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Compact monolithic single-mode red emitting diode lasers are still not readily available for many wavelengths in the visible spectrum. Strontium lattice and Calcium clocks are some of the most widely investigated optical clocks worldwide and the pertinent transitions wavelengths required are in the red and blue wavelength spectral region. The current state of the art in laser technology employs external...
Traditional lasers are composed by three basic elements: an amplifying medium, an external pumping setup, and an optical cavity that confines and shapes the emitted light in well-determined modes and directions. However, several modern approaches are extending this traditional laser paradigm into new avenues. Cavity-free stimulated emission of radiation has been widely studied in random lasers (RLs)...
Stimulated Raman scattering presents one of important trends in nonlinear optics enabling to generate Stokes-shifted radiation at frequencies that are not readily available from solid state lasers. This method is suitable also because the phase matching fulfilment isn't required. To get stable and efficient Raman generation of picosecond and even femtosecond ultra-short Stokes pulses, the method of...
Detection of chemical species using differential absorption lidar is a topic of growing interest for safety in petrochemical facilities, outdoor air quality measurements, greenhouse gases monitoring from space, and standoff detection of toxic chemical plumes. In such a lidar the optical source must combine a high energy (> 10 mJ for range-resolved detection), a wide and arbitrary wavelength tunability,...
The negatively charged nitrogen-vacancy (NV) color center in diamond has been widely investigated for applications spanning from quantum information processing to nanoscale sensing [1]. Central to its utility is its combination of a long-lived electronic spin state with optical initialization and readout. However, the fidelity of room-temperature NV spin readout is limited, due to the low rate of...
Although shaping of fields around nanostructures is widely studied in plasmonics, the influence of the field inside the nanostructures is often overlooked. The linear field distribution inside the structure taken to the third power causes third-harmonic generation, a nonlinear optical response of matter. We demonstrate how this simple fact can be used to shape complex fields around a single particle...
Distributed Raman amplification is an attractive way to improve the OSNR in optical transmission systems. However, this requires profound system knowledge to profit from these potential benefits. Especially in the case of co-directional pumped Raman amplifiers the evolution of the signal powers over the propagation distance is of interest in order to avoid signal distortions. Within the design process...
Dual order bidirectional Raman amplification are preferred over first order counterpart due to their lower signal power variation (SPV) and consequently superior optical signal to noise ratio (OSNR) performance [1]. These benefits are counteracted by the disadvantage of relative intensity noise (RIN) transfer from forward pumps to signal [1, 2]. In this work, we demonstrate a forward pumping scheme...
Technology for self-driving vehicles is currently under heavy development. Reliable autonomous driving requires precise information from different sensors, in order to establish a realistic and accurate model of the vehicle's environment. Time-of-Flight (ToF) sensors can contribute valuable information to such a vehicle's sensor network [1]. The influence of weather effects, in particular rain droplets,...
The capacity of Erbium-doped amplifiers (EDFA) systems is rapidly being approached, and thus research is increasing in alternative technologies which can deliver broader gain spectrum than EDFAs to increase system capacity [1]. Fiber Raman Amplifiers (FRAs) provide gain in any spectral region provided that a suitable pump and fiber are available. Distributed amplifiers using the transmission fibre...
Hollow-core photonic crystal fibers (HC-PCF) opened new perspectives towards multi-octave comb generation and waveform synthesis using stimulated Raman scattering (SRS) generation in gases introduced in its core [1, 2]. In the transient regime of SRS [3], a short pump pulse combined to a high gain can amplify a few spatial-temporal modes (STM) from the quantum noise. It is even possible to have only...
Nitrogen vacancy (NV) centres are a type of defect in diamond that exhibit a number of interesting properties. NV centres can be optically excited around 450–650 nm and emit fluorescence at around 550–800 nm [1]. The optical excitation also spin polarises the negatively charged NV centres, permitting optical detection of magnetic resonance [2]. This allows nanotesla scale sensitive magnetometry to...
Femtosecond pulses are primarily generated at 800 or 1030 nm in Tiisapphire or Yb based systems. To generate fully tunable pulses over the full visible and NIR range, optical parametric amplifiers and in particular white light seeded noncollinear optical parametric amplifiers (NOPA) are now widely used. For highest energy pulses this scheme is expanded to OPCPAs. Energy and beam pointing stability...
The emission and propagation of light in disordered media has always been a topic of interest in science, mainly because in nature this is the most common way of light emission and propagation. This research topic received a particular attention after the report of the first highly efficient random laser (RL) [1]. Indeed a large number of investigations discussing the fundamentals and the applications...
Passively mode-locked fiber lasers are unsurpassed in terms of the beam quality, operation stability, compactness and simplicity of integration. Further power and energy scaling in Nd:YAG [1] and Yb:YAG [2] single crystal fiber (ScF) chirped pulse amplifier (CPA) benefit from the pump guiding and improved heat removal. Compared with Nd:YAG crystals, Yb:YAG has significantly lower fractional heating.
The Petawatt Field Synthesizer (PFS) is an OPCPA driven light source that is currently being developed at the Max-Planck-Institut für Quantenoptik in Garching, Germany. The target parameters are few-cycle, waveform-controlled light pulses with a repetition rate of 10 Hz and a peak power in the Petawatt regime [1]. The system relies on a cascaded broadband OPCPA that is pumped by a picosecond, all-diode-pumped...
Surface states have a fundamental role in many modem technologies as well as in the field-matter interaction exhibited by material surfaces. Their manipulation can be used to functionalise surfaces into devices, enabling or enhancing specific physical mechanism [1]. Many rising technologies, such as photovoltaic metasurfaces, rely on thin-layer semiconductors [2, 3]. Most semiconductor surfaces exhibit...
Several fields of research would benefit from the development of new high energy, high average power laser systems. One example is laser driven x-ray generation that is typically based on joule class lasers with a repetition rate of a few hertz. However, to facilitate shorter measuring times, lasers with repetition rates on the order of kHz and a pulse energy of hundreds of mJ are required [1]. Such...
Hybrid organic-inorganic metal halide perovskites represent a remarkable success story in recent materials science applied to optoelectronic devices, thanks to the demonstrations of solution-process solar cells with conversion efficiencies in excess of 20% and very promising LEDs. The peculiarities of perovskites are thought to stem from a blend of organic materials features, like easy fabrication...
Integrating single-photon sources into on-chip optical circuits is a challenge for scalable quantum-photonic technologies. Despite a plethora of single-photon sources reported to-date, all-electrical operation has been reported for only a few. The attractiveness of singlephoton sources in layered materials stems from their ability to operate at the fundamental limit of single-layer thickness, foreseeing...
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