demonstrates that standard high-frequency ( K -band) geodetic VLBI campaigns could be a viable approach to conduct intercontinental clock comparisons, now only possible via satellite links. This uncertainty can be reduced thanks to the planned installation of new-generation, broadband, high-frequency receivers on the involved telescopes. K / Q / W -band geodetic observations will allow an improvement of the accuracy of the resulting group delays through broad bandwidth synthesis from 20 to 100 GHz. Furthermore, the Frequency Phase Transfer method will also be explored together with the use of PCAL systems installed at the radio telescopes to improve phase stability and thus allow a better estimation of the station clock parameters.
- Open Access
- 8 May 2025
- Published by Elsevier in Sensors and Actuators A: Physical
- Vol. 391
Activation and characterization of Rb MEMS cells with an automatic system at wafer level
- 8 May 2025
- Published by Elsevier in Sensors and Actuators A: Physical
- Vol. 391
Open AccessActivation and characterization of Rb MEMS cells with an automatic system at wafer level
- Open Access
- 12 September 2024
- Published by American Physical Society (APS) in Physical Review Applied
- Vol. 22 (3) , 034033
Laser-frequency stabilization using light shift in compact atomic clocks
This paper describes the light-shift laser-lock (LSLL) technique, an alternative method intended for laser-based compact atomic clocks. The technique greatly simplifies the laser setup by stabilizing the pumping-laser frequency to the same atoms involved in the clock operation, without the need of an external reference. By alternating two clock sequences, the method estimates and cancels out a controlled amount of induced light shift, acting on the laser frequency. The LSLL technique is compatible with state-of-the-art three-level clocks and was demonstrated with field-programmable-gate-array-based electronics on a pulsed-optically-pumped vapor-cell clock developed at INRIM. The results have shown that the LSLL technique operates robustly, having a capture range of gigahertz without significantly compromising clock stability. In our tests, the clock exhibited a white frequency noise of for averaging times up to 4000 s, reaching a floor below 1× up to 100 000 s. This level of performance meets the requirements of future global navigation satellite systems on-board clocks, adding the benefits of a reduced clock footprint, as well as increased reliability and robustness.- 12 September 2024
- Published by American Physical Society (APS) in Physical Review Applied
- Vol. 22 (3) , 034033
Open AccessLaser-frequency stabilization using light shift in compact atomic clocks
This paper describes the light-shift laser-lock (LSLL) technique, an alternative method intended for laser-based compact atomic clocks. The technique greatly simplifies the laser setup by stabilizing the pumping-laser frequency to the same atoms involved in the clock operation, without the need of an external reference. By alternating two clock sequences, the method estimates and cancels out a controlled amount of induced light shift, acting on the laser frequency. The LSLL technique is compatible with state-of-the-art three-level clocks and was demonstrated with field-programmable-gate-array-based electronics on a pulsed-optically-pumped vapor-cell clock developed at INRIM. The results have shown that the LSLL technique operates robustly, having a capture range of gigahertz without significantly compromising clock stability. In our tests, the clock exhibited a white frequency noise of for averaging times up to 4000 s, reaching a floor below 1× up to 100 000 s. This level of performance meets the requirements of future global navigation satellite systems on-board clocks, adding the benefits of a reduced clock footprint, as well as increased reliability and robustness. - Open Access
Laser Frequency Stabilization Using Light Shift in Compact Atomic Clocks
This paper describes the Light-Shift Laser-Lock (LSLL) technique, a novel method intended for compact atomic clocks that greatly simplifies the laser setup by stabilizing the pumping-laser frequency to the atoms involved in the clock, without the need of an external reference. By alternating two clock sequences with different light shifts, the method estimates and cancels out a controlled amount of induced light shift, acting on the laser frequency. The LSLL technique is compatible with state-of-the-art 3-level clocks and was demonstrated with FPGA-based electronics on a pulsed-optically-pumped (POP) vapor-cell clock developed at INRIM. The results have shown that the LSLL technique operates robustly, having a capture range of gigahertz without significantly compromising clock stability. In our tests, the clock exhibited a white frequency noise of $3.2 \times 10^{-13}$ $τ^{-1/2}$ for averaging time up to 4000 s, reaching a floor below $1 \times 10^{-14}$ up to 100 000 s. These performance levels meet the requirements of future Global Navigation Satellite Systems (GNSS) on-board clocks, and offer the added benefits of a reduced clock footprint, as well as increased reliability and robustness.Open AccessLaser Frequency Stabilization Using Light Shift in Compact Atomic Clocks
