We stabilized the carrier-envelope phase of pulses emitted by a femtosecond mode-locked laser using powerful tools frequency-domain stabilization. confirmed control pulse-to-pulse temporal cross correlation. This stabilization locks absolute frequencies laser, which we used to perform optical frequency measurements that were directly referenced stable microwave clock.

We demonstrate a great simplification in the long-standing problem of measuring optical frequencies terms cesium primary standard. An air-silica microstructure fiber broadens frequency comb femtosecond laser to span octave from 1064 532 nm, enabling us measure 282 THz an iodine-stabilized Nd:YAG directly microwave that controls spacing. Additional measurements established at 633 and 778 nm using same confirm accepted uncertainties for these standards.

Recently there has been a remarkable synergy between the technologies of precision laser stabilization and mode-locked ultrafast lasers. This resulted in control frequency spectrum produced by lasers, which consists regular comb sharp lines. Thus such controlled is ``femtosecond optical generator.'' For sufficiently broad comb, it possible to determine absolute frequencies all ability revolutionized metrology synthesis. It also served as basis for recent demonstrations atomic clocks that...

The motions of electrons in solids may be highly correlated by strong, long-range Coulomb interactions. Correlated electron-hole pairs (excitons) are accessed spectroscopically through their allowed single-quantum transitions, but higher-order correlations that strongly influence electronic and optical properties have been far more elusive to study. Here we report direct observation bound exciton (biexcitons) provide incisive signatures four-body among holes gallium arsenide (GaAs) quantum...

We outline two general theoretical techniques to simulate polariton quantum dynamics and optical spectra under the collective coupling regimes described by a Holstein–Tavis–Cummings (HTC) model Hamiltonian. The first one takes advantage of sparsity HTC Hamiltonian, which allows reduce cost acting Hamiltonian onto state vector linear order number states, instead quadratic order. second is applying well-known Chebyshev series expansion approach for propagation in system; this us use much...

The synthesis of optical frequencies from the primary cesium microwave standard has traditionally been a difficult problem due to large disparity in frequency. Recently this field dramatically advanced by introduction and use mode-locked lasers. This application lasers particularly aided ability generate spectra that span an octave. review article describes how are used for frequency gives recent results obtained using them.

We show, experimentally and numerically, that Ti:sapphire mode-locked lasers can operate in a regime which they intermittently produce exploding solitons. This happens when the laser operates near critical point. Explosions happen spontaneously, but external perturbations trigger them. In stable operation, all explosions have similar features, are not identical. The characteristics of depend on intracavity dispersion.

We observe polarization-locked vector solitons in a mode-locked fiber laser. Temporal have components along both birefringent axes. Despite different phase velocities due to linear birefringence, the relative of is locked at $\ifmmode\pm\else\textpm\fi{}\ensuremath{\pi}/2$. The value $\ifmmode\pm\else\textpm\fi{}\ensuremath{\pi}/2$ and component magnitudes agree with simple analysis Kerr nonlinearity. These fragile phase-locked been subject much theoretical conjecture, but previously eluded...

New methods have recently been developed to measure the carrier-envelope phase evolution of ultrashort optical pulses. These utilize a powerful combination time-domain and frequency-domain techniques. The resulting ability stabilize pulse train emitted by mode-locked laser means that absolute frequencies in spectrum can be determined, which has had an immediate impact on frequency metrology clocks. In time domain, this establishes basis for controlling tailoring electric field pulses, will...

Multidimensional Coherent Optical Photocurrent Spectroscopy (MD-COPS) is implemented using unstabilized interferometers.Photocurrent from a semiconductor sample generated sequence of four excitation pulses in collinear geometry.Each pulse tagged with unique radio frequency through acousto-optical modulation ; the Four-Wave Mixing (FWM) signal then selected domain.The interference an auxiliary continuous wave laser, which sent same interferometers as pulses, used to synthesize reference...

