Showing papers on "Laser linewidth published in 1976"
TL;DR: In this article, a method of obtaining narrow absorption lines is proposed, based on a simple property of accelerated beams, which would yield a resolution of a few megahertz at optical frequencies.
277 citations
TL;DR: In this paper, a third-order perturbation calculation of line shapes in laser spectroscopy based on the density-matrix formalism is presented, where a new feature of this theory is the inclusion of the Gaussian spatial structure of the laser beams.
Abstract: We present a third-order perturbation calculation of line shapes in laser spectroscopy based on the density-matrix formalism. The new feature of this theory is the inclusion of the Gaussian spatial structure of the laser beams. We study the linewidth as a function of relaxation and transit times. A shift is found when the wave fronts are not flat. General line-shape formulas are given as well as approximate formulas valid in various domains.
180 citations
TL;DR: The second-order correlation function for light scattered at resonance from a two-level atom is calculated in this article, and the measurement of intensity correlations employing either homodyne or heterodyne techniques provides a novel approach for the extraction of linewidth and splitting frequencies.
Abstract: The second-order correlation function for light scattered at resonance from a two-level atom is calculated The measurement of intensity correlations employing either homodyne or heterodyne techniques provides a novel approach for the extraction of linewidth and splitting frequencies
161 citations
TL;DR: In this article, a new technique for use in coherent anti-Stokes Raman scattering experiments allows the simultaneous generation of an entire Q-branch spectrum of the anti-stokes radiation from a molecular gas using a single laser pulse.
Abstract: A new technique for use in coherent anti‐Stokes Raman scattering experiments allows the simultaneous generation of an entire Q‐branch spectrum of the anti‐Stokes radiation from a molecular gas using a single laser pulse. With this technique the stringent requirements of the previous techniques concerning laser linewidth and frequency stability are significantly relaxed. The excellent temporal resolution (20 nsec) makes the technique very attractive for temperature and concentration measurements of molecular gases, even in nonstationary media.
152 citations
147 citations
TL;DR: In this article, the fundamental relationships for linewidth and resolution for all forms of ion cyclotron resonance spectroscopy are derived. And the theoretical basis for the FT-ICR spectral segment extraction technique is described, for use in enhancing FT-ICR resolution by several orders of magnitude.
Abstract: The fundamental relationships for linewidth and resolution for all forms of ion cyclotron resonance spectroscopy are derived. Mass resolution and frequency resolution are shown to be numerically identical in all forms of ion cyclotron resonance spectroscopy. Theoretical Fourier transform ion cyclotron resonance (FT–ICR) spectral line shape has been calculated for the low‐pressure limit in which there are essentially no ion–molecule collisions during the observation period. Absorption, dispersion, and magnitude (absolute‐value) line shapes are illustrated and discussed. FT–ICR linewidth and resolution are calculated as a function of ionic mass and charge, applied magnetic field strength, and data acquisition time, for various linewidth criteria, and the results are tabulated. FT–ICR linewidth and resolution are then expressed in terms of ionic mass, computer data storage size, and minimum specified ionic mass in the FT–ICR mass range, for various linewidth criteria, and the results are tabulated. Next, FT–ICR upper mass limit is calculated as a function either of ionic charge, applied magnetic field strength, and data acquisition time, or computer data storage size and minimum specified ionic mass in the FT–ICR mass range, and the results are tabulated for several linewidth criteria. For the same observation time and linewidth criterion, FT–ICR zero‐pressure resolution is 47% better than with conventional ’’drift’’ cell or ’’trapped‐ion’’ cell ICR detection. Finally, the theoretical basis for the FT–ICR spectral segment extraction technique is described, for use in enhancing FT–ICR resolution by several orders of magnitude.
142 citations
TL;DR: In this paper, a high-resolution study of the resonant scattering response of Cu metal in the x-ray regime was performed using synchrotron radiation, and it was shown that the linewidth of the emitted radiation becomes narrower than the lifetime-limited width of the fluorescent radiation.
Abstract: Intense tuneable synchrotron radiation was used to perform a high-resolution study of the resonant scattering response of Cu metal in the x-ray regime. One finds in the transition regime from fluorescence to resonant scattering that the linewidth of the emitted radiation becomes narrower than the lifetime-limited width of the fluorescent radiation.
141 citations
TL;DR: In this paper, the authors used the phenomenon of laser-induced molecular photodissociation to determine the homogeneous linewidth at 2 K of the origin (zero-phonon line) and a vibronic transition in the mixed-crystal absorption spectrum of dimethyl s-tetrazine in durene.
