The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Microresonators and lasers on the micro- and nanoscale are potential candidates for spectroscopic applications and sensing elements. The optical properties of these devices enable highly sensitive elements in biophotonics. They can be integrated in lab-on-chip platforms and act as biosensors for label-free detection of molecules in point-of-care diagnosis. One of the most promising resonators type...
Their inherently broadband gain and high value of the third order nonlinearity makes quantum cascade lasers (QCLs) ideal candidates for frequency comb generation in the terahertz (THz) and mid-infrared (midIR) spectral ranges. In recent years, it has been demonstrated that free running QCLs can produce broad comb spectra, even without any special endeavour to induce phase-locking of the lasing modes...
Currently lasers are perceived as unique light that can produce specific states of matter through selective manipulations that could not be realized using any other conventional incoherent addition of thermal or electronic energy to a system. Although the selective laser chemistry is still a dream, the selective control of material processing done by optimization of laser intensity, as well as the...
In the past years rare-earth-doped fiber lasers have emerged as attractive and power scalable solid-state laser concept due to the outstanding thermo-optical properties of an actively doped fiber. The large ratio of surface to active volume of such a fiber ensures excellent heat dissipation, furthermore the beam quality is defined by the refractive index profile of the active core and is therefore...
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)...
Fiber and bulk lasers form two distinct classes of solid-state laser, both of which have achieved tremendous success in various arenas, but they are not without their limitations. The long, thin geometry of a fiber allows excellent heat dissipation, which combined with a waveguiding structure provides stronger resilience to thermally-induced mode distortions than in bulk lasers, allowing diffraction-limited...
Highly nonlinear spatial-temporal patterns are inevitable features of lasing in the low-Q (bad) cavities where a photon lifetime, TE, is less than a polarization relaxation time (a lifetime of the optical dipole oscillations), T2, of the individual active centers excited by pumping [1]. A theoretical analysis of the spatial-temporal dynamics of the field and its spectral and correlation features in...
Indium Tin Oxide (ITO) is a highly conductive and transparent thin film used in modern technological applications; i.e organic light emitting devices (OLED) [1], transparent flat touch panel displays (FPD) [2], and solar cells [3]. Fast and highly precise selective patterning of ITO with controlled depth and width of scribed lines, is required for such applications. The pattering for such applications...
Few-cycle femtosecond pulses (∼10 fs) have proven their interest in highly-controlled interaction with dielectric materials [1]. For efficient single-shot ablation, intensities exceeding 1014 W/cm2 at the target surface are required. However, for such intensities, working in air ambience rapidly yields significant nonlinear spatial distortion of the beam in the pre-focal region, or even air ionization,...
Fiber lasers have come to a great prominence when it comes to stable high power and excellent beam quahty. They are used in industry for material processing, space apphcations as well as in medicine for precise surgery. Despite their widespread application they are not understood completely when it comes to longitudinal mode (LM) with stochastic phase relations and resulting nonlinear effects like...
Raman fiber lasers (RFLs) are treated as perspective laser sources in spectral bands which are not available from rare-earth (RE) doped fiber lasers. Raman lasing can be easily obtained from 1.1 to 2 μm in single-mode fibers that are core-pumped by RE-doped fiber lasers generating single transverse mode. However, the RFL generation below 1, Mm is difficult because of a lack of suitable high-power...
High-power single-frequency lasers are very attractive for a wide range of applications such as nonlinear conversion, gravitational wave detection, atom trapping or LIDAR. Power scaling in single-frequency regime is a challenging domain of research. In fact, nonlinear effect such as stimulated Brillouin scattering (SBS) is the primary power limitation in single-frequency amplifiers. To mitigate SBS,...
High-peak-power longwave OPAs operating above the wavelength of 5μm [1] require high-energy picosecond pump pulses >2 μm. These can be generated directly in laser amplifiers, e.g. Ho-doped [1, 2] or via cascaded OPAs [3]. Burst-mode pump lasers offer great advantages over single-pulse amplifiers because they help overcoming the challenges of chirped-pulse as well as direct picosecond pulse amplifiers...
We experimentally and theoretically examined the mode structure of half-disk lasers fabricated by cleaving whispering gallery mode (WGM)-disk lasers. The WGM lasers with a radii R of 50–150 μm emitting near 2.2 μm were fabricated using the GaSb-based quantum well structure [1]. The cleavage usually passes not through the centre of the disk with the deviation δ/R up to 20 % (Fig. 1a). Recently we have...
Dual-wavelength and tri-wavelength operation of solid-state lasers has been attracting a great deal of attention, due to the need for such sources in applications like coherent terahertz generation [1]. Multicolor laser operation has been shown in many solid-state laser gain media including Nd:YAG, Yb:KGW, Tm:YAP, Cr:LiSAF, Alexandrite, Tm:CaYAlO4, and Ti:Sapphire. Most of the earlier studies report...
Dual-frequency (DF) solid-state lasers provide very interesting characteristics for application in Radar-Lidar, metrology or microwave photonics systems. Indeed, such lasers sustaining the oscillation of two cross-polarized modes with different frequencies provide stable and tunable optically carried microwave beat-notes [1, 2]. Nevertheless, solid-state DF lasers suffer from resonant excess intensity...
Solar-pumped Nd:YAG lasers are a promising renewable energy source for applications including the magnesium-hydrogen energy cycle, power beaming and satellite technologies [1]. The major issue that limits the performance of these lasers is the weak absorption of solar radiation due to the low overlap between the solar spectrum and the Nd:YAG absorption spectrum. The symmetry and homogeneity of this...
Recent advances on Ytterbium ultrafast lasers have led to compact and versatile systems with high average output power, potentially high pulse energy and easily tunable repetition rate. Such lasers are well suited for time-resolved pump-probe experiments, a field which involves a wide range of techniques spanning from X-rays diffraction imaging and spectroscopy to asynchronous optical sampling (ASOPS)...
Fully-stabilized optical frequency combs from modelocked lasers are a key component in various applications like optical frequency metrology, optical clocks or ultra-stable microwave generation. The traditional approach to stabilize the carrier-envelope offset (CEO) frequency /ceo in a diode-pumped modelocked laser is via a modulation of the pump current, i.e., by modulating the gain of the modelocked...
Continuous-wave single-longitudinal-mode (SLM) lasers are an important tool for applications exploiting light-matter interactions. However, mature laser technologies using inversion gain media cover only a limited part of the optical spectrum. Therefore, nonlinear frequency conversion is necessary to reach wavelengths outside this range. Conversion using stimulated Raman scattering can be a simple...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.