Showing papers on "Laser linewidth published in 1977"
TL;DR: In this paper, a simple cavity design for nitrogen-laser-pumped dye lasers is presented, achieving a linewidth of 0.08 cm−1 with a single dispersive element and without any intracavity beam expansion.
Abstract: A new simple cavity design for nitrogen‐laser‐pumped dye lasers is presented. Narrowband operation is achieved with a single dispersive element and without any intracavity beam expansion. The dispersive element is a diffraction grating used near grazing incidence with an additional mirror, instead of the usual Littrow arrangement. The large angular dispersion obtained results in a linewidth of 0.08 cm−1. The typical peak power obtained is 4 kW with 50 kW in the pump beam. Calculations of linewidth based on single‐pass estimates are presented and are found to be in good agreement with experimental results.
235 citations
TL;DR: In this paper, the homogeneous linewidth of the 0-0 band of the S1←S0 transition of freebase porphyrin (H2P) in an n-octane matrix and its temperature dependence (T=1.5-4.2 K) have been measured by means of photochemical hole-burning.
Abstract: The homogeneous linewidth of the 0–0 band of the S1←S0 transition of free‐base porphyrin (H2P) in an n‐octane matrix and its temperature dependence (T=1.5–4.2 K) have been measured by means of photochemical hole‐burning. The linewidth extrapolated to T=0 is ∼9 MHz for the two types of sites which have been investigated, and it appears to be determined entirely by the decay time of the emitting state S1 (17 ns). The temperature dependence of the linewidth is strongest for the thermodynamically less stable sites. The increase in linewidth with temperature may arise from a relaxation process involving a low frequency resonance mode (∼5 cm−1) localized at the H2P molecules. At 77 K the homogeneous linewidths are comparable to the inhomogeneous widths of 3–4 cm−1; hence, hole–burning is no longer observed.
156 citations
TL;DR: The preliminary results suggest that cw SRS is a potentially powerful alternative to conventional spontaneous Raman scattering, with resolution limited solely by laser linewidth and sensitivity independent of resolution requirements.
Abstract: It is demonstrated that stimulated Raman spectroscopy (SRS) can be performed using cw dye lasers at power levels over six orders of magnitude smaller than those generally associated with pulsed stimulated Raman studies. The preliminary results suggest that cw SRS is a potentially powerful alternative to conventional spontaneous Raman scattering, with resolution limited solely by laser linewidth and sensitivity independent of resolution requirements.
89 citations
TL;DR: A method is presented for high-range resolution measurement of the backscatter from a scattering medium located in one arm of an interferometer that relies on the availability of a cw laser with a significant linewidth.
Abstract: A method is presented for high-range resolution measurement of the backscatter from a scattering medium located in one arm of an interferometer. The technique is interferometric in nature and relies on the availability of a cw laser with a significant linewidth. The measurement is based on observing coherent interference (equivalent to white-light fringes) between the return from the two arms of the interferometer for the portion of the backscatter that makes the path lengths equal. Experimental results are presented for backscatter from a turbid medium and from a stack of glass plates.
84 citations
TL;DR: A comparison of experimental and theoretical image profiles is given, showing good agreement with theory for a 0.9 N.A. and linewidths as small as 0.5 microm; the correspondence between the edge location and the 25% threshold appears to be nearly invariant.
Abstract: A theoretical model of the optical microscope based on the theory of partial coherence is used to predict the image profiles of lines on IC photomasks and assess factors contributing to measurement errors for different conditions of microscope operation. A comparison of experimental and theoretical image profiles is given, showing good agreement with theory for a 0.9 N.A. and linewidths as small as 0.5 microm. The primary sources of differences appear to be edge quality and accuracy of focus. The theory indicates that for well-corrected microscope optical systems, spectrally filtered to eliminate longitudinal chromatic aberration and chromatic difference of magnification, accurate determinations of linewidth may be made from the image profile using a threshold of 25% of maximum intensity (corrected for finite background transmittance in the opaque region). The correspondence between the edge location and the 25% threshold appears to be nearly invariant with small amounts of defocus and spherical aberration as well as variation in the numerical aperture of the condenser.
