© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Development of an external cavity diode laser for application to spectroscopy and laser cooling and trapping of rubidium

G. N. Botha

Published Mar 1, 2009• 0 citations

Abstract

In the presented study a diode laser was characterised and used for spec- troscopy, measuring the resonance lines of atomic rubidium. The characteristics of diode lasers and external cavity diode lasers (ECDL) for the purposes of ab- sorption spectroscopy were investigated and an experimental setup for tunable diode laser spectroscopy using an ECDL was developed. In external cavity diode lasers, the advantages of low cost, small size and e ciency of a diode laser is combined with tunability and a narrow frequency bandwidth. The ECDL was applied in experimental setups for absorption spectroscopy and saturated ab- sorption spectroscopy. Measurement of the absorption of atomic rubidium's D2 line near 780 nm is discussed. The Doppler broadened, as well as the Doppler free spectrum of the ne and hyper ne structure of the D2 line were measured and is discussed. Finer control of the ECDL's stability and frequency, using a servo circuit, were investigated and tested. An overview is given of laser cool- ing and trapping of neutral rubidium atoms, which is the main application the ECDL were developed for.

Related papers

Low-cost external cavity diode laser for cold atom experiments

Wipawee Temnuch, Sitti Buathong, P Phearivan +1 more

Abstract In this article, the construction of an external cavity diode laser (ECDL) with the wavelength selection and stabilization given by an interference filter in a cateye reflector mirror type instead of using a common grating Littrow configuration is described. We show that our ECDL can be locked for several hours to a given frequency with the broad temperature variation of about 0.2-0.4 °C. A rubidium saturated absorption spectroscopy was used to check our ECDL with the D2 hyperfine transitions. Our low-cost and stabilized ECDL can be used for cold atom experiments as well as in quantum and atom optics applications.

Journal of Physics Conference Series•Jan 1, 2021•1 citation

External Cavity Diode Laser for Ultra-cold Atom Experiments

Benjamin Halkowski

This thesis describes the design, construction and characterization of an external cavity diode laser (ECDL) within the context of AMO research – specifically, ultracold rubidium experiments. The main benefit over other forms of laser light is the ECDL’s low cost and narrow linewidth. Having a more narrow linewidth allows us to affect specific electron states, such as for laser cooling, more precisely than broader alternatives. We find that building such a laser in house is feasible with scan range up to 4 GHz. We also note that attention to external noise, through mechanical vibrations but more importantly through temperature drifts, is necessary to produce an ECDL with a stable optical frequency.

•Jan 1, 2018•0 citations

Rubidium spectroscopy with 778- to 780-nm distributed feedback laser diodes

Anselm J. Deninger, Sebastian Kraft, Frank Lison +1 more

Distributed feedback (DFB) laser chips have recently become available at wavelengths that match the D1 and D2 resonance transitions of alkaline atoms. We investigated the spectral properties, tuning characteristics and modulation behavior of continuous wave, single-mode DFB diodes at 778-780 nm and performed high-resolution spectroscopy of Rubidium vapor. The mode-hop free tuning range of the DFB diodes was as large as 2.4 nm (1186 GHz). The line width of the laser diodes was examined both with a heterodyne beat experiment and with high-resolution Doppler-free two photon spectroscopy, yielding a half width of 2-2.5 MHz. The saturation spectra of the D2-line of 85Rb and 87Rb were recorded with a resolution close to the natural line width. The emission frequency was actively stabilized to Doppler-free transitions with a relative accuracy of better than 4 parts in 109 using commercially available servo devices only. The output power of 80 mW was sufficient to allow for two photon spectroscopy of the 5S-5D-transition of 87Rb. We conclude that the performance of the DFB laser equals that of grating-stabilized external-cavity diode lasers (ECDLs), without the mechanical complexity of the latter systems. The DFB diode is thus well-suited to high-resolution applications in alkaline spectroscopy, including laser cooling and optical manipulation of ultra-cold atoms.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 28, 2005•2 citations

Laser cooling of rubidium atoms in a vapor cell

H. Ludvigsen, A. Äijälä, A. Pietiläinen +2 more

We have constructed a simplified setup for the demonstration of laser cooling and trapping of rubidium atoms. An external-cavity diode laser was swept across the F = 3 → F' = 2, 3, 4 resonances of the D 2 -line of 85 Rb at 780 nm to resolve the saturated absorption features. Subsequently, the transition F = 3 → F' = 4 was used to cool rubidium atoms in a roomtemperature vapor cell. A cold cloud of trapped atoms with a diameter of approximately 1 mm was produced. The lifetime of the trap was measured to be 1 second.

Physica Scripta•Apr 1, 1994•7 citations

A narrow linewidth diode laser system for strontium laser cooling applications

Sarah Nagel

The diode laser system for laser cooling on the 1S 0 → 3P1 intercombination line of strontium discussed in this thesis allows us to cool and trap an atomic strontium sample to 15 muK. Samples in this temperature range are useful for the development of the next generation of atomic frequency standards, cold collision studies, and as a step towards quantum degeneracy. This laser system consists of a Littrow configuration external-cavity diode laser, which is frequency locked to a high finesse cavity. The cavity is subsequently locked to an absorption feature to produce a few mW of tunable, stabilized, single mode power at the target wavelength. We present the design and characterization of this system, including a linewidth measurement of 70 kHz, as well as preliminary results from cooling and trapping.