Abstract: We have used the phenomenon of laser-induced molecular photodissociation to determine the homogeneous linewidth at 2 K of the origin (zero-phonon line) and a vibronic transition in the mixed-crystal absorption spectrum of dimethyl s-tetrazine in durene. From the measured 55-MHz (upper limit) homogeneous width of the origin we conclude that in the vibrationless excited state coherence persists at least during the 6-nsec lifetime. The 29-GHz homogeneous vibronic linewidth is ascribed to vibrational relaxation.
119 citations
103 citations
TL;DR: A simple theory of the homogeneous broadening of vibrational lines in the IR and Raman spectra of molecules in liquids is presented in this article, which considers the relationship between the linewidth and excited state lifetime, parameters which may now be independently measured.
94 citations
TL;DR: In this paper, a tunable pulsed laser is employed to selectively excite rare-earth ions in glass and the resulting line-narrowed fluorescence is used to measure the site-to-site variations in crystalline Stark splitting, radiative lifetime, homogeneous linewidth, and ion-ion energy transfer.
TL;DR: In this article, the homogeneous width of the pure electronic transition by hole-burning method in the contour of a narrow (3-4 cm -1 ) inhomogeneously broadened component of the 0-0 multiplet of H 2 -phthalocyanine in n-octane at 5 K was measured.
TL;DR: Forty-MHz wide fluorescence has been seen using the 80MHz wide 2852 A transition of 24 Mg atoms in an atomic beam irradiated by a doubled cw dye laser.
TL;DR: In this article, the authors present a completely classical analysis of the small-signal regime of a free-electron laser and show that the amplification is due to stimulated scattering produced by a bunching of the electron distribution.
Abstract: We present a completely classical analysis of the small-signal regime of a free-electron laser. It is explicitly shown that the amplification is due to stimulated scattering produced by a bunching of the electron distribution.
TL;DR: In this paper, single crystal thin films of yttrium iron garnet were grown on gadolinium gallium garnet (GGG) substrates by the isothermal dipping method of liquid phase epitaxy.
TL;DR: In this paper, the effect of spectral linewidth and splitting on the coherence of excitation undergoing transfer was investigated in both real and model systems, and several examples derived from both real-and model systems were presented.
TL;DR: In this article, a computer-controlled microwave spectrometer has been used to record the frequency dependence of the absorption of the J=2←1 transition of OCS under varying conditions of pressure, temperature, and microwave power.
Abstract: A computer‐controlled microwave spectrometer has been used to record the frequency dependence of the absorption of the J=2←1 transition of OCS under varying conditions of pressure, temperature, and microwave power. From least‐squares fits of the data to Lorentzian line shapes, a variety of linewidths and linewidth parameters have been deduced. The linewidth parameter for the J=2←1 transition of 16O12C32S in the ground vibrational state has been determined to be 6.03±0.05 MHz/torr. The ratios of linewidth parameters for this transition for several other species to that for the ground state of 16O12C32S are: 16O12C34S, ground state, 0.987±0.003; 16O13C32S, ground state, 0.991±0.005; 18O12C32S, ground state, 0.966±0.018; 16O12C32S, v3=1, 1.024±0.026; 16O12C32S, v2l=2°, 0.978±0.003. The linewidth parameter for the ground state of the parent species was determined to be inversely proportional to the absolute temperature in the range 297–346 K. From comparison of theoretical and experimental power‐broadened lin...
TL;DR: In this article, the proper application of the established theory of electron-ripplon scattering for electrons trapped on helium correctly predicts the absolute linewidth, as a function of external electric field, observed in a recent plasmon experiment.
Abstract: We show that the proper application of the established theory of electron-ripplon scattering for electrons trapped on helium correctly predicts the absolute linewidth, as a function of external electric field, observed in a recent plasmon experiment.
TL;DR: In this article, the effects of two different frequencies are considered and the residual Doppler width of the two-photon transition is less than the natural linewidth, the previous results are essentially regained.
Abstract: For pt.I see ibid., vol.8, p.1795 (1975) where the theory of Doppler-free two-photon transitions was discussed for the case of one single laser frequency. Here, the effects of two different frequencies are considered. When the residual Doppler width of the two-photon transition is less than the natural linewidth, the previous results are essentially regained. For large residual Doppler shifts, the absorption profile is a power-broadened Lorentzian if the frequency of the probe field is larger than the frequency of the strong field. In the opposite case, the absorption peak splits because of the AC Stark effect. The high-intensity distortions are minimized when equal frequencies can be used. Power-dependent shifts do not ordinarily occur with a resonantly tuned intermediate level. Some modifications of the spectra are introduced by phase-disturbing collisions.
TL;DR: In this article, the frequency shift and linewidth of longitudinal Brillouin scattering lines are given in the range of 20-1000°C and the critical index of damping is found equal to 0.8 in the α-phase and 1.9 in the β-phase, respectively.