This paper describes the Light-Shift Laser-Lock (LSLL) technique, a novel method intended for compact atomic clocks that greatly simplifies the laser setup by stabilizing the pumping-laser frequency to the atoms involved in the clock, without the need of an external reference. By alternating two clock sequences with different light shifts, the method estimates and cancels out a controlled amount of induced light shift, acting on the laser frequency. The LSLL technique is compatible with state-of-the-art 3-level clocks and was demonstrated with FPGA-based electronics on a pulsed-optically-pumped (POP) vapor-cell clock developed at INRIM. The results have shown that the LSLL technique operates robustly, having a capture range of gigahertz without significantly compromising clock stability. In our tests, the clock exhibited a white frequency noise of $3.2 \times 10^{-13}$ $τ^{-1/2}$ for averaging time up to 4000 s, reaching a floor below $1 \times 10^{-14}$ up to 100 000 s. These performance levels meet the requirements of future Global Navigation Satellite Systems (GNSS) on-board clocks, and offer the added benefits of a reduced clock footprint, as well as increased reliability and robustness. - 15 May 2023
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 1-2
IT-Yb1 Optical Lattice Clock: Absolute Frequency Measurement at the Cs Fountain Uncertainty Level
SummaryWe report the result of the new absolute frequency measurement of 171 Yb performed at INRIM. The frequency of our optical lattice clock IT-Yb1 is measured against the local cryogenic Cs fountain IT-CsF2 during a campaign that lasted 14 months. The frequency measurements were performed with two different techniques, i.e. using a hydrogen maser as a transfer oscillator or by synthesizing a low-noise microwave for the Cs interrogation from the Yb ultrastable laser with an optical frequency comb. The frequency of the Yb unperturbed clock transition $^1{S_0}{ \to ^3}{P_0}$ is 518 295 836 590 863.44(14) Hz, with a total fractional uncertainty of 2.7 × 10 –16 , limited by the uncertainty of IT-CsF2. This is the absolute frequency measurement of a Yb clock against a Cs fountain with the lowest uncertainty. The result agrees with the Yb frequency value recommended by the Consultative Committee for Time and Frequency (CCTF). Moreover, the Yb data acquired during this campaign have been submitted to the Bureau of Weights and Measures (BIPM) to contribute to the calibration of the International Atomic Time (TAI). This work confirms the reliability of Yb as a secondary representation of the second.- 15 May 2023
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 1-2
IT-Yb1 Optical Lattice Clock: Absolute Frequency Measurement at the Cs Fountain Uncertainty Level
SummaryWe report the result of the new absolute frequency measurement of 171 Yb performed at INRIM. The frequency of our optical lattice clock IT-Yb1 is measured against the local cryogenic Cs fountain IT-CsF2 during a campaign that lasted 14 months. The frequency measurements were performed with two different techniques, i.e. using a hydrogen maser as a transfer oscillator or by synthesizing a low-noise microwave for the Cs interrogation from the Yb ultrastable laser with an optical frequency comb. The frequency of the Yb unperturbed clock transition $^1{S_0}{ \to ^3}{P_0}$ is 518 295 836 590 863.44(14) Hz, with a total fractional uncertainty of 2.7 × 10 –16 , limited by the uncertainty of IT-CsF2. This is the absolute frequency measurement of a Yb clock against a Cs fountain with the lowest uncertainty. The result agrees with the Yb frequency value recommended by the Consultative Committee for Time and Frequency (CCTF). Moreover, the Yb data acquired during this campaign have been submitted to the Bureau of Weights and Measures (BIPM) to contribute to the calibration of the International Atomic Time (TAI). This work confirms the reliability of Yb as a secondary representation of the second.- Open Access
- 3 May 2023
- Published by IOP Publishing in Metrologia
- Vol. 60 (3) , 035002
Absolute frequency measurement of a Yb optical clock at the limit of the Cs fountain
We present the new absolute frequency measurement of ytterbium (171Yb) obtained at INRiM with the optical lattice clock IT-Yb1 against the cryogenic caesium (133Cs) fountain IT-CsF2, evaluated through a measurement campaign that lasted 14 months. Measurements are performed by either using a hydrogen maser as a transfer oscillator or by synthesizing a low-noise microwave for Cs interrogation using an optical frequency comb. The frequency of the 171Yb unperturbed clock transition 1 S 0 → 3 P0 results to be 518 295 836 590 863.44(14) Hz, with a total fractional uncertainty of 2.7 × 10 − 16 that is limited by the uncertainty of IT-CsF2. Our measurement is in agreement with the Yb frequency recommended by the Consultative Committee for Time and Frequency. This result confirms the reliability of Yb as a secondary representation of the second and is relevant to the process of redefining the second in the International System of Units on an optical transition.
