5 research outputs found
Coherently averaged dual-comb spectroscopy with a low-noise and high-power free-running gigahertz dual-comb laser
We present a new type of dual optical frequency comb source capable of
scaling applications to high measurement speeds while combining high average
power, ultra-low noise operation, and a compact setup. Our approach is based on
a diode-pumped solid-state laser cavity which includes an intracavity biprism
operated at Brewster angle to generate two spatially-separated modes with
highly correlated properties. The 15-cm-long cavity uses an Yb:CALGO crystal
and a SESAM as an end mirror to generate more than 3 W average power per comb,
below 80 fs pulse duration, a repetition rate of 1.03 GHz, and a continuously
tunable repetition rate difference up to 27 kHz. We carefully investigate the
coherence properties of the dual-comb by a series of heterodyne measurements,
revealing several important features: (1) ultra-low jitter on the uncorrelated
part of the timing noise; (2) the radio frequency comb lines of the
interferograms are fully resolved in free-running operation; (3) we validate
that through a simple measurement of the interferograms we can determine the
fluctuations of the phase of all the radio frequency comb lines; (4) this phase
information is used in a post-processing routine to perform coherently averaged
dual-comb spectroscopy of acetylene (C2H2) over long timescales. Our results
represent a powerful and general approach to dual-comb applications by
combining low noise and high power operation directly from a highly compact
laser oscillator
Rapid-scan nonlinear time-resolved spectroscopy over arbitrary delay intervals
Femtosecond dual-comb lasers have revolutionized linear Fourier-domain
spectroscopy by offering a rapid motion-free, precise and accurate measurement
mode with easy registration of the combs beat note in the RF domain. Extensions
of this technique found already application for nonlinear time-resolved
spectroscopy within the energy limit available from sources operating at the
full oscillator repetition rate. Here, we present a technique based on time
filtering of femtosecond frequency combs by pulse gating in a laser amplifier.
This gives the required boost to the pulse energy and provides the flexibility
to engineer pairs of arbitrarily delayed wavelength-tunable pulses for
pump-probe techniques. Using a dual-channel millijoule amplifier, we
demonstrate programmable generation of both extremely short, fs, and extremely
long (>ns) interpulse delays. A predetermined arbitrarily chosen interpulse
delay can be directly realized in each successive amplifier shot, eliminating
the massive waiting time required to alter the delay setting by means of an
optomechanical line or an asynchronous scan of two free-running oscillators. We
confirm the versatility of this delay generation method by measuring chi^(2)
cross-correlation and chi^(3) multicomponent population recovery kinetics
Dual-comb laser enables broadband detection of optical anisotropies
The measurement of optical anisotropies is widely employed in many application fields, such as material and biomedical sciences. Such spectro- scopic method monitors the polarization state alterations after the interaction be- tween matter and different states of polarized light. Here, we use a newly developed single-cavity dual-comb laser to demonstrate proof-of-principle polarization-resolved measurements. We detect the signals resulting from the heterodyne mixing of the two combs. The interferograms encode the information about the polarimetric prop- erties of samples at kHz rate. Our results complement earlier work with similar single-cavity dual-comb lasers demonstrating pump-probe sampling, and pave the way for a new platform for multimodal sensing
Dual-comb laser enables broadband detection of optical anisotropies
The measurement of optical anisotropies is widely employed in many application fields, such as material and biomedical sciences. Such spectroscopic method monitors the polarization state alterations after the interaction between matter and different states of polarized light. Here, we use a newly developed single-cavity dual-comb laser to demonstrate proof-of-principle polarization-resolved measurements. We detect the signals resulting from the heterodyne mixing of the two combs. The interferograms encode the information about the polarimetric properties of samples at kHz rate. Our results complement earlier work with similar single-cavity dual-comb lasers demonstrating pump-probe sampling, and pave the way for a new platform for multimodal sensing
Rapid-Scan Nonlinear Time-Resolved Spectroscopy over Arbitrary Delay Intervals
Femtosecond dual-comb lasers have revolutionized linear Fourier-domain spectroscopy by offering a rapid motion-free, precise, and accurate measurement mode with easy registration of the combs beat note in the radio frequency domain. Extensions of this technique already found application for nonlinear time-resolved spectroscopy within the energy limit available from sources operating at the full oscillator repetition rate. Here, we present a technique based on time filtering of femtosecond frequency combs by pulse gating in a laser amplifier. This gives the required boost to the pulse energy and provides the flexibility to engineer pairs of arbitrarily delayed wavelength-tunable pulses for pump–probe techniques. Using a dual-channel millijoule amplifier, we demonstrate programmable generation of both extremely short, fs, and extremely long (>ns) interpulse delays. A predetermined arbitrarily chosen interpulse delay can be directly realized in each successive amplifier shot, eliminating the massive waiting time required to alter the delay setting by means of an optomechanical line or an asynchronous scan of 2 free-running oscillators. We confirm the versatility of this delay generation method by measuring χ(²) cross-correlation and χ(³) multicomponent population recovery kinetics.ISSN:2097-0331ISSN:2765-879