Related papers: Terahertz multi-heterodyne spectroscopy using lase…
The sensitivity of molecular fingerprinting is dramatically improved when placing the absorbing sample in a high-finesse optical cavity, thanks to the large increase of the effective path-length. As demonstrated recently, when the…
Optical frequency-comb-based-high-resolution spectrometers offer enormous potential for spectroscopic applications. Although various implementations have been demonstrated, the lack of suitable mid-infrared comb sources has impeded…
Infrared spectroscopy is a powerful tool for basic and applied science. The molecular spectral fingerprints in the 3 um to 20 um region provide a means to uniquely identify molecular structure for fundamental spectroscopy, atmospheric…
We present a 2-\mum frequency comb based on a reliable mode-locked Er:fiber laser with 100 MHz repetition rate. After shifting the spectrum of the amplified Er:fiber comb to longer wavelengths, a single-clad Tm/Ho:fiber is used as a…
Laser frequency combs are coherent light sources that emit a broad spectrum consisting of discrete, evenly spaced narrow lines, each having an absolute frequency measurable within the accuracy of an atomic clock. Their development, a decade…
Molecular spectroscopy in the mid-infrared portion of the electromagnetic spectrum (3--25 um) has been a cornerstone interdisciplinary analytical technique widely adapted across the biological, chemical, and physical sciences. Applications…
Terahertz (THz) frequency combs (TFCs) are promising for numerous applications in spectroscopy, metrology, sensing, and wireless communications. However, the practical applications of TFCs have been hindered thus far by the need for…
We perform heterodyne spectroscopy at 1.56 micron with a tunable laser and thermal radiation from the Sun. The laser tuning is calibrated with a frequency comb, providing a simple spectrometer with absolute frequency tracebility and…
Optical frequency combs enable coherent data transmission on hundreds of wavelength channels and have the potential to revolutionize terabit communications. Generation of Kerr combs in nonlinear integrated microcavities represents a…
While mid-infrared optical frequency combs have been widely utilized in areas such as trace gas sensing, chemical kinetics, and combustion science, the relatively low power per comb tooth has limited acquisition times and sensitivities. We…
The mid-infrared (mid-IR) regime (typically the wavelength regime of $\lambda \sim 2.5-20 \ \mathrm{\mu m}$) is an important spectral range for spectroscopy as many molecules have their fundamental rotational-vibrational absorption in this…
We demonstrate simple optical frequency combs based on semiconductor quantum well laser diodes. The frequency comb spectrum can be tailored by choice of material properties and quantum-well widths, providing spectral flexibility. Finally,…
Optical frequency combs based on mode-locked lasers have revolutionised the field of metrology and precision spectroscopy by providing precisely calibrated optical frequencies and coherent pulse trains. Amplification of the pulsed output…
A novel study on harmonic frequency combs emitted by Quantum Cascade Lasers (QCLs) is here presented, demonstrating the presence of intensity correlations between twin modes characterising the emission spectra. These originate from a…
The optical frequency comb has made a significant impact in precision spectroscopy and on our ability to probe atomic, molecular and, recently, nuclear transitions to further our understanding of their fundamental properties and how their…
Quantum cascade lasers are compact sources capable of generating frequency combs. Yet key characteristics - such as optical bandwidth and power-per-mode distribution - have to be improved for better addressing spectroscopy applications.…
We demonstrate a 0.95 GHz repetition rate fully stabilized Yb:fiber frequency comb without optical amplification. Benefitted from the high mode power and high coherence, this comb achieved 35 dB to 42 dB signal to noise ratio on the direct…
Dissipative Kerr-microresonator soliton combs (hereafter called soliton combs) are promising to realize chip scale integration of full soliton comb systems providing high precision, broad spectral coverage and a coherent link to the…
For the growing demand of frequency combs in mid-infrared (mid-IR), known as the "molecular fingerprint" region of the spectrum [1], down conversion of near-IR frequency combs through half- harmonic generation offers numerous benefits…
We introduce a new cascaded four-wave mixing technique which scales up the bandwidth of frequency combs generated by phase modulation of a continuous wave laser while simultaneously enhancing the spectral flatness. As a result we…