- 3 May 2023
- Published by IOP Publishing in Metrologia
- Vol. 60 (3) , 035002
Open AccessAbsolute frequency measurement of a Yb optical clock at the limit of the Cs fountain
We present the new absolute frequency measurement of ytterbium (171Yb) obtained at INRiM with the optical lattice clock IT-Yb1 against the cryogenic caesium (133Cs) fountain IT-CsF2, evaluated through a measurement campaign that lasted 14 months. Measurements are performed by either using a hydrogen maser as a transfer oscillator or by synthesizing a low-noise microwave for Cs interrogation using an optical frequency comb. The frequency of the 171Yb unperturbed clock transition 1 S 0 → 3 P0 results to be 518 295 836 590 863.44(14) Hz, with a total fractional uncertainty of 2.7 × 10 − 16 that is limited by the uncertainty of IT-CsF2. Our measurement is in agreement with the Yb frequency recommended by the Consultative Committee for Time and Frequency. This result confirms the reliability of Yb as a secondary representation of the second and is relevant to the process of redefining the second in the International System of Units on an optical transition.
- 1 January 2023
- Published by Optica Publishing Group
- p. JTu2A.48
Laser-pumped Rb clock for the space sector
We report the recent characterization of a Rb microwave clock based on pulsed laser pumping and detection. The laser pulses were generated by means of a mixed analog-digital controller that stabilizes the pulses amplitude and reduces the laser intensity noise (RIN). The physics package was developed by Leonardo S.p.A. using space-graded components, weighting less than 4 kg and occupying only a 4-liters volume. State-of-the-art short- and mid-term stability is obtained with this system, reaching σy(40000s) = 5 × 10-16 for a 200000 s run.
- 1 January 2023
- Published by Optica Publishing Group
- p. JTu2A.48
Laser-pumped Rb clock for the space sector
We report the recent characterization of a Rb microwave clock based on pulsed laser pumping and detection. The laser pulses were generated by means of a mixed analog-digital controller that stabilizes the pulses amplitude and reduces the laser intensity noise (RIN). The physics package was developed by Leonardo S.p.A. using space-graded components, weighting less than 4 kg and occupying only a 4-liters volume. State-of-the-art short- and mid-term stability is obtained with this system, reaching σy(40000s) = 5 × 10-16 for a 200000 s run.
