P. E. G. Baird
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
P. E. G. Baird has a total of 23 co-authors. Here are the top co-authors by number of shared publications:
P. Gill
National Physical Laboratory, Teddington TW11 0LW, United Kingdom
2 shared publications- Charles F. A. Baynham
Department of Physics, Blackett Laboratory, Imperial College London 1 , Prince Consort Road, London SW7 2AZ
1 shared publication - Elizabeth Anne Curtis
National Physical Laboratory
1 shared publication G. Huang
National Physical Laboratory, Teddington TW11 0LW, United Kingdom
1 shared publicationG. P. Barwood
National Physical Laboratory, Teddington TW11 0LW, United Kingdom
1 shared publicationG. Walsh
National Physical Laboratory, Teddington TW11 0LW, United Kingdom
1 shared publication
Latest Publications
- Open AccessMeasurement of differential polarizabilities at a mid-infrared wavelength in $^{171}\mathrm{Yb}^+$An atom exposed to an electric field will experience Stark shifts of its internal energy levels, proportional to their polarizabilities. In optical frequency metrology, the Stark shift due to background black-body radiation (BBR) modifies the frequency of the optical clock transition, and often represents a large contribution to a clock's uncertainty budget. For clocks based on singly-ionized ytterbium, the ion's complex structure makes this shift difficult to calculate theoretically. We present a measurement of the differential polarizabilities of two ultra-narrow optical clock transitions present in $^{171}\mathrm{Yb}^+$, performed by exposing the ion to an oscillating electric field at a wavelength in the region of room temperature BBR spectra. By measuring the frequency shift to the transitions caused by a laser at $\lambda=7.17 \mu m$, we obtain values for scalar and tensor differential polarizabilities with uncertainties at the percent level for both the electric quadrupole and octupole transitions at 436nm and 467nm respectively. These values agree with previously reported experimental measurements and, in the case of the electric quadrupole transition, allow a 5-fold improvement in the determination of the room-temperature BBR shift. However, we note significant concerns over the validity of the uncertainty charactarization presented and draw the reader's attention to the Note on applicability section for a discussion.Open AccessMeasurement of differential polarizabilities at a mid-infrared wavelength in $^{171}\mathrm{Yb}^+$An atom exposed to an electric field will experience Stark shifts of its internal energy levels, proportional to their polarizabilities. In optical frequency metrology, the Stark shift due to background black-body radiation (BBR) modifies the frequency of the optical clock transition, and often represents a large contribution to a clock's uncertainty budget. For clocks based on singly-ionized ytterbium, the ion's complex structure makes this shift difficult to calculate theoretically. We present a measurement of the differential polarizabilities of two ultra-narrow optical clock transitions present in $^{171}\mathrm{Yb}^+$, performed by exposing the ion to an oscillating electric field at a wavelength in the region of room temperature BBR spectra. By measuring the frequency shift to the transitions caused by a laser at $\lambda=7.17 \mu m$, we obtain values for scalar and tensor differential polarizabilities with uncertainties at the percent level for both the electric quadrupole and octupole transitions at 436nm and 467nm respectively. These values agree with previously reported experimental measurements and, in the case of the electric quadrupole transition, allow a 5-fold improvement in the determination of the room-temperature BBR shift. However, we note significant concerns over the validity of the uncertainty charactarization presented and draw the reader's attention to the Note on applicability section for a discussion.
- 1 March 2019
- Published by AIP Publishing in Review of Scientific Instruments
- Vol. 90 (3) , 033105
Compact laser system for a laser-cooled ytterbium ion microwave frequency standard
The development of a transportable microwave frequency standard based on the ground-state transition of 171Yb+ at ∼12.6 GHz requires a compact laser system for cooling the ions, clearing out of long-lived states and also for photoionisation. In this paper, we describe the development of a suitable compact laser system based on a 6U height rack-mounted arrangement with overall dimensions 260 × 194 × 335 mm. Laser outputs at 369 nm (for cooling), 399 nm (photoionisation), 935 nm (repumping), and 760 nm (state clearout) are combined in a fiber arrangement for delivery to our linear ion trap and we demonstrate this system by cooling of 171Yb+ ions. Additionally, we demonstrate that the lasers at 935 nm and 760 nm are close in frequency to water vapor and oxygen absorption lines, respectively; specifically, at 760 nm, we show that one 171Yb+ transition is within the pressure broadened profile of an oxygen line. These molecular transitions form convenient wavelength references for the stabilization of lasers for a 171Yb+ frequency standard.
