Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

URSI Regional Conference on Radio Science (URSI-RCRS)

Phase Stabilized Diode Laser Frequencies for Raman Beam Generation

- Anju, Aishik Acharya

Published Jan 1, 2024• 0 citations
Publisher

Abstract

The advancement of cold atom gravimeters (CAG) is based on the precise control and stabilization of lasers used for the atom interferometry.The 5S → 5P transition in rubidium (Rb) at 780.241 nm is crucial for such quantum technology applications.In this study, the hyperfine structure of 5 2 S1/2 → 5 2 P3/2, D2 transition line of 87 Rb atoms obtained through saturation absorption spectroscopy, are used as a reference for the frequency stabilization of an external cavity diode laser (ECDL) operating at 780 nm.The ECDL is locked to the hyperfine saturated absorption peak of 87 Rb (F = 2 → 3').This laser beam is combined with another 780 nm ECDL laser to obtain the beat frequency spectrum, generating a beat note signal of ~ 6.8 GHz, which is needed for phase stabilization between lasers.These are critical for the Raman beam generation in the CAG, as the 87 Rb atoms ground hyperfine states (F = 1 and F = 2) have separation of ~ 6.834 GHz, and two Raman beams with an 6.8 GHz offset can drive transitions between these hyperfine states of 87 Rb to realize the CAG interferometry scheme.

DOI
10.46620/ursi_rsrc24/0996uvl1515

Related papers

Phase locking technology for Raman laser system based on 1560 nm external cavity lasers

Kainan Wang, Bing Cheng, Yin Zhou +8 more

The technology of generating Raman laser is not only an important research content in the field of quantum precision measurement, but also a core technology of quantum inertial sensors such as cold atom gravimeter, gyroscope. For 87Rb atoms, two 780-nm lasers with a frequency difference of 6.834 GHz and a stable phase are needed to generate Raman light. Raman lasers can be generated by optical phase-locked loops of two 780-nm narrow linewidth external cavity tunable semiconductor lasers (ECDL). But the system thus developed is complicated in structure and very poor in environmental adaptability. The other method to generate Raman laser is based on intracavity 1560-nm laser with frequency doubling and electro-optic modulation technology. This system is simple in structure and strong in environmental adaptability, but it will introduce sideband effects and cannot achieve phase lock due to the limit by the linewidth and feedback bandwidth performance of the laser. In view of this, based on two new 1560-nm external cavity lasers and a home-made phase-locked circuit, in this paper the phase lock of the laser is achieved, and a Raman laser with low phase noise is obtained. The phase noise of beat note signal is as low as –95 dBc/Hz at the Fourier frequency in a range from 1 kHz to 10 kHz. A comparison of this system with the phase-locked performance of the 780-nm dual laser and the hybrid dual laser shows that this scheme has a slight advantage. In addition, the effect of the phase-locking performance on the phase noise of the cold atom interferometer through the method of piecewise integration is analyzed in this work. The experimental results given in this work provide a scheme for developing a miniaturized Raman optical system suitable for external fields.

Acta Physica Sinica•Jan 1, 2021•1 citation

Raman coupling in atomic Bose-Einstein condensed with phase-locked laser system

Zengming Meng, Lianghui Huang, Peng Peng +4 more

We present a simple, versatile and reliable phase-locked laser system. The system consists of an external cavity diode laser, Ti: Sapphire laser, fast detector, phase frequency detector (PFD) and loop filters. The beat signal of the laser is detected with a detector. From the PFD, we can obtain an error signal. The loop filter converts the output of the PFD into a control voltage and thus drives piezoelectric ceramic transducer (PZT) and current of diode laser. After locking, the bandwidth of the beat signal is reduced form MHz to Hz. So the line-width of the diode laser is almost close to that of Ti: Sapphire laser. The locking range is from sub-MHz to 10 GHz. So it is used for the ground hyperfine state transition of 87Rb. Through the use of the phase-locked loop system, we can drive the transition of 87Rb atoms between two ground hyperfine states F=2 and 1. The system is used to demonstrate Raman transition between two states through changing the detuning of the beat signal. From this, we can obtain Rabi frequency = 10 kHz. So, this system can be used to induce an effective vector gauge potential for 87Rb Bose-Einstein condensed and realize the spin-orbit coupling.

