R. Felder

Frequency measurement of the 5S12(F = 3)−5D52(F = 5) two-photon transition in rubidium

Abstract We have measured the frequencies of three diode lasers stabilized on the 5 S 1 2 (F = 3)−5 D 5 2 (F = 5) two-photon transition in rubidium at λ = 778.1 nm, with an uncertainty of 1 kHz, using BNM-LPTF frequency synthesis chain starting from a CO 2 OsO 4 reference laser at 10.3 μm. We show that this frequency chain is able to reach the 10−13 resolution level. After a discussion of the systematic effects that may shift the resonance, the transition frequency is found to be ν = 385 285 142 378.280 ± 2 kHz.

Towards an accurate frequency standard at λ778 nm using a laser diode stabilized on a hyperfine component of the Doppler-free two-photon transitions in rubidium

Abstract Two systems are built in which a commercially available GaAlAs laser diode is stabilized on a hyperfine component of the 5S 1 2 −5D( 3 2 , 5 2 ) two-photon transitions in rubidium at λ=778 nm (v=385 THz). Some preliminary metrological results are presented. The frequency repeatability has been found to be of 200 Hz (5.2 parts in 1013) and a short-term frequency stability of 3×10-13/ τ /gt up to 2000 s is currently obtained.

Performance of a GaAlAs laser diode stabilized on a hyperfine component of two-photon transitions in rubidium at 778 nm

The absolute frequency measurement of each hyperfine component of the 5S3/2 and 5S5/2 levels in rubidium was done at ENS more than one year ago using Ti-Sa lasers. We built two devices based on diode lasers to study some metrological properties. We measure the frequency differences between hyperfine components of the 5S5/2 level and we calculate the corresponding hyperfine constants. We also measure the frequency interval between the 5S3/2 and 5S5/2 levels using a Schottky diode. The measured stability in terms of Allan variance is 3*10-13t-1/2 up to 2000 s. The light shift is investigated and the difference between our two systems is 1.7 kHz. The repeatability of one system is better than 10-12 and will allow the absolute frequency measurement at this level via the LPTF frequency synthesis chain.

A potential new frequency/wavelength standard at 778 nm: Doppler free two-photon transitions in rubidium

We have stabilized two laser diodes on the hyperfine components of the 5D/sub 3/2/ and 5D/sub 5/2/ two-photon transitions in natural rubidium (v=385 THz). We have carefully investigated the metrological features of these devices. So far we obtain a frequency stability in terms of the Allan variance of 3.10/sup -13/./spl tau//sup - 1/2 / up to 2000 s and a frequency repeatability of the order of 10/sup -12/. The frequency difference between the two devices is 1.7 kHz under identical operating conditions.<<ETX>>

Absolute frequency measurement of a diode laser locked on a hyperfine component of 5S1/2-5D5/2 two-photon transitions of rubidium (lambda equals 778.1 nm, nu equals 385.3 THz)

A frequency chain, derived from the one used to measure the absolute frequency ((nu)

Towards a frequency measurement of the Rydberg constant using the 2S-8S and 2S-8D transitions of hydrogen

= 473 THz) of the He-Ne/I2 optical standard, is currently being implemented in order to measure the frequency of a diode laser stabilized on the two-photon transition of rubidium vapor. The measurement scheme is based on the comparison of the frequency of this near-IR potential secondary standard to the 13th harmonic frequency of the R(12)-CO2/OsO4 LPTF secondary standard at (nu) equals 29.096 THz. Recent results on the frequency synthesis are reported, enabling the testing of long-term stability of this Rb-locked system with respect to the IR reference standard.

An accurate optical frequency measurement system at telecommunication region

A very precise measurement of the Rydberg constant is performed using a direct-frequency comparison of the 2S-8S and 2S-8D two-photon transitions in atomic hydrogen with the difference of two optical standards connected to a frequency chain. >

Precise frequency measurement of the 2S-8S/8D transtions in atomic hydrogen: New determination of the Rydberg constant.

We are now developing an accurate optical frequency measurement system at the telecommunication region using an optical frequency standard with Doppler-free acetylene absorption and a mode-locked fiber laser.