Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userWatt-level blue light for precision spectroscopy, laser cooling and trapping of strontium and cadmium atoms
65
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
High-power and narrow-linewidth laser light is a vital tool for atomic physics, being used for example in laser cooling and trapping and precision spectroscopy. Here we produce Watt-level laser radiation at 457.49 nm and 460.86 nm of respective relevance for the cooling transitions of cadmium and strontium atoms. This is achieved via the frequency doubling of a kHz-linewidth vertical-external-cavity surface-emitting laser (VECSEL), which is based on a novel gain chip design enabling lasing at > 2 W in the 915-928 nm region. Following an additional doubling stage, spectroscopy of the $^1S_0to{}^1P_1$ cadmium transition at 228.89 nm is performed on an atomic beam, with all the transitions from all eight natural isotopes observed in a single continuous sweep of more than 4 GHz in the deep ultraviolet. The absolute value of the transition frequency of Cd-114 and the isotope shifts relative to this transition are determined, with values for some of these shifts provided for the first time
rate research
Read More
Ultracold CH radicals promise a fruitful testbed for probing quantum-state controllable organic chemistry. In this work, we calculate CH vibrational branching ratios (VBRs) and rotational branching ratios (RBRs) with ground state mixing. We subsequently use these values to inform optical cycling proposals and consider two possible radiative cooling schemes using the $X^{2}Pi leftarrow A^{2}Delta$ and $X^{2}Pi leftarrow B^{2}Sigma^{-}$ transitions. As a first step towards laser cooled CH, we characterize the effective buffer gas cooling of this species and produce $sim5times10^{10}$ CH molecules per pulse with a rotational temperature of 2(1) K and a translational temperature of 7(2) K. We also determine the CH-helium collisional cross section to be $2.4(8)times10^{-14}$ cm$^{2}$. This value is crucial to correctly account for collisional broadening and accurately extract the in-cell CH density. These cold CH molecules mark an ideal starting point for future laser cooling and trapping experiments and tests of cold organic chemistry.
We present the accurate measurement of the frequency of the $7S-7P$ laser-trapping transition for three francium isotopes. Our approach is based on an interferometric comparison to deduce the unknown laser frequency from a secondary laser frequency-standard. After careful investigation of systematics, with samples of about 100 atoms the final accuracy reaches 8 MHz, an order of magnitude better than the best previous measurement for $^{210}$Fr, and opens the way to improved tests of the theoretical computation of Fr atomic structure.
Continuous wave (CW) lasers are the enabling technology for producing ultracold atoms and molecules through laser cooling and trapping. The resulting pristine samples of slow moving particles are the de facto starting point for both fundamental and applied science when a highly-controlled quantum system is required. Laser cooled atoms have recently led to major advances in quantum information, the search to understand dark energy, quantum chemistry, and quantum sensors. However, CW laser technology currently limits laser cooling and trapping to special types of elements that do not include highly abundant and chemically relevant atoms such as hydrogen, carbon, oxygen, and nitrogen. Here, we demonstrate that Doppler cooling and trapping by optical frequency combs may provide a route to trapped, ultracold atoms whose spectra are not amenable to CW lasers. We laser cool a gas of atoms by driving a two-photon transition with an optical frequency comb, an efficient process to which every comb tooth coherently contributes. We extend this technique to create a magneto-optical trap (MOT), an electromagnetic beaker for accumulating the laser-cooled atoms for further study. Our results suggest that the efficient frequency conversion offered by optical frequency combs could provide a key ingredient for producing trapped, ultracold samples of natures most abundant building blocks, as well as antihydrogen. As such, the techniques demonstrated here may enable advances in fields as disparate as molecular biology and the search for physics beyond the standard model.
We investigate cooling mechanisms in magneto-optically and magnetically trapped erbium. We find efficient sub-Doppler cooling in our trap, which can persist even in large magnetic fields due to the near degeneracy of two Lande g factors. Furthermore, a continuously loaded magnetic trap is demonstrated where we observe temperatures below 25 microkelvin. These favorable cooling and trapping properties suggest a number of scientific possibilities for rare-earth atomic physics, including narrow linewidth laser cooling and spectroscopy, unique collision studies, and degenerate bosonic and fermionic gases with long-range magnetic dipole coupling.
We describe the operation of two GaN-based diode lasers for the laser spectroscopy of gallium at 403 nm and 417 nm. Their use in an external cavity configuration enabled the investigation of absorption spectroscopy in a gallium hollow cathode. We have analyzed the Doppler broadened profiles accounting for hyperfine and isotope structure and extracting both the temperature and densities of the neutral atomic sample produced in the glow discharge. We have also built a setup to produce a thermal atomic beam of gallium. Using the GaN-based diode lasers we have studied the laser induced fluorescence and hyperfine resolved spectra of gallium.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