Acta Physica Sinica•Jan 1, 2015•2 citations

A tunable dual-frequency rubidium Faraday laser

Xiaomin Qin, Zijie Liu, Zhiyang Wang +7 more

Dual-frequency (DF) lasers with specific frequency intervals have crucial applications in geometric measurement, optical microwave generation, quantum precision measurement, etc. Here, we report a 780 nm DF rubidium Faraday laser, with two modes’ frequencies corresponding to the 85 Rb and 87 Rb D 2 transitions. The microwave signal generated from the two laser modes’ beat has a linewidth of 671 Hz and is tunable from 4.7–4.95 GHz to 5.94–6.7 GHz by adjusting the diode current. Moreover, we use modulation transfer spectroscopy to lock one of the laser modes to the 87 Rb hyperfine transition, and the frequency stability improves nearly an order of magnitude. The noise characteristics are also measured, where the phase noise is suppressed over 25 dB at 100 Hz offset compared to the microwave signal generated by two single-mode lasers’ heterodyne beat. This 780 nm DF rubidium Faraday laser has two coherent modes with frequencies related to Rb transitions, which provides a promising and convenient method for compact atomic physics applications, such as coherent population trapping clocks, atom gravimeters, and so on.

Optics & Laser Technology•Jun 26, 2025•4 citations

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

Note: Generation of Raman laser beams based on a sideband injection-locking technique using a fiber electro-optical modulator

Hongbo Xue, Yanying Feng, X. J. Wang +2 more

Two phase-coherent Raman laser beams with a frequency offset of 6.835 GHz were generated by sideband injection-locking technique. A master diode laser was phase-modulated at 6.835 GHz by a fiber electro-optic modulator. A slave diode was injection-locked to the -1 sideband of the phase-modulated beam, and another diode was locked to the master laser carrier. This method produced stable and spatially separated Raman lasers with a large frequency shift range (>180 MHz). The relative linewidth of these two beams was ∼1 Hz, and the unwanted carrier mode was suppressed down to -24 dB. Stimulated Raman transitions and Ramsey fringes were driven by Raman lasers in a cold atomic beam.

Review of Scientific Instruments•Apr 1, 2013•12 citations

Laser frequency stabilization and shifting by using modulation transfer spectroscopy

Bing Cheng, Zhaoying Wang, Bin Wu +4 more

The stabilizing and shifting of laser frequency are very important for the interaction between the laser and atoms. The modulation transfer spectroscopy for the 87 Rb atom with D2 line transition F = 2 → F′ = 3 is used for stabilizing and shifting the frequency of the external cavity grating feedback diode laser. The resonant phase modulator with electro—optical effect is used to generate frequency sideband to lock the laser frequency. In the locking scheme, circularly polarized pump- and probe-beams are used. By optimizing the temperature of the vapor, the pump- and probe-beam intensity, the laser linewidth of 280 kHz is obtained. Furthermore, the magnetic field generated by a solenoid is added into the system. Therefore the system can achieve the frequency locking at any point in a range of hundreds of megahertz frequency shifting with very low power loss.