77 citations
TL;DR: In this article, the authors used the fluorescence line narrowing technique to determine the homogeneous width of the 5D(0) to 7D (0) resonance fluorescence lines of Eu(3+) in an amorphous silicate matrix as a function of laser excitation wavelength and temperature.
Abstract: : The fluorescence line narrowing technique (FLN) is used to determine the homogeneous width of the 5D(0) to 7D(0) resonance fluorescence line of Eu(3+) in an amorphous silicate matrix as a function of laser excitation wavelength and temperature (200-350 K). A smooth increase in delta nu sub hom is observed as the excitation wavelength is decreased across the inhomogeneous profile (excitation of sites of progressively higher average crystal field. The combined temperature and excitation wavelength dependence identify the broadening mechanism as a two-phonon Raman scattering process and suggest that the observed increase of delta nu sub hom with increasing excitation energy is due to stronger electron-phonon coupling at sites of stronger crystal field. (Author)
69 citations
01 Aug 1977
TL;DR: In this article, the authors used the fluorescence line narrowing technique to determine the homogeneous width of the 5D(0) to 7D (0) resonance fluorescence lines of Eu(3+) in an amorphous silicate matrix as a function of laser excitation wavelength and temperature.
Abstract: : The fluorescence line narrowing technique (FLN) is used to determine the homogeneous width of the 5D(0) to 7D(0) resonance fluorescence line of Eu(3+) in an amorphous silicate matrix as a function of laser excitation wavelength and temperature (200-350 K). A smooth increase in delta nu sub hom is observed as the excitation wavelength is decreased across the inhomogeneous profile (excitation of sites of progressively higher average crystal field. The combined temperature and excitation wavelength dependence identify the broadening mechanism as a two-phonon Raman scattering process and suggest that the observed increase of delta nu sub hom with increasing excitation energy is due to stronger electron-phonon coupling at sites of stronger crystal field. (Author)
64 citations
TL;DR: In this paper, the frequencies of 46 CW laser lines with wavelengths between 0.1 and 0.7 mm have been measured by heterodyne methods, with threshold pump powers of 3 W or less.
Abstract: The frequencies of 46 CW laser lines commonly used for submillimeter spectroscopy, with wavelengths between 0.1 and 0.7 mm, have been measured by heterodyne methods. All the fines are optically pumped by a CO 2 laser, with threshold pump powers of 3 W or less. The precision of measurement, limited by the laser linewidth, is typically ± 1 part per million.
60 citations
TL;DR: In this article, complex spectral and laser properties are studied for crystals of the K5Bi1−xNdx(MoO4)4 system, in the whole concentration region of x = 0 to 1.
Abstract: Complex spectral and laser properties are studied for crystals of the K5Bi1−xNdx(MoO4)4 system, grown by the Czochralski technique, in the whole concentration region of x = 0 to 1. By the analysis of absorption and luminescence spectra the crystal field splitting scheme of the lowest 4F3/2 and 4I9/2−15/2 manifolds and their Stark components are established. Weak concentration quenching of luminescence is observed. The luminescence lifetime of the metastable 4F3/2 state, the luminescence linewidth, probability, and cross-section of the most intensive transition are determined. From the radiative decay time of the 4F3/2 metastable state of dilute crystals (low x) and the transition probability of the resonance channel 4I9/2 4I3/2 x = 1, the parameter of spectroscopic quality X is calculated. Using X, intermanifold luminescence bracnching ratios are determined. Stimulated emission of K5Bi1−xNdx(MoO4)4 crystals with x = 0.1 is excited in the pulse regime, using optical broad-band pumping by Xe flash-tube, and of “self-activated” crystals with x = 1, using laser excitation by a Raman laser, operating at λ = 0.745 and 0.805 μm.
[Russian text Ignored.]
51 citations
TL;DR: In this article, the fully resolved spectrum of the Q-branch of the ν2 band in acetylene has been obtained by cw CARS spectroscopy with a resolution of 40 MHz.
44 citations
TL;DR: In this article, color center lasers in different alkali halide crystals were found to oscilate in one primary and one or two hole burning modes without using frequency selecting elements.
TL;DR: In this paper, the Raman linewidth of the 914 cm−1 line of the ferroelectric phase of KH2PO4 was measured as a function of temperature and a correlation was found between the Ramannan linwidth, the spotaneous polarization and the proton spin-lattice relaxation time.
