We have investigated the behavior of an optical dipole force trap realized using a mode-locked Nd:YAG laser and have compared performance to a continuous-wave (cw) trap built using the same laser but running in a cw mode. The traps are used to confine ultracold $^{85}\text{R}\text{b}$ atoms which are loaded from a magneto-optical trap (MOT). In most respects, the two traps behave similarly over a wide range of laser parameters provided that the average potential well depth is the same; however, there is a notable difference in the dipole trap loading efficiency dependence on the detuning of the MOT trap laser frequency during the loading stage.We have investigated the behavior of an optical dipole force trap realized using a mode-locked Nd:YAG laser and have compared performance to a continuous-wave (cw) trap built using the same laser but running in a cw mode. The traps are used to confine ultracold $^{85}\text{R}\text{b}$ atoms which are loaded from a magneto-optical trap (MOT). In most respects, the two traps behave similarly over a wide range of laser parameters provided that the average potential well depth is the same; however, there is a notable difference in the dipole trap loading efficiency dependence on the detuning of the MOT trap laser frequency during the loading stage.

Physical Review AApr 2, 20089 citations

Optical Dipole Trap

Galina A. Nemova

SPIE eBooksNov 6, 20190 citations

Feedback and compensation scheme to suppress the thermal effects from a dipole trap beam for the optical fiber microcavity

Yuhao Pan, Li Li, Xiao-Long Zhou +5 more

Cavity quantum electrodynamics (cavity QED) with neutral atoms is a promising platform for quantum information processing and optical fiber Fabry-Pérot microcavity with small mode volume is an important integrant for the large light-matter coupling strength. To transport cold atoms to the microcavity, a high-power optical dipole trap (ODT) beam perpendicular to the cavity axis is commonly used. However, the overlap between the ODT beam and the cavity mirrors causes thermal effects inducing a large cavity shift at the locking wavelength and a differential cavity shift at the probe wavelength which disturbs the cavity resonance. Here, we develop a feedback and compensation scheme to maintain the optical fiber microcavity resonant with the lasers at the locking and probe wavelengths simultaneously. The large cavity shift of 210 times the cavity linewidth, which makes the conventional PID scheme ineffective can be suppressed actively by a PIID feedback scheme with an additional I parameter. Differential cavity shift at the probe wavelength can be understood from the photothermal refraction and thermal expansion effects on the mirror coatings and be passively compensated by changing the frequency of the locking laser. A further normal-mode splitting measurement demonstrates the strong coupling between 85 Rb atoms and cavity mode after the thermal effects are suppressed, which also confirms successful delivery and trapping of atoms into the optical cavity. This scheme can solve the thermal effects of the high-power ODT beam and will be helpful to cavity QED experimental research.Cavity quantum electrodynamics (cavity QED) with neutral atoms is a promising platform for quantum information processing and optical fiber Fabry-Pérot microcavity with small mode volume is an important integrant for the large light-matter coupling strength. To transport cold atoms to the microcavity, a high-power optical dipole trap (ODT) beam perpendicular to the cavity axis is commonly used. However, the overlap between the ODT beam and the cavity mirrors causes thermal effects inducing a large cavity shift at the locking wavelength and a differential cavity shift at the probe wavelength which disturbs the cavity resonance. Here, we develop a feedback and compensation scheme to maintain the optical fiber microcavity resonant with the lasers at the locking and probe wavelengths simultaneously. The large cavity shift of 210 times the cavity linewidth, which makes the conventional PID scheme ineffective can be suppressed actively by a PIID feedback scheme with an additional I parameter. Differential cavity shift at the probe wavelength can be understood from the photothermal refraction and thermal expansion effects on the mirror coatings and be passively compensated by changing the frequency of the locking laser. A further normal-mode splitting measurement demonstrates the strong coupling between 85 Rb atoms and cavity mode after the thermal effects are suppressed, which also confirms successful delivery and trapping of atoms into the optical cavity. This scheme can solve the thermal effects of the high-power ODT beam and will be helpful to cavity QED experimental research.

Optics ExpressNov 18, 20227 citations

Dipole and multipole traps

Sergei V. Ryzhkov, A. Yu. Chirkov

Nov 13, 20180 citations

Atomic dipole traps with Amplified Spontaneous Emission: A proposal

Jean‐François Clément, Véronique Zehnlé, Jean Claude Garreau +1 more

arXiv:1008.0847Optics CommunicationsJul 2, 20101 citation

^{85}\text{R}\text{b}

atoms which are loaded from a magneto-optical trap (MOT). In most respects, the two traps behave similarly over a wide range of laser parameters provided that the average potential well depth is the same; however, there is a notable difference in the dipole trap loading efficiency dependence on the detuning of the MOT trap laser frequency during the loading stage.