Lim Lee

Double resonance optical pumping spectrum and its application for frequency stabilization of a laser diode

We present double resonance optical pumping (DROP) spectra for the 5P3∕2–4D3∕2 transition and the 5P3∕2–4D5∕2 transition of R87b and we use these spectra for frequency stabilization in the 1.5μm region. The spectra, compared to the conventional double resonance spectrum, show a good signal-to-noise ratio and a narrow spectral linewidth for laser frequency stabilization. The different intensities of the hyperfine states were attributed to the different rates of double resonance optical pumping into the other ground state. When we stabilized the frequency of a 1.5μm laser diode to the DROP spectrum, the best frequency stability was 1×10−11 after 100s.

Laser frequency stabilizations using electromagnetically induced transparency

We present two techniques to lock a laser frequency on an atomic transition line by using an electromagnetically induced transparency (EIT) signals, which give optical and electric feedback. We employed these methods to the D2 line of 87Rb atoms. Spectral characteristics of subnatural linewidth EIT allow us to improve frequency stability. By optical feedback of EIT signals, we were able to obtain locking bandwidths of 12 MHz, while frequency stability was 5×10−13 at best after 100 s of integration using a frequency modulation technique.

Transformation of electromagnetically induced transparency into enhanced absorption with a standing-wave coupling field in an Rb vapor cell

We present the transformation of electromagnetically induced transparency (EIT) into narrow enhanced absorption with an on-resonant standing-wave coupling field in the 5S(1/2)-5P(1/2) transition of the Lambda-type system of (87)Rb atoms. When a coupling laser field was changed from a travelling-wave to a standing-wave that was made by adding a counter-propagating L(C) laser, the transmittance spectrum of the L(P) laser transformed the typical EIT into dramatically enhanced absorption, and a Bragg reflection signal was generated by the periodic modulation of atomic absorption. The reflected probe laser corresponding to a Bragg reflection was measured to be approximately 11.5% of the power of the incident probe laser. We analyzed the enhanced absorption signal and Bragg reflection spectrum as a function of the power and frequency detuning of the coupling laser.

A Magneto-optical Trap Below a Dielectric Coated Mirror Surface

A Magneto-Optical Trap (MOT) for

Electromagnetically induced Bragg reflection with a stationary coupling field in a buffer rubidium vapor cell.

^{87}Rb

Combination method of atom trap and time-of-flight mass spectrometer for Ca isotope analysis

atoms near the surface of a dielectric coated mirror at the top of a small

Electromagnetically induced transparency and four wave mixing in coherently coupled Λ system

20{\times}25{\times}40\;mm^3

Double resonance optical pumping effects in electromagnetically induced transparency.

cell has been observed. Two beams of

Reduction of Fringe Noise in a Multi-pass Absorption Cell by Using the Wavelength Modulation Technique

3.3\;mW/cm^2

Passive atomic frequency standard based on coherent population trapping in 87Rb using injection-locked lasers

were used for optical cooling and an anti-Helmholtz magnetic field with a spatial gradient of 9.1 G/cm was used for magnetic trapping. The thickness of the mirror coated on a cover glass was less than