TL;DR: In this article, it was shown that the spatial coherence radius of the field of a singlemode laser beam traveling in a turbulent atmosphere exceeds that of plane and spherical waves, and that this excess is greatest in the case of strong fluctuations of the beam intensity.
Abstract: It is shown theoretically that the spatial coherence radius of the field of a single-mode laser beam traveling in a turbulent atmosphere exceeds the coherence radius of plane and spherical waves. It is established that this excess is greatest in the case of strong fluctuations of the beam intensity. A study is made of the influence of a partial coherence of a light source on the coherence radius of the beam field. It is demonstrated that the radius of the spatial coherence of a beam becomes independent of the diffraction size and coherence of the source when the random phase shifts increase sufficiently over a distance equal to the radius of the first Fresnel zone. A solution is obtained of the problem of turbulence-induced spreading of the image of a partly coherent laser source formed in the focal plane of the receiver lens.
TL;DR: In this article, a weak secondary signal is partially absorbed in a ferromagnetic microwave limiter that is saturated by a strong primary signal; the absorption is greatest when the two signals are close in frequency, and the width of this absorption is determined here, and is found to be proportional to the spin wave linewidth and to the square root of the excess power in the primary signal.
Abstract: A weak secondary signal is partially absorbed in a ferromagnetic microwave limiter that is saturated by a strong primary signal; the absorption is greatest when the two signals are close in frequency. The width of this absorption is determined here, and is found to be proportional to the spin wave linewidth and to the square root of the excess power in the primary signal. The theory of this effect is presented and is found to agree well with experiment.
TL;DR: In this article, the results for the fluorescent spectrum arising in the cooperative interaction of a population of two-level atoms driven by resonant laser radiation with the electromagnetic field are presented.
Abstract: Analytic results for the fluorescent spectrum arising in the cooperative interaction of a population of two-level atoms, driven by resonant laser radiation with the electromagnetic field are presented. The bistability and hysteresis characterising single-time atomic averages are evidenced explicitly as this spectrum is viewed throughout a hysteresis cycle. In the region of bistability full support is given to the designation of a cooperative and a non-cooperative branch. Spectral features reveal linewidths associated with cooperative and non-cooperative atomic decay rates respectively. A dominant feature is strong coherent scattering throughout the cooperative region, fully supporting an identification of this problem with super-radiant phenomena. Linewidth narrowing is predicted in the vicinity of both instabilities.
TL;DR: In this article, a 1 MW nitrogen laser was used to achieve a peak power output of 100 kW in the visible at a linewidth as low as 60 MHz using a cw dye laser oscillator followed by three single pass dye amplifier stages.
TL;DR: The hole burning method has been employed for measuring the homogeneous contours of the purely electronic line in the luminescence of the H 2 -tetra-4-tert-butylphtalocyanine molecule in solid tetradecane as mentioned in this paper.
TL;DR: In this article, the authors describe photon autocorrelation studies of both the depolarized and polarized components of light scattered from the critical binary mixture methanol-cyclohexane, carried out to kxi approx.
Abstract: We describe photon autocorrelation studies of both the depolarized and polarized components of light scattered from the critical binary mixture methanol-cyclohexane, carried out to kxi approx. = 80, in an effort to differentiate between the Rayleigh linewidth predictions of the mode theories and the dynamic droplet model, and to assess the validity of our treatment of the autocorrelation function of light which undergoes double scattering from a critical fluid. (Here k is the scattering wave number and xi the Orstein-Zernike correlation length.) We achieved sample temperature control of +- 15 ..mu../sup 0/C for periods of 24 hours and reduced sample temperature gradients to approx. 1.more » Despite the large multiple-scattered component in the light scattered from the fluid in the nonhydrodynamic regime, the Rayleigh linewidth is affected only slightly. We show how to estimate the amount of multiple scattered light from depolarization-ratio measurements, and make qualitative assessments of the modifications of the Rayleigh linewidth due to higher-order scattering. Despite the small effect of multiple scattering upon the Rayleigh linewidth at large values of kxi, the uncertainty introduced is enough to obscure the differences between the fits of the mode theories and the dynamic droplet model to our experimental results.« less
TL;DR: In this paper, the quantum yield of electronically excited atomic oxygen produced from ozone photolysis was measured at 298 K from wavelengths of 293.0 to 316.5 nm, with a sharp decrease centered at 308 nm and a diminution to less than one tenth of the constant value by 313.5nm.