TL;DR: In this article, the magnetic excitation spectrum of ferromagnetic Pd3Fe (Tc=499K) has been measured at 293, 373, 423, 473 and 573K by neutron inelastic scattering techniques.
Abstract: Measurements of the magnetic excitation spectrum of ferromagnetic Pd3Fe (Tc=499K) have been made at 293, 373, 423, 473 and 573K by neutron inelastic scattering techniques. Constant energy and constant momentum transfer modes of operation were employed with reduced wavevectors between 0.11 and 0.40 in the ( zeta 00) direction. At 293K a single branch of the dispersion relation for magnetic excitations is observed which is characterized by an exchange stiffness of 52.7+or-2.7 THz AA2. The intrinsic linewidth is a strong function of wave vector and varies from 0.0+or-0.5 THz at zeta =0.13 to 2.5+or-0.5 THz at zeta =0.30. When the temperature is raised the excitation frequencies fall and the linewidths increase. Between 293 and 473K at zeta =0.3 the frequency falls by a factor of 1.8 and the linewidth increases by the same factor, but a broad inelastic response is still observed. At 473K at wavevectors less than zeta =0.13, the magnetic scattering has the form of a peak of appreciable width centred on zero frequency.
TL;DR: In this article, it was shown that the linewidth of the B-site Mossbauer spectrum of an Fe 3 O 4 single crystal at room temperature is strongly dependent on the direction of the externally applied magnetic field.
TL;DR: In this article, the second and third harmonics of a repetitively pulsed Nd:YAG laser were used to upconvert rhodamine and coumarin dye lasers to the 208-234 nm by mixing with 1064 nm.
Abstract: Sum-frequency generation experiments in which the second harmonics of rhodamine and coumarin dye lasers are upconverted to the 208-234 nm by mixing with 1064 nm are described. The dye lasers were pumped by the second and third harmonics of a repetitively pulsed Nd:YAG laser. Both temperature-tuned and angle-tuned phase matching techniques were used with mixer crystals of ammonium dihydrogen phosphate (ADP) and potassium dihydrogen phosphate (KDP). Tunable light from 246 nm to 259 nm also was generated by mixing the output of a coumarin laser with the 532-nm harmonic of the Nd:YAG laser. Peak powers between about 500 W and 10 kW were obtained, and both theoretical and experimental tuning curves have been determined for these processes. Limitations imposed by mode beating effects in the Nd:YAG laser and by the relatively broad linewidth of the dye lasers are discussed.
TL;DR: In this article, the authors describe the operating characteristics of a compact, frequency tunable, electron-beam-controlled, 15 atmosphere CO 2 laser, which is used to obtain laser line narrowing and continuous tuning within the 10.4 μm and 9.4μm bands of the gain spectrum.
TL;DR: In this paper, the EPR magic angle linewidth and dynamic shift have been measured as a function of frequency in TMMC and the results support strongly the one-dimensional behaviour of the relaxation dynamics of this compound.
TL;DR: In this paper, strong light induced resonance signals, observed at 9.2 and 35 GHz, have been ascribed to cyclotron resonance and the unexpected linewidth increase with frequency is discussed.
TL;DR: A new, simple scheme to tune a double-pass, superradiant dye laser is reported, using a planar cell with a thickness below 100 microm and the absence of a resonant cavity avoids modal structure and ensures improved frequency and intensity stability.
Abstract: A new, simple scheme to tune a double-pass, superradiant dye laser is reported. A
planar cell with a thickness below 100 μm filled with a
highly concentrated (4–5 × 10−3-M/liter)
solution of Rhodamine 6G in ethanol is used. An unsaturated gain value of 1.7
cm−1 has been measured with flashlamp pumping, and the
amplifier has been found to operate at a well saturated regime. Smooth laser
linewidths ranging from broadband, gain narrowed values of 10 nm to narrowband
values of 8 GHz have been achieved by using appropriate frequency dispersive
feedback elements and suitable cell thickness. A 5-GHz output has been observed
with a 25-μm gap cell. The absence of a resonant cavity
avoids modal structure and ensures improved frequency and intensity stability.
The reported configuration should be scalable up as far as output energy is
concerned. Simultaneous two-wavelength operation is possible. Pumping with a
frequency-doubled Nd-laser should allow a further reduction of the usable cell
thickness with narrower output bandwidths.
TL;DR: In this paper, a 50-MHz pulsed dye laser employing a reflective intracavity beam expander achieves a 50MHz full width at half-maximum (FWHM) linewidth.
Abstract: A repetitively pulsed dye laser employing a reflective intracavity beam expander achieves a 50-MHz full width at half-maximum (FWHM) linewidth. A geometrical technique for partially correcting the expander astigmatism and maintaining cavity stability is derived. The use of reflective cavity elements minimizes cavity losses and eliminates spurious reflections.