•Jan 1, 2004•1 citation

Laser Cooling of Neutral Atoms

Strick, Jeffrey E

The theory of cooling neutral atoms to microkelvin temperatures using a magneto optical trap will be presented. The system that is discussed uses a stabilized grating tuned diode laser that is controlled using feedback from a saturation absorption spectrophotometer to produce narrow band continuously tunable IR light for trapping rubidium atoms. A description of the design and construction of each of the components used to create the magneto optical trap will also be discussed. In the final section a description of an exceptionally accurate atomic clock that is used to measure the natural resonance frequency of laser cooled cesium atoms is also presented.

•Jan 1, 2002•0 citations

In the presented study a diode laser was characterised and used for spec- troscopy, measuring the resonance lines of atomic rubidium. The characteristics of diode lasers and external cavity diode lasers (ECDL) for the purposes of ab- sorption spectroscopy were investigated and an experimental setup for tunable diode laser spectroscopy using an ECDL was developed. In external cavity diode lasers, the advantages of low cost, small size and e ciency of a diode laser is combined with tunability and a narrow frequency bandwidth. The ECDL was applied in experimental setups for absorption spectroscopy and saturated ab- sorption spectroscopy. Measurement of the absorption of atomic rubidium's D2 line near 780 nm is discussed. The Doppler broadened, as well as the Doppler free spectrum of the ne and hyper ne structure of the D2 line were measured and is discussed. Finer control of the ECDL's stability and frequency, using a servo circuit, were investigated and tested. An overview is given of laser cool- ing and trapping of neutral rubidium atoms, which is the main application the ECDL were developed for.

Abstract In this article, the construction of an external cavity diode laser (ECDL) with the wavelength selection and stabilization given by an interference filter in a cateye reflector mirror type instead of using a common grating Littrow configuration is described. We show that our ECDL can be locked for several hours to a given frequency with the broad temperature variation of about 0.2-0.4 °C. A rubidium saturated absorption spectroscopy was used to check our ECDL with the D2 hyperfine transitions. Our low-cost and stabilized ECDL can be used for cold atom experiments as well as in quantum and atom optics applications.

This thesis describes the design, construction and characterization of an external cavity diode laser (ECDL) within the context of AMO research – specifically, ultracold rubidium experiments. The main benefit over other forms of laser light is the ECDL’s low cost and narrow linewidth. Having a more narrow linewidth allows us to affect specific electron states, such as for laser cooling, more precisely than broader alternatives. We find that building such a laser in house is feasible with scan range up to 4 GHz. We also note that attention to external noise, through mechanical vibrations but more importantly through temperature drifts, is necessary to produce an ECDL with a stable optical frequency.

Distributed feedback (DFB) laser chips have recently become available at wavelengths that match the D1 and D2 resonance transitions of alkaline atoms. We investigated the spectral properties, tuning characteristics and modulation behavior of continuous wave, single-mode DFB diodes at 778-780 nm and performed high-resolution spectroscopy of Rubidium vapor. The mode-hop free tuning range of the DFB diodes was as large as 2.4 nm (1186 GHz). The line width of the laser diodes was examined both with a heterodyne beat experiment and with high-resolution Doppler-free two photon spectroscopy, yielding a half width of 2-2.5 MHz. The saturation spectra of the D2-line of 85Rb and 87Rb were recorded with a resolution close to the natural line width. The emission frequency was actively stabilized to Doppler-free transitions with a relative accuracy of better than 4 parts in 109 using commercially available servo devices only. The output power of 80 mW was sufficient to allow for two photon spectroscopy of the 5S-5D-transition of 87Rb. We conclude that the performance of the DFB laser equals that of grating-stabilized external-cavity diode lasers (ECDLs), without the mechanical complexity of the latter systems. The DFB diode is thus well-suited to high-resolution applications in alkaline spectroscopy, including laser cooling and optical manipulation of ultra-cold atoms.

We have constructed a simplified setup for the demonstration of laser cooling and trapping of rubidium atoms. An external-cavity diode laser was swept across the F = 3 → F' = 2, 3, 4 resonances of the D 2 -line of 85 Rb at 780 nm to resolve the saturated absorption features. Subsequently, the transition F = 3 → F' = 4 was used to cool rubidium atoms in a roomtemperature vapor cell. A cold cloud of trapped atoms with a diameter of approximately 1 mm was produced. The lifetime of the trap was measured to be 1 second.

The diode laser system for laser cooling on the 1S 0 → 3P1 intercombination line of strontium discussed in this thesis allows us to cool and trap an atomic strontium sample to 15 muK. Samples in this temperature range are useful for the development of the next generation of atomic frequency standards, cold collision studies, and as a step towards quantum degeneracy. This laser system consists of a Littrow configuration external-cavity diode laser, which is frequency locked to a high finesse cavity. The cavity is subsequently locked to an absorption feature to produce a few mW of tunable, stabilized, single mode power at the target wavelength. We present the design and characterization of this system, including a linewidth measurement of 70 kHz, as well as preliminary results from cooling and trapping.

The theory of cooling neutral atoms to microkelvin temperatures using a magneto optical trap will be presented. The system that is discussed uses a stabilized grating tuned diode laser that is controlled using feedback from a saturation absorption spectrophotometer to produce narrow band continuously tunable IR light for trapping rubidium atoms. A description of the design and construction of each of the components used to create the magneto optical trap will also be discussed. In the final section a description of an exceptionally accurate atomic clock that is used to measure the natural resonance frequency of laser cooled cesium atoms is also presented.