- Open Access
- 3 November 2022
- Published by American Physical Society (APS) in Physical Review Applied
- Vol. 18 (5) , 054009
Coherent Optical-Fiber Link Across Italy and France
The dissemination of atomic clocks with fiber-based techniques finds application in the fields of metrology, fundamental physics, navigation, and spectroscopy but is a challenge in terms of reliability, maintenance, and performance. Here, we describe the realization of a 1023-km-long fiber link between the metrological institutes of Italy and France that shares the infrastructure with the Internet traffic and exploits segmentation in shorter, cascaded spans to fight optical losses exceeding 280 dB. With four months of quasicontinuous operation of this link, we compared the , , and atomic clocks at our laboratories, highlighting the potential of this tool to assess the clock uncertainty budgets, characterize advanced satellite techniques, and develop optical timescales. The integration of the metrological, fiber-based infrastructures in the two countries, connecting photonics and spectroscopy laboratories as well as telescope facilities, provides the research community with a physical layer over which applications can be built on.- 3 November 2022
- Published by American Physical Society (APS) in Physical Review Applied
- Vol. 18 (5) , 054009
Open AccessCoherent Optical-Fiber Link Across Italy and France
The dissemination of atomic clocks with fiber-based techniques finds application in the fields of metrology, fundamental physics, navigation, and spectroscopy but is a challenge in terms of reliability, maintenance, and performance. Here, we describe the realization of a 1023-km-long fiber link between the metrological institutes of Italy and France that shares the infrastructure with the Internet traffic and exploits segmentation in shorter, cascaded spans to fight optical losses exceeding 280 dB. With four months of quasicontinuous operation of this link, we compared the , , and atomic clocks at our laboratories, highlighting the potential of this tool to assess the clock uncertainty budgets, characterize advanced satellite techniques, and develop optical timescales. The integration of the metrological, fiber-based infrastructures in the two countries, connecting photonics and spectroscopy laboratories as well as telescope facilities, provides the research community with a physical layer over which applications can be built on. - 25 October 2022
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Instrumentation and Measurement
- Vol. 71 (00189456) , 1-8
Frequency Noise Characterization of Diode Lasers for Vapor-Cell Clock Applications
The knowledge of the frequency noise spectrum of a diode laser is of interest in several high-resolution experiments. Specifically, in laser-pumped vapor cell clocks, it is well established that the laser frequency noise plays a role in affecting clock performances. It is then relevant to characterize the frequency noise of a diode laser since such measurements are rarely found in the literature and hardly ever provided by vendors. In this paper, we describe a technique based on a frequency-to-voltage converter that transforms the laser frequency fluctuations into voltage fluctuations. In this way, it is possible to characterize the laser frequency noise power spectral density in a wide range of Fourier frequencies, as required in cell clock applications.
- 25 October 2022
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Instrumentation and Measurement
- Vol. 71 (00189456) , 1-8
Frequency Noise Characterization of Diode Lasers for Vapor-Cell Clock Applications
The knowledge of the frequency noise spectrum of a diode laser is of interest in several high-resolution experiments. Specifically, in laser-pumped vapor cell clocks, it is well established that the laser frequency noise plays a role in affecting clock performances. It is then relevant to characterize the frequency noise of a diode laser since such measurements are rarely found in the literature and hardly ever provided by vendors. In this paper, we describe a technique based on a frequency-to-voltage converter that transforms the laser frequency fluctuations into voltage fluctuations. In this way, it is possible to characterize the laser frequency noise power spectral density in a wide range of Fourier frequencies, as required in cell clock applications.
- Open Access
Frequency noise characterization of diode lasers for vapor cell clocks applications
The knowledge of the frequency noise spectrum of a diode laser is of interest in several high resolution experiments. Specifically, in laser-pumped vapor cell clocks, it is well established that the laser frequency noise plays a role in affecting the clock performances. It is then important to characterize the frequency noise of a diode laser, especially since such measurements are rarely found in the literature and hardly ever provided by vendors. In this paper, we describe a technique based on a frequency-to-voltage converter that transforms the laser frequency fluctuations into voltage fluctuations. In this way, it is possible to characterize the laser frequency noise power spectral density in a wide range of Fourier frequencies, as required in cell clock applications.
Open AccessFrequency noise characterization of diode lasers for vapor cell clocks applications
The knowledge of the frequency noise spectrum of a diode laser is of interest in several high resolution experiments. Specifically, in laser-pumped vapor cell clocks, it is well established that the laser frequency noise plays a role in affecting the clock performances. It is then important to characterize the frequency noise of a diode laser, especially since such measurements are rarely found in the literature and hardly ever provided by vendors. In this paper, we describe a technique based on a frequency-to-voltage converter that transforms the laser frequency fluctuations into voltage fluctuations. In this way, it is possible to characterize the laser frequency noise power spectral density in a wide range of Fourier frequencies, as required in cell clock applications.