Techniques developed decades ago for nuclear magnetic resonance and now adapted the IR, visible, UV regions of spectrum are enabling new insights into chemical kinetics solid-state physics.

The JILA multidimensional optical nonlinear spectrometer (JILA-MONSTR) is a robust, ultrastable platform consisting of nested and folded Michelson interferometers that can be actively phase stabilized. This generates square identical laser pulses adjusted to have arbitrary time delay between them while maintaining stability. JILA-MONSTR provides output for excitation materials phase-stabilized reference heterodyne detection the induced signal. arrangement ideal performing coherent...

The degenerate-four-wave-mixing response of excitons in GaAs quantum wells is modeled using the optical Bloch equations including exciton-exciton interactions. results display a strong dependence on polarization excitation pulses. model predicts intensity and dependences time-integrated signal characteristic temporal features time-resolved excellent agreement with observations.

We study many-body interactions between excitons in semiconductors by applying the powerful technique of optical two-dimensional Fourier transform spectroscopy. A spectrum correlates phase (frequency) evolution nonlinear polarization field during initial and final detection period. single can identify couplings resonances, separate quantum mechanical pathways, distinguish among microscopic interactions.

A new low photon energy regime of angle-resolved photoemission spectroscopy is accessed with lasers and used to study the high T(C) superconductor Bi2Sr2CaCu2O(8+delta). The increases bulk sensitivity, reduces background, improves resolution. With this we observe spectral peaks which are sharp on scale their binding energy--the clearest evidence yet for quasiparticles in normal state. Crucial aspects data such as dispersion, superconducting gaps, bosonic coupling kink found be robust a...

We derive an analytical form for resonance lineshapes in two-dimensional (2D) Fourier transform spectroscopy. Our starting point is the solution of optical Bloch equations a two-level system 2D time domain. Application projection-slice theorem transforms reveals diagonal and cross-diagonal slices frequency data arbitrary inhomogeneity. The results are applied quantitative measurements homogeneous inhomogeneous broadening multiple resonances experimental data.

Dual laser frequency combs can rapidly measure high-resolution linear absorption spectra. However, one-dimensional techniques cannot distinguish the sources of resonances in a mixture different analytes, nor they separate inhomogeneous and homogeneous broadening. Here, we overcame these limitations by acquiring multidimensional nonlinear coherent spectra with combs. We experimentally differentiated assigned Doppler-broadened features two naturally occurring isotopes rubidium atoms (87Rb...

We present experimental coherent two-dimensional Fourier-transform spectra of Wannier exciton resonances in semiconductor quantum wells generated by a pulse sequence that isolates two-quantum coherences. By measuring the real part signals, we determine are dominated coherences due to mean-field many-body interactions, rather than bound biexcitons. Simulations performed using dynamics controlled truncation agree with experiments.

We report the observation of double-quantum coherence signals in a gas potassium atoms at twice frequency one-quantum coherences. Since single atom does not have state corresponding energy, this must be attributed to collective resonance involving multiple atoms. These resonances are induced by weak interatomic dipole-dipole interactions, which means that cannot treated isolation, even low density ${10}^{12}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$.

In our previous work [Mondal et al., J. Chem. Phys. 162, 014114 (2025)], we developed several efficient computational approaches to simulate exciton–polariton dynamics described by the Holstein–Tavis–Cummings (HTC) Hamiltonian under collective coupling regime. Here, incorporated these strategies into previously Lindblad-partially linearized density matrix (L-PLDM) approach for simulating 2D electronic spectroscopy (2DES) of particular, apply quantum propagation scheme in Paper I both forward...

We demonstrate quantum interference control of injected photocurrents in a semiconductor using the phase stabilized pulse train from mode-locked Ti:sapphire laser. Measurement comb offset frequency via this technique results signal-to-noise ratio 40 dB (10 Hz resolution bandwidth), enabling solid-state detection carrier-envelope shifts oscillator.