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The ability to transfer entanglement over large distance is a main requirement for quantum networks. Another fundamental ingredient is the storage of such a quantum state in a quantum memory. To this end a useful resource is a photon pair for which one photon is resonant with the memory while its partner is at a low-loss telecommunication wavelength. We recently presented a photon pair source, compatible...
Accurate molecular spectroscopy in the mid-infrared (mid-IR) region allows precision measurements with applications in fundamental physics. We present our on-going work towards measuring absolute vibrational frequencies of various polyatomic species — in particular methanol — around 10 μm, at an unprecedented level of accuracy, using a both ultra-stable and widely tuneable near-infrared frequency...
We present, for the first time, the results regarding the production of refractive index (RI) sensors, through the acousto-optic effect in tilted fiber Bragg gratings (TFBGs). The RI is analysed in detail when acoustic waves are turned on using saccharose solutions with different RI from 1.3327 to 1.4249.
Silica/air large-pitch photonic crystal fibers, known simply as large-pitch fibers (LPFs) due to their hole-to-hole spacing 10 times larger than the wavelength, performing mode-field diameters (MFDs) about 50 μm along with nearly diffraction-limited output beam quality provide a versatile platform for realizing compact and stable multi-kW average power and multi-mJ pulse energy ultrashort pulse fiber...
Electro-optical combs generated from continuous-wave sources through amplitude and phase modulations have the potential to generate picosecond pulses with multi-GHz tunable repetition rates. They find applications in polarized Gamma ray production [1], imaging and picosecond acoustics. However, the development of such combs is mainly carried out with 1.5 μm laser sources [2, 3]. Only few developments...
Optical frequency combs (OFCs) have led to an impressive number of achievements, including multi-heterodyne spectroscopy [1]. Mode-locked OFCs have been widely used due to their exceptional spectral bandwidth, but they usually require sophisticated locking methods to control the free spectral range (FSR) and the absolute frequency of the comb. A promising alternative is provided by electro-optic OFCs,...
Electro-optical combs generated from continuous-wave sources through amplitude and phase modulations have the potential to generate picosecond pulses with multi-GHz tunable repetition rates. They find applications in polarized Gamma ray production [1], imaging and picosecond acoustics. However, the development of such combs is mainly carried out with 1.5 μm laser sources [1, 2]. Only few developments...
The QCL comb was first unveiled in the mid-IR in 2014, proven a true comb by a technique called beatnote spectroscopy[1]. The temporal field profile of such a comb is of great interest, but unfortunately such a technique does not capture phase information. We already know the inherently short upper-state lifetime of QCLs inhibits transform limited pulses[2] as in conventional mode-locked laser combs,...
The canonical example of coherent interaction between oscillators is a system of coupled pendulums — where due to the coupling, energy is transferred slowly from one oscillator to the other and back at a beat frequency that reflects the coupling strength. A system of coupled pendulums is an idealization of coherent transfer of energy, that cannot be directly observed in steady-state — a real system...
The potential of Optical Frequency Combs (OFC) as wide bandwidth, stable, coherent, multimode sources is widely recognized and has applications in various fields, such as metrology, spectroscopy, optical communications or biomedicine. The dual optical frequency comb approach relies on the use of a second local oscillator (LO) comb with slightly different repetition frequency. This LO is then heterodyned...
Large arm length imbalance fibre-based interferometers have shown great potential for laser frequency stabilization and control, with frequency noise power spectral density close to the 10−1 Hz/Hz1/2 level [1]. In order to understand the performance of such frequency stabilization systems, it is important to distinguish the intrinsic noise of the frequency reference, which is ultimately limited by...
Heralded single-photon sources are a standard experimental tool for studying quantum optics and quantum information in few-photon systems. These sources use spontaneous parametric wave mixing to probabilistically emit pairs of photons. One photon of the pair, the heralding photon, is detected to indicate the presence of the other. In theory, the maximal probability of emitting a single pair of photons...
Gravitational Wave (GW) is very small temporal variation of space distortion which is caused from the change of enormous mass such as inspiral and merger of black hole binaries, explosion of supernovae, and the inflation in the early universe. In order to detect GW directly, long-baseline laser interferometers have been developed by many countries and, at long last, the first direct detection of GW...
Spin plays a fundamental role in the electronic structure of matter, from single atoms and molecules through to condensed matter. However, spin dynamics and the spin response of electrons to ultra-short, strong laser pulses has remained largely unexplored until today. In 2011 and 2013, pioneering theoretical work [1, 2] extended the fundamental PPT theory [3] to treat ionization of p+ and p” electrons...
A good and efficient control of the focus point of a laser beam is essential in many fields such as laser processing and wielding, and confocal microscopy. The most common way of changing the focus position of a beam is to use lenses, usually in the form of a telescope. However, inertia imposes a limit to the frequency at which one can modulate the position of a mechanical element. Other techniques,...
High-power fibre laser systems generally rely on microstructured fibres combining an effective single-mode emission and a very large-mode area (V-LMA, Dcore > 50μm). Most of time, the targeted applications (one can cite for instance the frequency conversion [1]) require a crucial control of the state of polarization (SOP) of the emitted beam, leading to the development of polarization-maintaining...
Optical frequency combs from ultrafast lasers have revolutionized the field of optical metrology and photonics. However, today's commercial frequency combs are still based on complex and expensive ultrafast laser systems, which prevent applications for cost-sensitive areas. Among emerging technologies, modelocked semiconductor lasers are highly promising for future low-cost high-volume production...
Extended-cavity quantum cascade lasers (EC-QCLs) enable mode-hope-free frequency sweeps in the mid-infrared region over ranges in excess of 100 cm−1, at speeds up to 1 THz/s and with a 100-mW optical power level. This makes them ideally suited for broadband absorption spectroscopy and for the simultaneous detection of multiple gases. On the other hand, their use for precision spectroscopy has been...
One of the most essential building blocks in modem electronics is the flip-flop. A flip-flop operates bi-stably between two states, remaining at a given output level (high or low level) until a specific input control signal changes. For many years, photonics has attempted to build all-optical flip-flops [1-3]; however, the success of these approaches has usually been limited by the dependence of the...
Wavelength tuneable lasers for 40G and 100G coherent optical communications systems need to meet stringent requirements on narrow linewidth emission across the entire tuning range, with typical values of 300–500 kHz required in commercial systems. Higher capacities can be achieved in next generation systems by employing higher order modulation formats such as 16QAM or 64QAM. However, such systems...
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