A compact ultranarrow high-power laser system for experiments with 578nm Ytterbium clock transition

In this paper we present the realization of a compact, high-power laser system able to excite the Ytterbium clock transition at 578 nm. Starting from an external-cavity laser based on a quantum dot chip at 1156 nm with an intra-cavity electro-optic modulator, we were able to obtain up to 60 mW of visible light at 578 nm via frequency doubling. The laser is locked with a 500 kHz bandwidth to a ultra-low-expansion glass cavity stabilized at its zero coefficient of thermal expansion temperature through an original thermal insulation and correction system. This laser allowed the observation of the clock transition in fermionic $^{173}$Yb with a < 50 Hz linewidth over 5 minutes, limited only by a residual frequency drift of some 0.1 Hz/s

Generation of an ultrastable 578 nm laser for Yb lattice clock

In this paper we described the development and the characterization of a 578 nm laser source to be the clock laser for an Ytterbium Lattice Optical clock. Two independent laser sources have been realized and the characterization of the stability with a beat note technique is presente

Realization and characterization of optical frequency standards

During the Ph.D. Course I worked on the realization and the characterization of an ytterbium optical frequency standard. Since year 2000, it is possible using optical frequency comb to directly and reliably scale a frequency measurement in the optical domain to a measurement in the microwave domain. This possibility allows the realization of high accuracy and high stability optical frequency standards, whose atomic quality factors are several orders of magnitude higher than the best microwave ones. Among others, the alkaline earth atoms are very promising and, once trapped in an optical lattice, are capable of a short term stability approaching 10−15 at 1 s. A ytterbium optical clock is currently being developed in the laboratories of the Optics Division of Istituto Nazionale di Ricerca Metrologica (INRIM) The experiment aims to cool and trap ytterbium atoms in a two stage magneto-optical trap (MOT) (at 399 nm and 556 nm) and to probe them in an optical lattice with a ultrastable laser at 578 nm. This thesis presents the realization of the required laser sources, the stabilization of the clock laser, the development of the cooling and trapping stages and the design of a new experimental setup. The blue and green radiations for the two-stage MOT at 399 nm and 556 nm are obtained by second harmonic generation in non-linear crystals. The yellow clock laser at 578 nm is generated by sum of frequency in non-linear crystal. The clock laser is stabilized with the Pound-Drever-Hall technique on a high-finesse Fabry-Pérot cavity. The temperature stabilization of the cavity is implemented with a novel Active Disturbance Rejection Control scheme. The frequency noise of the laser is characterized with a stability 3 × 10−15 at 1 s. Atoms are trapped in the blue magneto-optical trap at 399 nm and transferred in the green trap at 556 nm. A new experimental setup is designed, studying the vacuum chamber, the MOT coils and the atomic source. I have been guest researcher at National Institute of Standards and Technology (NIST) for six months in 2011. I will describe development of NIST ytterbium optical clocks during my visi

Rotational sensitivity of the "G-Pisa" gyrolaser

G-Pisa is an experiment investigating the possibility to operate a high sensitivity laser gyroscope with area less than $1 \rm m^2$ for improving the performances of the mirrors suspensions of the gravitational wave antenna Virgo. The experimental set-up consists in a He-Ne ring laser with a 4 mirrors square cavity. The laser is pumped by an RF discharge where the RF oscillator includes the laser plasma in order to reach a better stability. The contrast of the Sagnac fringes is typically above 50% and a stable regime has been reached with the laser operating both single mode or multimode. The effect of hydrogen contamination on the laser was also checked. A low-frequency sensitivity, below $1 \rm Hz$, in the range of $10^{-8} \rm {(rad / s)/ \sqrt{Hz}}$ has been measured.Comment: 6 pages, 6 figures, presented at the EFTF-IFCS joint conference 200

Spectral purity transfer with 5 × 10−17 instability at 1 s using a multibranch Er:fiber frequency comb

In this work we describe the spectral purity transfer between a 1156 nm ultrastable laser and a 1542 nm diode laser by means of an Er:fiber multibranch comb. By using both the master laser light at 1156 nm and its second-harmonic at 578 nm, together with the 1542 nm slave laser, we investigate the residual noise between the main comb output, the octave-spanning output, and a wavelength conversion module including non-linear fibers, second-harmonic generation crystal and amplifiers. With an ultimate stability of the system at the level of 5E−17 at 1 s and accuracy of 3E−19, this configuration can sustain spectral transfer at the level required by the contemporary optical clocks with a simple and robust setup

