Interference phenomena in coherent active spectroscopy of light scattering and absorption: holographic multidimensional spectroscopy

Abstract

We calculate the spectrum of glueball masses in non-supersymmetric Yang-Mills theory in three and four dimensions, based on a conjectured duality between supergravity and large N gauge theories. The glueball masses are obtained by solving supergravity wave equations in a black hole geometry. We find that the mass ratios are in good numerical agreement with the available lattice data. We also compute the leading (g 2 Y M N) −1 corrections to the glueball masses, by taking into account stringy corrections to the supergravity action and to the black hole metric. We find that the corrections to the masses are negative and of order (g 2 Y M N) −3/2 . Thus for a fixed ultraviolet cutoff the masses decrease as we decrease the 't Hooft coupling, in accordance with our expectation about the continuum limit of the gauge theories.

Impact of the dipole contribution on the terahertz emission of air-based plasma induced by tightly focused femtosecond laser pulses

“…At the same time, the nonlinear optical signal can be presented in the form of the sum of dipole and quadrupole contributions [16,17] if the nonlinear optical processes lead to the generation of the electromagnetic waves at the same frequency. Attempts to separate these waves date back to the early study of nonlinear optics [18,19].…”

Quantum resolution limit via coherent polarization Raman spectroscopy

“…In a widely used two-color CARS setting, the probe is delivered in the same beam as the first driver, with ω 1 ¼ ω 3 , I 1 ¼ I 3 , and e 1 ¼ e 3 , giving rise to an anti-Stokes readout signal at ω a ¼ 2ω 1 À ω 2 . With the polarization analyzer in the anti-Stokes detection path set to transmit the field polarized along e a , the overall CARS signal reaching the detector is [36][37][38][39]45]…”

“…Although nonresonantbackground suppression by one or two orders of magnitude is adequate for many polarization CARS studies, [36][37][38][39][46][47][48] background suppression by four to five orders of magnitude is possible via fine, carefully controlled polarization adjustments. [38,[49][50][51] Because the depolarization ratios ρ α are often measurably distinct even for the Raman modes with close frequencies, [39,[50][51][52][53][54][55][56][57] polarization methods in coherent Raman spectroscopy provide a powerful resource that helps resolve closely spaced and overlapping spectral lines within the vibrational Raman bands of a vast class of atomic and molecular systems. [38,39,[46][47][48][49][50][51][52][53][54][55][56][57][58] As one example, when applied to the 1000-cm À1 Raman band of pure liquid styrene, polarization CARS spectroscopy reveals two overlapping spectral lines representing two distinct Raman-active modes with equal central frequencies, Ω R1 ¼ Ω R2 ≈ 1000 cm À1 , but different depolarization ratios and linewidths.…”

“…In experiments, the degree of nonresonant-background suppression attainable in polarization CARS is limited by the residual depolarization of laser beams, as well as the optical-Kerreffect-induced birefringence. Although nonresonantbackground suppression by one or two orders of magnitude is adequate for many polarization CARS studies, [36][37][38][39][46][47][48] background suppression by four to five orders of magnitude is possible via fine, carefully controlled polarization adjustments. [38,[49][50][51] Because the depolarization ratios ρ α are often measurably distinct even for the Raman modes with close frequencies, [39,[50][51][52][53][54][55][56][57] polarization methods in coherent Raman spectroscopy provide a powerful resource that helps resolve closely spaced and overlapping spectral lines within the vibrational Raman bands of a vast class of atomic and molecular systems.…”

“…[53] Numerous examples of Raman-active modes of atoms and molecules with close frequencies but measurably different ρ α are found in the extensive literature (e.g., refs. [38,39,[45][46][47][48][49][50][51][52][53][54][55][56][57][58]). As one of the most striking insights from early-era nonlinear optics, the method was deemed capable of providing an unlimited spectral resolution, [36][37][38][39] suggesting means to resolve closely spaced and overlapping spectral lines no matter how small the spectral separation between these lines is.…”