- 1 March 2019
- Published by AIP Publishing in Review of Scientific Instruments
- Vol. 90 (3) , 033105
Compact laser system for a laser-cooled ytterbium ion microwave frequency standard
The development of a transportable microwave frequency standard based on the ground-state transition of 171Yb+ at ∼12.6 GHz requires a compact laser system for cooling the ions, clearing out of long-lived states and also for photoionisation. In this paper, we describe the development of a suitable compact laser system based on a 6U height rack-mounted arrangement with overall dimensions 260 × 194 × 335 mm. Laser outputs at 369 nm (for cooling), 399 nm (photoionisation), 935 nm (repumping), and 760 nm (state clearout) are combined in a fiber arrangement for delivery to our linear ion trap and we demonstrate this system by cooling of 171Yb+ ions. Additionally, we demonstrate that the lasers at 935 nm and 760 nm are close in frequency to water vapor and oxygen absorption lines, respectively; specifically, at 760 nm, we show that one 171Yb+ transition is within the pressure broadened profile of an oxygen line. These molecular transitions form convenient wavelength references for the stabilization of lasers for a 171Yb+ frequency standard.
- 1 January 2017
- Published by AIP Publishing in Review of Scientific Instruments
- Vol. 88 (1) , 016102
Note: A high-performance, low-cost laser shutter using a piezoelectric cantilever actuator
We report the design and characterization of an optical shutter based on a piezoelectric cantilever. Compared to conventional electro-magnetic shutters, the device has intrinsically low power and is acoustically quiet. The cantilever position is controlled by a high-voltage op-amp circuit for easy tuning of the range of travel, and mechanical slew rate, which enables a factor of 30 reduction in mechanical noise compared to a rapidly switched device. We achieve shuttering rise and fall times of 11 μs, corresponding to mechanical slew rates of 1.3 ms−1, with a timing jitter of less than 1 μs. When used to create optical pulses, we achieve minimum pulse durations of 250 μs. The reliability of the shutter was investigated by operating continuously for one week at 10 Hz switching rate. After this period, neither the shutter delay or actuation speed had changed by a measurable amount.
- 1 January 2017
- Published by AIP Publishing in Review of Scientific Instruments
- Vol. 88 (1) , 016102
Note: A high-performance, low-cost laser shutter using a piezoelectric cantilever actuator
We report the design and characterization of an optical shutter based on a piezoelectric cantilever. Compared to conventional electro-magnetic shutters, the device has intrinsically low power and is acoustically quiet. The cantilever position is controlled by a high-voltage op-amp circuit for easy tuning of the range of travel, and mechanical slew rate, which enables a factor of 30 reduction in mechanical noise compared to a rapidly switched device. We achieve shuttering rise and fall times of 11 μs, corresponding to mechanical slew rates of 1.3 ms−1, with a timing jitter of less than 1 μs. When used to create optical pulses, we achieve minimum pulse durations of 250 μs. The reliability of the shutter was investigated by operating continuously for one week at 10 Hz switching rate. After this period, neither the shutter delay or actuation speed had changed by a measurable amount.
- 14 May 2001
- Published by IOP Publishing in Measurement Science and Technology
- Vol. 12 (6) , 740-743
Two-photon spectroscopy in potassium
The two-photon transitions 4S1/2→6S1/2 and 4S1/2→4D5/2 in atomic potassium have been observed free of the first-order Doppler effect. The rate for the S-D transition, which has been detected for the first time, is two orders of magnitude lower than that for the S-S transition; the observed signal to noise ratios for the S-S and S-D transitions were respectively >200 and ~3. The laser excitation frequencies are located in the near vicinity of 1/6 of the 1S-2S transition interval of hydrogen, deuterium and the hydrogen-like atom, muonium. These potassium transitions may therefore provide a suitable frequency transfer standard for all these systems and a useful link between them.
- 14 May 2001
- Published by IOP Publishing in Measurement Science and Technology
- Vol. 12 (6) , 740-743
Two-photon spectroscopy in potassium
The two-photon transitions 4S1/2→6S1/2 and 4S1/2→4D5/2 in atomic potassium have been observed free of the first-order Doppler effect. The rate for the S-D transition, which has been detected for the first time, is two orders of magnitude lower than that for the S-S transition; the observed signal to noise ratios for the S-S and S-D transitions were respectively >200 and ~3. The laser excitation frequencies are located in the near vicinity of 1/6 of the 1S-2S transition interval of hydrogen, deuterium and the hydrogen-like atom, muonium. These potassium transitions may therefore provide a suitable frequency transfer standard for all these systems and a useful link between them.