Chinese Physics B•Oct 1, 2014•25 citations
The advancement of cold atom gravimeters (CAG) is based on the precise control and stabilization of lasers used for the atom interferometry.The 5S → 5P transition in rubidium (Rb) at 780.241 nm is crucial for such quantum technology applications.In this study, the hyperfine structure of 5 2 S1/2 → 5 2 P3/2, D2 transition line of 87 Rb atoms obtained through saturation absorption spectroscopy, are used as a reference for the frequency stabilization of an external cavity diode laser (ECDL) operating at 780 nm.The ECDL is locked to the hyperfine saturated absorption peak of 87 Rb (F = 2 → 3').This laser beam is combined with another 780 nm ECDL laser to obtain the beat frequency spectrum, generating a beat note signal of ~ 6.8 GHz, which is needed for phase stabilization between lasers.These are critical for the Raman beam generation in the CAG, as the 87 Rb atoms ground hyperfine states (F = 1 and F = 2) have separation of ~ 6.834 GHz, and two Raman beams with an 6.8 GHz offset can drive transitions between these hyperfine states of 87 Rb to realize the CAG interferometry scheme.
The technology of generating Raman laser is not only an important research content in the field of quantum precision measurement, but also a core technology of quantum inertial sensors such as cold atom gravimeter, gyroscope. For 87Rb atoms, two 780-nm lasers with a frequency difference of 6.834 GHz and a stable phase are needed to generate Raman light. Raman lasers can be generated by optical phase-locked loops of two 780-nm narrow linewidth external cavity tunable semiconductor lasers (ECDL). But the system thus developed is complicated in structure and very poor in environmental adaptability. The other method to generate Raman laser is based on intracavity 1560-nm laser with frequency doubling and electro-optic modulation technology. This system is simple in structure and strong in environmental adaptability, but it will introduce sideband effects and cannot achieve phase lock due to the limit by the linewidth and feedback bandwidth performance of the laser. In view of this, based on two new 1560-nm external cavity lasers and a home-made phase-locked circuit, in this paper the phase lock of the laser is achieved, and a Raman laser with low phase noise is obtained. The phase noise of beat note signal is as low as –95 dBc/Hz at the Fourier frequency in a range from 1 kHz to 10 kHz. A comparison of this system with the phase-locked performance of the 780-nm dual laser and the hybrid dual laser shows that this scheme has a slight advantage. In addition, the effect of the phase-locking performance on the phase noise of the cold atom interferometer through the method of piecewise integration is analyzed in this work. The experimental results given in this work provide a scheme for developing a miniaturized Raman optical system suitable for external fields.
We present a simple, versatile and reliable phase-locked laser system. The system consists of an external cavity diode laser, Ti: Sapphire laser, fast detector, phase frequency detector (PFD) and loop filters. The beat signal of the laser is detected with a detector. From the PFD, we can obtain an error signal. The loop filter converts the output of the PFD into a control voltage and thus drives piezoelectric ceramic transducer (PZT) and current of diode laser. After locking, the bandwidth of the beat signal is reduced form MHz to Hz. So the line-width of the diode laser is almost close to that of Ti: Sapphire laser. The locking range is from sub-MHz to 10 GHz. So it is used for the ground hyperfine state transition of 87Rb. Through the use of the phase-locked loop system, we can drive the transition of 87Rb atoms between two ground hyperfine states F=2 and 1. The system is used to demonstrate Raman transition between two states through changing the detuning of the beat signal. From this, we can obtain Rabi frequency = 10 kHz. So, this system can be used to induce an effective vector gauge potential for 87Rb Bose-Einstein condensed and realize the spin-orbit coupling.
Dual-frequency (DF) lasers with specific frequency intervals have crucial applications in geometric measurement, optical microwave generation, quantum precision measurement, etc. Here, we report a 780 nm DF rubidium Faraday laser, with two modes’ frequencies corresponding to the 85 Rb and 87 Rb D 2 transitions. The microwave signal generated from the two laser modes’ beat has a linewidth of 671 Hz and is tunable from 4.7–4.95 GHz to 5.94–6.7 GHz by adjusting the diode current. Moreover, we use modulation transfer spectroscopy to lock one of the laser modes to the 87 Rb hyperfine transition, and the frequency stability improves nearly an order of magnitude. The noise characteristics are also measured, where the phase noise is suppressed over 25 dB at 100 Hz offset compared to the microwave signal generated by two single-mode lasers’ heterodyne beat. This 780 nm DF rubidium Faraday laser has two coherent modes with frequencies related to Rb transitions, which provides a promising and convenient method for compact atomic physics applications, such as coherent population trapping clocks, atom gravimeters, and so on.
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.
Two phase-coherent Raman laser beams with a frequency offset of 6.835 GHz were generated by sideband injection-locking technique. A master diode laser was phase-modulated at 6.835 GHz by a fiber electro-optic modulator. A slave diode was injection-locked to the -1 sideband of the phase-modulated beam, and another diode was locked to the master laser carrier. This method produced stable and spatially separated Raman lasers with a large frequency shift range (>180 MHz). The relative linewidth of these two beams was ∼1 Hz, and the unwanted carrier mode was suppressed down to -24 dB. Stimulated Raman transitions and Ramsey fringes were driven by Raman lasers in a cold atomic beam.
The stabilizing and shifting of laser frequency are very important for the interaction between the laser and atoms. The modulation transfer spectroscopy for the 87 Rb atom with D2 line transition F = 2 → F′ = 3 is used for stabilizing and shifting the frequency of the external cavity grating feedback diode laser. The resonant phase modulator with electro—optical effect is used to generate frequency sideband to lock the laser frequency. In the locking scheme, circularly polarized pump- and probe-beams are used. By optimizing the temperature of the vapor, the pump- and probe-beam intensity, the laser linewidth of 280 kHz is obtained. Furthermore, the magnetic field generated by a solenoid is added into the system. Therefore the system can achieve the frequency locking at any point in a range of hundreds of megahertz frequency shifting with very low power loss.