Absolute frequency measurement of the 1S0 - 3P0 transition of 171Yb

We report the absolute frequency measurement of the unperturbed transition 1S0 - 3P0 at 578 nm in 171Yb realized in an optical lattice frequency standard. The absolute frequency is measured 518 295 836 590 863.55(28) Hz relative to a cryogenic caesium fountain with a fractional uncertainty of 5.4x10-16 . This value is in agreement with the ytterbium frequency recommended as a secondary representation of the second in the International System of Units.Comment: This is an author-created, un-copyedited version of an article accepted for publication/published in Metrologia. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/1681-7575/aa4e62. It is published under a CC BY licenc

Realization of an Ultrastable 578-nm Laser for an Yb Lattice Clock

In this paper, we describe the development of an ultrastable laser source at 578 nm, realized using frequency sum generation. This source will be used to excite the clock transition 1S0-3P0 in an ytterbium optical lattice clock experiment. Two independent ultrastable lasers have been realized, and the laser frequency noise and stability have been characterize

Absolute frequency measurement of the 1S0 – 3P0 transition of 171-Yb with a link to International Atomic Time

Dataset of the INRIM Yb clock measured respect to TAI collected between October 2018 to February 2019. YbvsSIm-viaEAL.dat: montly data with columns MJDstart: start date in MJD MJDstop: stop date in MJD MJDmed: mid point date in MJD MJDbaro: baricenter date in MJD Ybduty: Yb clock duty time y0=Yb/HM3: ratio between Yb clock and H Maser 03 u0: statistical uncertainty of y0 uB0: systematic uncertainty of y0 y1=extrap.: extrapolation over HM3 udead1: uncertainty of y1 from dead times udrift1: uncertainty of y1 from HM3 drift HM3drift/d: HM3 drift per day udrift/d: uncertainty of HM3 drift y2=HM3/UTCit: ratio between HM3 and UTC(IT) u2: uncertainty of y2 y3=UTCit/TAI: ratio between UTC(IT) and TAI u3: uncertainty of y3 y4=EALext.: extrapolation over EAL udead4: uncertainty of y4 from dead times udrift4: uncertainty of y4 from EAL drift y5=-d: ratio between TAI and the SI second from Circular T u5: uncertainty of y5 uA5: statistical uncertainty of y5 uB5: systematic uncertainty of y5 y=Yb/SI: final ratio beween the Yb clock and the Si second uA: not used uB: not used u: uncertainty of y YbvsTAId.dat: data every 5 days with columns: MJDstart: start date in MJD MJDstop: stop date in MJD MJDmed: mid point date in MJD MJDbaro: baricenter date in MJD Ybduty: Yb clock duty time y0=Yb/HM3: ratio between Yb clock and H Maser 03 u0: statistical uncertainty of y0 uB0: systematic uncertainty of y0 y1=extrap.: extrapolation over HM3 udead1: uncertainty of y1 from dead times udrift1: uncertainty of y1 from HM3 drift HM3drift/d: HM3 drift per day udrift/d: uncertainty of HM3 drift y2=HM3/UTCit: ratio between HM3 and UTC(IT) u2: uncertainty of y2 y3=UTCit/TAI: ratio between UTC(IT) and TAI u3: uncertainty of y3 y=Yb/TAI: final ratio beween the Yb clock and TAI uA: not used uB: not used u: uncertainty of yWe acknowledge funding from the European Metrology Program for Innovation and Research (EMPIR) project 15SIB03 OC18, from the Horizon 2020 Marie Skłodowska-Curie Research and Innovation Staff Exchange (MSCA-RISE) project Q-SENSE (Grant Agreement Number 691156), from the Italian Space Agency (ASI) funding DTF-Matera, from the EMPIR project 18SIB05 ROCIT. The EMPIR initiative is co-funded by the European Union's Horizon 2020 research and innovation programme and the EMPIR Participating States

Phase noise cancellation in polarisation-maintaining fibre links

The distribution of ultra-narrow linewidth laser radiation is an integral part of many challenging metrological applications. Changes in the optical pathlength induced by environmental disturbances compromise the stability and accuracy of optical fibre networks distributing the laser light and call for active phase noise cancellation. Here we present a laboratory scale optical (at 578 nm) fibre network featuring all polarisation maintaining fibres in a setup with low optical powers available and tracking voltage-controlled oscillators implemented. The stability and accuracy of this system reach performance levels below 1 * 10^(-19) after 10 000 s of averagingComment: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in "Phase noise cancellation in polarisation-maintaining fibre links", Rauf et al., Review of Scientific Instruments, 89, 033103 (2018) and may be found at https://doi.org/10.1063/1.501651