K.J. Siemsen

Absolute frequency measurements of N2O laser transitions

Abstract The absolute frequencies of 33 P- and R-branch lines of the N 2 O, 00°1–10°0 laser band have been measured by heterodyning with known CO 2 laser frequencies of the 00°1 – 10°0 band in a tungsten-nickel diode. These measurements were used to calculate more precise values for the band centre and for the rotational constants.

CO2 Wavelengths and the Velocity of Light

Abstract : New measurements of CO2 laser wavelengths in the 9 micrometer and 10 micrometer bands are reported accurate to about 2X10 to the minus 8th power. These are used in combination with Evensons recently reported frequency values to derive a new value for the velocity of light and to update Changs CO2 frequency and wavelength tables. (Author)

New CO2 laser bands in the 9–11‐μm wavelength region

Thirty‐six new lines in the 9–11‐μm wavelength region have been observed in continuous emission from a CO2 laser. These lines are identified as rotation‐vibration transitions in the (00°2‐[10°1, 02°1]I) and (00°2‐[10°1, 02°1]II) bands. Several hundred milliwatts of power have been obtained on most of these transitions.

Precision frequency measurement of the /sup 2/S/sub 1/2/-/sup 2/D/sub 5/2/ transition of Sr/sup +/ with a 674-nm diode laser locked to an ultrastable cavity

We have measured the frequency of the 5s /sup 2/S/sub 1/2/-4d /sup 2/D/sub 5/2/ clock transition of a single Sr ion confined in a Paul trap. A diode laser locked to an ultrastable Fabry-Perot (F-P) cavity was used to probe the transition with a resolution of 3.5 kHz. The absolute frequency was determined from heterodyne measurements referenced to an iodine stabilized HeNe laser and a CO/sub 2/ laser yielding a value for the S-D transition of (444 779 043 963/spl plusmn/30) kHz. This work could lead to the development of a new optical frequency standard at 674 nm.

Heterodyne frequency measurements of CO2 laser hot-band transitions

Careful measurements by means of stabilized CO2 lasers are presented for the frequencies of 28 lines in the P-branch of the 01 0 0-(11 1 0, 03 1 0)I band of (C-13)(0-16)2, observed in laser emission, and three lines in the R-branch, observed in absorption with a diode laser. A significant improvement in the ro-vibrational constants has been obtained from a least squares fit to these data, demonstrating that the laser lines stabilized by natural absorption techniques provide convenient, accurate frequency references near 11.7 microns with an uncertainty of less than 0.1 MHz.

Absolute frequency measurement of a laser at 1556 nm locked to the 5S1/2-5D5/2 two-photon transition in 87Rb

Abstract The frequency of a diode laser system at 193 THz (1556 nm), which is frequency doubled and locked to a two-photon transition in rubidium at 385 THz (778 nm), has been measured with a Cs-based frequency chain and a single Sr + ion standard at 445 THz. The output frequency of the diode laser system was measured to be 192 642 283 183 700 ± 500 Hz. After applying corrections for systematic offsets in the rubidium spectrum, the frequency of the 87 Rb 5S 1/2 ( F g =2)−5D 5/2 ( F e =4) two-photon transition is found to be 385 284 566 370.4 ± 2 kHz.

FIR laser lines of CH 3 OH pumped by CO 2 laser sequence lines

We report on the utilization of a sequence band CO 2 laser as the pumping source for new FIR laser lines of CH 3 OH.

Heterodyne frequency measurements of 13 CO 2 laser hot band transitions

The frequencies of twenty-eight lines in the P-branch of the 01(1)1-[11(1)0,03(1)0](I) band of (13)C(16)O(2), observed in laser emission, and three lines in the R-branch, observed in absorption with a diode laser, have been carefully measured with stabilized CO(2) lasers. A significant improvement in the ro-vibrational constants has been obtained from a least squares fit to these data. The laser lines stabilized by saturated absorption techniques provide convenient, accurate (uncertainty <0.1 MHz) frequency references near 11.7 microm.

Heterodyne frequency measurements and analysis of CO2 laser hot band transitions

Abstract New frequency measurements of molecular lines in the P branch of the 01 1 1-[11 1 0, 03 1 0] I band of 12 C 16 O 2 , observed in laser emission, and lines in the R branch, observed in absorption with a tunable-diode laser, have been made by heterodyne difference frequency techniques, with stabilized CO 2 lasers generating the reference frequencies. The data obtained, plus additional results of measurements made by two other groups of researchers, were combined in a leastsquares fit to obtain improved rovibrational constants for this band. The new constants predict more reliably the frequencies of both the P - and R -branch transitions. A table of transition frequencies and their estimated uncertainties is given for this band.

Absolute heterodyne frequency measurement of the 88 Sr + 455-THz S–D single ion transition

A system is described for the absolute frequency measurement of a laser source at 445 THz probing a narrow resonance of a trapped single ion of strontium. The 474-THz frequency from a laser referenced to an iodinestabilized helium-neon laser and a known 29-THz frequency from a saturation-stabilized carbon dioxide laser are mixed in an AgGaS(2) nonlinear crystal to synthesize the 445-THz radiation. A preliminary measurement of the (88)Sr(+) 5s(2)S(1/2)-4d(2)D(5/2) center frequency yielded a frequency of 444779044.14 +/- 0.39 MHz (1sigma).