Abstract: The quantum yield of electronically excited atomic oxygen produced from ozone photolysis was measured at 298 K from wavelengths of 293.0 to 316.5 nm. The reaction of the atomic oxygen with N2O to form excited NO2 was used to monitor the O production; a frequency-doubled flashlamp-pumped dye laser which provided tunable ultraviolet in the desired spectral region with 0.1-nm linewidth served as the photolysis source. The atomic oxygen quantum yield was found to be constant below 300 nm, with a sharp decrease centered at 308 nm and a diminution to less than one tenth of the constant value by 313.5 nm.
TL;DR: In this paper, the authors investigated the temperature dependence of the Na + -2p-photoemission linewidth from thin films of NaCl and found a large contribution due to coupling to lattice vibrations.
TL;DR: In this paper, a tunable, continuous-wave, frequency-doubled, rhodamine 6G dye laser has been developed using an ADA crystal placed in an astigmatic and coma compensated cavity.
TL;DR: In this paper, a new value for the quadrupole moment has been derived: Q = (105±2) mbarn, which is the largest value known to date.
TL;DR: In this article, the X-ray photoelectron spectrum of atomic Kr in the M 2,3 (3 p ) region has been calculated from first principles using diagrammatic many-body theory.
TL;DR: In this paper, high power stimulated radiation was obtained in three fluorides of rare gases by exciting a high pressure mixture of He+R+SF6 (R is argon, krypton, xenon) by a pulse electric discharge (mixture pressure ranged from 1 to 10 atm).
Abstract: High-power stimulated radiation was obtained in three fluorides of rare gases by exciting a high pressure mixture of He+R+SF6 (R is argon, krypton, xenon) by a pulse electric discharge (mixture pressure ranged from 1 to 10 atm). The ArF laser superradiance spectrum of about 15 A total width with the centre at λ=1932 A is given. The ArF laser power wasP≈104 W. The KrF laser generated 2 ns pulses of about 2.5 MW power at λ=2486 A with a linewidth Δλ≈10 A. This laser efficiency in relation to the stored energy of an accumulator is about 0.2%. In the XeF laserP=200 to 300 kW, τ=3 to 3.5 ns, λ=3511, 3531 A. High density of superradiance power is observed. The prospects of increase of mean power of excimer lasers are discussed.
TL;DR: In this paper, a tiltable Ge etalon has been introduced into the TEA resonator to reduce the linewidth mismatch between the emission lines of a CO 2 -TEA laser and the absorption lines of low-pressure FIR gain medium.
Abstract: To reduce the linewidth mismatch between the emission lines of a CO 2 -TEA laser and the absorption lines of a low-pressure FIR gain medium a tiltable Ge etalon has been introduced into the TEA resonator. The resulting spectral compression and tunability increase the energy conversion efficiency in a TEA laser pumped CH 3 OH laser by as much as a factor of 37 and has led to the observation of 14 new FIR laser lines.
TL;DR: In this article, a dye laser and its Stokes components in hydrogen gas are used to cover the total spectral range with powers between 1000 and 9 MW, and a successful attempt was made to reduce it to 0.02 cm−1 without any change in the output power.
Abstract: Efficient generation of high peak radiation has been achieved in the 0.72–7.7 μm region. A dye laser and its Stokes components in hydrogen gas are used to cover the total spectral range with powers between 1000 and 9 MW. The linewidth of the dye laser is 0.07 cm−1. A successful attempt was made to reduce it to 0.02 cm−1 without any change in the output power.
TL;DR: In this paper, the rate constants of proton transfer in NH4HSO4, NH4 HSO4 + HCl and H2SO4 aqueous solutions were estimated by resolving the observed bands into several components with a Voigt profile.
Abstract: The ν1 Raman linewidths of SO in NH4HSO4, NH4HSO4 + HCl and H2SO4 aqueous solutions were estimated by resolving the observed bands into several components with a Voigt profile. From their concentration dependence, the rate constants of proton transfer were estimated to be 4.5 × 1011 M−1s−1 consistently for the three kinds of acidic solutions.