L. A. Hackel

Molecular‐beam‐stabilized argon laser

The frequency of a 5145‐A argon‐ion laser has been locked to an absorption line in a molecular beam of I2. The drift of the laser frequency was less than 20 kHz or Δν/ν<3 × 10−11 for the duration of a run which lasted about 20 min. A molecular‐beam external reference is attractive because transitions observed in the isolated conditions in the beam do not suffer shifts due to collisions or collisional broadening and, if the molecular beam is excited orthogonally, Doppler broadening can be virtually eliminated.

Jet stream cw dye laser for high‐resolution spectroscopy

A stable single‐frequency jet stream cw dye laser has been used to obtain an absorption spectrum of the hyperfine structure of I2127 in a molecular beam with a resolution of 5 parts in 109.

High‐resolution spectroscopy of I2 using laser‐molecularbeam techniques

Laser‐molecular‐beam techniques have been used to observe the hyperfine structure of molecular I2. A 5145‐A argon laser, tuneable over 0.05 A, is used to induce fluorescence in a molecular beam of I2. The measured width of the individual I2 transitions is 3 MHz, i.e., a resolution of 5×10−9. The natural width of the lines has been estimated to be less than 800 kHz.

Laser-molecular beam measurement of hyperfine structure in the I2 spectrum

Abstract Very high resolution measurements of hyperfine structure on the P(13) and R(15), 43−0, 3 gp 0 + u ← 1 Σ g + transitions in iodine 127 were made using laser molecular beam spectroscopy. The observed linewidth was 300 kHz (fwhm) giving a resolution of 5 × 10−10 The observed spectrum was fitted to obtain a quadrupole coupling strength difference of ΔeQq = 1906 ± 2 MHz and a spin rotation interaction strength difference of ΔCI = 181 ± 7 kHz between the upper and lower levels of the P(13) transition. For the R (15) transition ΔeQq = 1905 ± 2 MHz and ΔCI = 167 ± 5 kHz.

Molecular Beam Stabilized Multiwatt Argon Lasers

Multiwatt Argon Lasers have been short-term and long-term stabilized. The laser line width has been reduced from 20 MHz to about 10 kHz and a long term stability of 7 × 10-14 has been achieved by using an I2 molecular beam as a reference. Frequency reproducibility of 1.5 × 10-12 has been demonstrated.

Precision Measurement Of Hyperfine Structure In I[sub]2[/sub]

In this paper we report precision studies of I2127 hyperfine structure using laser molecular-beam techniques. A single-frequency 5145 Å argon laser tunable over 0.1 Å was used to excite a molecular beam of 12 at right angles. The induced fluorescence was collected by a lens system and focused onto a photomultiplier. The I2 transitions excited were the hyperfine compo-nents of the P(13) and R(15), 43-0 lines between the z, and 31-1 electronic states. go u The hyperfine frequency spacings were precisely determined by counting the beat frequency between two lasers that were long-term stabilized to various hyperfine lines. The standard deviation of the measurements was approximately 25 kHz. The measured spectrum was fitted to obtain a quadrupole coupling strength difference AeQq= 1894.48 . 36 MHz and a spin-rotation interaction strength difference AC, = 190.7 ± 1.5 kHz between the upper and lower levels of the P(13) transition. For the R(15) transition, we obtained AeQq = 1894. 66 ± .40 MHz and ACI = 187.1 ± 2. 0 kHz. High-resolution line - shape studies were performed using a long-term stabilized laser and an acousto-optic tuning method. The measured width of the individual I2 transi-tions was 140 kHz (FWHM). By taking into account broadening from the geometric Doppler width, laser jitter, and other small effects, an estimate of 70 kHz (FWHM) for the natural linewidth was obtained which was in excellent agreement with lifetime mea-surements. Attempts to fit the observed line shapes showed clear Lorentzian features. Taking account of the natural linewidth, the instrumental resolution was ≈70 kHz or one part in 1010.

Precision Measurement Of Hyperfine Structure In I2

In this paper we report precision studies of I2127 hyperfine structure using laser molecular-beam techniques. A single-frequency 5145 Å argon laser tunable over 0.1 Å was used to excite a molecular beam of 12 at right angles. The induced fluorescence was collected by a lens system and focused onto a photomultiplier. The I2 transitions excited were the hyperfine compo-nents of the P(13) and R(15), 43-0 lines between the z, and 31-1 electronic states. go u The hyperfine frequency spacings were precisely determined by counting the beat frequency between two lasers that were long-term stabilized to various hyperfine lines. The standard deviation of the measurements was approximately 25 kHz. The measured spectrum was fitted to obtain a quadrupole coupling strength difference AeQq= 1894.48 . 36 MHz and a spin-rotation interaction strength difference AC, = 190.7 ± 1.5 kHz between the upper and lower levels of the P(13) transition. For the R(15) transition, we obtained AeQq = 1894. 66 ± .40 MHz and ACI = 187.1 ± 2. 0 kHz. High-resolution line - shape studies were performed using a long-term stabilized laser and an acousto-optic tuning method. The measured width of the individual I2 transi-tions was 140 kHz (FWHM). By taking into account broadening from the geometric Doppler width, laser jitter, and other small effects, an estimate of 70 kHz (FWHM) for the natural linewidth was obtained which was in excellent agreement with lifetime mea-surements. Attempts to fit the observed line shapes showed clear Lorentzian features. Taking account of the natural linewidth, the instrumental resolution was ≈70 kHz or one part in 1010.