Biomedical subjects

P Cancio

Publications and source records attributed to P Cancio.

5 recordsLinked to original sources

PubMed2005

Frequency-comb-based absolute frequency measurements in the mid-infrared with a difference-frequency spectrometer.

We demonstrate the possibility of extending the well-established metrological performance of optical frequency-comb synthesizers to the mid-IR region by phase locking the pump and signal lasers of a difference-frequency source to two near-IR teeth of an optical comb. An uncertainty of 800 Hz (1.1 x 10(-11)) in the absolute frequencies of CO2 transitions near 4.2 microm has been measured by cavity-enhanced saturated-absorption spectroscopy. Prospects for the creation of a new dense set of high-quality molecular frequency standards in the IR are discussed.

Journal Article↗

PubMed2003

Precision frequency measurement of visible intercombination lines of strontium.

We report the direct frequency measurement of the visible 5s(2) 1S0-5s5p 3P1 intercombination line of strontium that is considered a possible candidate for a future optical-frequency standard. The frequency of a cavity-stabilized laser is locked to the saturated fluorescence in a thermal Sr atomic beam and is measured with an optical-frequency comb generator referenced to the SI second through a global positioning system signal. The 88Sr transition is measured to be at 434 829 121 311 (10) kHz. We measure also the 88Sr-86Sr isotope shift to be 163 817.4 (0.2) kHz.

Journal Article↗

PubMed2001

Spatial mode control of radiation generated by frequency difference in periodically poled crystals.

We demonstrate the possibility to control the spatial mode of a narrow-linewidth, continuous-wave, infrared radiation beam generated by difference frequency in a periodically poled crystal. This can be achieved by acting directly on a few experimental parameters. We show that hollow beams can be generated. A numerical routine has been developed and results agree with experimental observations, without requiring any free parameters. The relevance of these results for high-resolution spectroscopy and atom manipulation is discussed.

Journal Article↗

PubMed2001

Search for exchange-antisymmetric states for spin-0 particles at the 10(-11) level.

We set a new upper limit of 1.7x10(-11) to the probability that two spin-0 16O nuclei are in forbidden exchange-antisymmetric states, testing the validity of fundamental principles of quantum mechanics. A newly designed difference-frequency spectrometer is used to look for the existence of these states. The experimental test was performed by tuning the spectrometer across a molecular transition of 12C 16O (2) belonging to the rovibrational band at 4.25 microm, connecting the forbidden states (00(0)0,J = 25) and (00(0)1,J = 26).

Journal Article↗

PubMed1999

The Stimulated Raman Spectrum of Symmetric 13C Cyanogen, 13C2N2.

The Raman spectrum of cyanogen 13C214N2 has been investigated at nearly Doppler resolution by means of a stimulated Raman technique. The regions around the bandheads of the nu1 (2260 cm-1) and nu2 (835 cm-1) vibrations have been recorded. Besides the fundamentals, hot bands arising from v5 = 1-3 and v4 = 1 have been observed. A number of strong perturbations have been detected. The spectra have been analyzed and rotational constants for the excited states have been obtained. Computer simulations of the Raman contours have been carried out as a test of the assignments. A few weak DeltaJ = -2 lines have also been observed in the nu1 region.

Journal Article↗