Related papers: Doppler-free two-photon resonances for atom detect…
We present an experimental scheme that produces Doppler-free spectra of the $5s \to 6p $ second resonance transition in atomic rubidium. The experiment uses the saturation of the cascade fluorescence that occurs when thermal rubidium atoms…
Three-photon laser excitation of Rydberg states by three different laser beams can be arranged in a star-like geometry that simultaneously eliminates the recoil effect and Doppler broadening. Our analytical and numerical calculations for a…
We report observation of the $\rm 5S_{1/2} \rightarrow 5D_{5/2}$ two-photon transition in Rb vapor at 778 nm, using an external cavity diode laser system and a heated vapor cell. The spectra in the two isotopes show well-resolved hyperfine…
Population inversion on the 5D-6P transition in Rb atoms produced by cw excitation at different wavelengths has been analysed by comparing the generated mid-IR radiation at 5.23 um originated from amplified spontaneous emission and…
The two-photon transition $5S-5P-5D$ in rubidium vapor is investigated by detecting the fluorescence from the $6P_{3/2}$ state when the atomic system is excited by the combined action of a cw diode laser and a train of ultrashort pulses.…
Vapour cell spectroscopy is an essential technique in many fields; in particular, nearly all atom and ion trapping experiments rely on simultaneous spectroscopy of two atomic transitions, traditionally employing separate apparatus for each…
A phase-stabilized femtosecond laser comb is directly used for high-resolution spectroscopy and absolute optical frequency measurements of one- and two-photon transitions in laser-cooled \rb atoms. Absolute atomic transition frequencies,…
In this paper, we describe two complementary non-linear spectroscopy methods which both allow to achieve Doppler-free spectra of atomic gases. First, saturated absorption spectroscopy is used to investigate the structure of the $5{\rm…
Rubidium two-photon frequency standards are emerging as powerful contenders for compact, durable devices with exceptional stability. The field has focused on single-color excitation to date. Here we demonstrate the key advantages of a…
We study the two-photon laser excitation to the 5D$_{5/2}$ energy level of $^{85}$Rb atoms contained in the interstices of a porous material made from sintered ground glass with typical pore dimensions in the 10 - 100 $\mu$m range. The…
The features of Doppler-free resonances detected by probing the $^{133}$Cs atom $6S_{1/2}-7P_{3/2}$ transition at 456 nm in a nanometric-thick vapor layer are investigated. The matrix element of this transition is about 11 times smaller…
We demonstrate the use of the ultrafast spatial coherent-control method to resolve the fine-structure two-photon transitions of atomic rubidium. Counter-propagating ultrafast optical pulses with spectral phase and amplitude programmed with…
We present an experimental and theoretical investigation of two-photon direct frequency-comb spectroscopy performed through velocity-selective excitation. In particular, we explore the effect of repetition rate on the…
An experimental realization of high-precision direct frequency comb spectroscopy using counter-propagating femtosecond pulses on two-photon atomic transitions is presented. Doppler broadened background signal, hampering precision…
We report on the combined action of a cw diode laser and a train of ultrashort pulses when each of them drives one step of the 5S-5P-5D two-photon transition in rubidium vapor. The fluorescence from the 6P_{3/2} state is detected for a…
We demonstrate a two-photon transition of rubidium (Rb) atoms from the ground state (5$S_{1/2}$) to the excited state (4$D_{5/2}$), using a home-built ytterbium (Yb)-doped fiber amplifier at 1033 nm. This is the first demonstration of an…
The feasibility of sub-Doppler broadband multi-heterodyne spectroscopy with two laser frequency combs is demonstrated with two-photon excitation spectra of the 5S-5D transitions of rubidium vapor.
We present the first evidence of excitation of the $5p_{3/2} \rightarrow 6p_{1/2}$ electric dipole-forbidden transition in atomic rubidium. The experiments were carried out in a rubidium vapor cell using Doppler-free optical-optical…
We study nonlinear optical effects in the laser excitation of Rydberg states. $5S_{1/2}$ and $5P_{3/2}$ levels of $^{85}$Rb are strongly coupled by a strong laser field and probed by a weak laser tuned to the $5P_{3/2} - 44D$ Rydberg…
Direct frequency-comb spectroscopy is used to probe the absolute frequencies of $6S_{1/2}$-$8S_{1/2}$ two-photon transitions of atomic cesium in hot vapor environment. By utilizing the coherent control method of temporally splitting the…