ABSTRACT
We synthesized tunable far-infrared radiation at frequencies higher than 9 THz (300 cm (-1)) by mixing CO(2) laser, (15)NH(3) laser, and microwave radiation in a W-Co metal-insulator-metal diode. We used this farinfrared radiation to accurately measure torsion-rotation transitions of CH(3)OH in the 8-9-THz region. We also measured the frequency of the aP(7, 3) (15)NH(3) laser transition.
ABSTRACT
We generated tunable far-infrared radiation by mixing CO(2) -laser,(15)NH(3) -laser, and microwave radiations in a W-Co metal-insulator-metal diode. We used this far-infrared radiation to measure accurately the torsion-rotation transitions of CH(3)OH in the 6-8-THz region.
ABSTRACT
We report what we believe is the first observation of continuous-wave far-infrared laser emission from water vapor and from ammonia optically pumped by a CO laser.
ABSTRACT
We present a novel technique for resonantly pumping a continuous-wave far-infrared NH(3) laser with a linetunable mid-infrared NH(3) laser that is optically pumped by a CO(2) laser. In this two-step process we first convert 10-microm CO(2) laser photons into 11-13-microm NH(3) laser photons, which are then converted into 60-400-microm photons in a far-infrared NH(3) laser. Continuous-wave laser action on 10 far-infrared lines of (15)NH(3), including four new ones, has been obtained with a single CO(2) laser pump line.
ABSTRACT
We report 16 new laser lines generated in a short-wavelength far-infrared Fabry-Perot laser cavity. The CO(2) pump laser is coupled into the far-infrared laser outside the far-infrared laser mode, and the cavity uses a 45 degrees adjustable output coupling mirror; this combination results in a low-loss Fabry-Perot cavity for wavelengths below 150 microm. The new lines are of medium and strong intensity and have wavelengths in the region 26.2-125.7 microm.
ABSTRACT
The first experimental observations to our knowledge of sub-Doppler linewidths in a cell made using tunable far-infrared radiation are reported. A double-resonance scheme has been used, combining CO(2)-laser infrared radiation with tunable far-infrared radiation to observe a sub-Doppler line shape in an excited vibrational state of CH(3)OH.
ABSTRACT
The frequency of the 170.6-microm cw CH(3)OH optically pumped laser emission has been remeasured at different pressures without observing the pressure shift observed by Lawandy and Koepf [Opt. Lett. 5, 383 (1980)]. The far-infrared frequency was synthesized with two stabilized CO(2) lasers. No measurable pressure shift over the operating pressure range of the laser was observed, and the frequency was confirmed to be 1 757 526.3 MHz. However, competing lasing lines were found to produce spurious effects on the frequency. These effects may explain the apparent shifts.
ABSTRACT
The o hyperfine component of the (127)I(2) 17-1 P(62) transition at 520 THz (576 nm) in iodine was measured with respect to the CH(4)-stabilized 88-THz He-Ne laser. A 26-THz CO(2) laser, a color-center laser at 130 THz, and a He-Ne laser at 260 THz were used as transfer oscillators. The measured I(2) frequency was 520 206 808.547 MHz with a total fractional uncertainty of 1.6 x 10(-10). The 1.15-microm (20)Ne Lamb-dip-stabilized laser frequency was 260 103 249.26 MHz with a total fractional uncertainty of 3.1 x 10(-10).
ABSTRACT
The absolute frequency of the 473-THz He-Ne laser (633 nm), stabilized on the g or i hyperfine component of the (127)I(2) 11-5 R(127) transition, was measured by comparing its frequency with a known frequency synthesized by summing the radiation from three lasers in a He-Ne plasma. The three lasers were (1) the 88-THz CH(4)-stabilized He-Ne laser (3.39 microm), (2) a 125-THz color-center laser (2.39 microm) with its frequency referenced to the R(II)(26) (13)C(18)O(2)laser, and (3) the 260-THz He-Ne laser (1.15 microm) referenced to an I(2)-stabilized dye laser at 520 THz (576 nm). The measured frequencies are 473 612 340.492 and 473 612 214.789 MHz for the g and i hyperfine components, respectively, with a total uncertainty of 1.6 parts in 10(10). The frequency of the i component adjusted to the operating conditions recommended by the Bureau International des Poids et Mesures is 473 612 214.830 +/- 0.074 MHz.
ABSTRACT
Absolute infrared frequency measurement has been extended to 260 THz with the measurement of the strong 1.15-microm laser line in (20)Ne. The frequency was synthesized in nonlinear crystals of CdGeAs(2) and Ag(3)AsS(3) from stabilized CO(2) lasers and the 1.5-microm laser line in (20)Ne. The measured frequency is nu(20)Ne, 1.15 microm = 260.103 284(30) THz.
ABSTRACT
Direct-frequency measurements have been extended into the visible region of the electromagnetic spectrum. The visible frequencies were synthesized by generating the second harmonic of the recently measured 260-THz (20)Ne, 1.15-microm laser with a LiNbO(3) crystal. The absolute frequencies of ten hyperfine components of (127)I(2) near 520 THz are reported.
ABSTRACT
Twenty-five new, cw, FIR lines from CH(2)F(2), optically pumped by a CO(2) laser, have been found, using a variablecoupling, open-structure resonator. Accurate wavelength measurements have been made on the 47 known CH(2)F(2) lines. The new lines are fairly uniformly distributed over a wide range, from 105 to 1448 microm.